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Zhang B, Burchill L, Altalhi WAO, Ma HZ, O'Hair RAJ. A fixed-charge model of the N-protomer of 4-aminobenzoic acid to facilitate the study of the unimolecular and bimolecular chemistry of its "neutral" carboxylic acid group. Rapid Commun Mass Spectrom 2024; 38:e9681. [PMID: 38355884 DOI: 10.1002/rcm.9681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/24/2023] [Accepted: 11/25/2023] [Indexed: 02/16/2024]
Abstract
RATIONALE There are a growing number of examples of protomers formed via electrospray ionization (ESI) that do not fragment under mobile proton conditions, giving rise to distinct tandem mass spectra. To model the N-protomer of 4-aminobenzoic acid, here we study the gas-phase unimolecular and bimolecular chemistry of the 4-(carboxyphenyl)trimethylammonium ion. METHODS 4-(Carboxyphenyl)trimethylammonium iodide was synthesized, purified via recrystallization and transferred to the gas phase via ESI. 4-(Carboxyphenyl)trimethylammonium ion, 7, was mass selected and subjected to collision-induced dissociation and ion-molecule reactions in a linear ion trap mass spectrometer. RESULTS The major fragmentation channel for the fixed-charge cation 7 is methyl radical loss, whereas loss of trimethylamine and CO2 represents minor pathways. The free carboxylic acid functional group of 7 is unreactive toward a number of neutral reagents (methanol, acetone, acetonitrile, and N,N'-diisopropylcarbodiimide). 7 reacts very slowly with trimethylborate via addition-elimination, consistent with density functional theory (DFT) calculations that show this reaction is slightly endothermic. The deuterated cation 7(D) undergoes slow D/H exchange with ethanol, and DFT calculations reveal that a flip-flop mechanism operates. CONCLUSIONS The free carboxylic group of 7 is not very reactive toward neutral reagents in the gas phase.
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Affiliation(s)
- Beiang Zhang
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Laura Burchill
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Weam A O Altalhi
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
- Department of Chemistry, Prince Sattam Bin Abdulaziz University, Hotat Bani Tamim, Saudi Arabia
| | - Howard Z Ma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
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Aldajani AMO, Ma HZ, Yang Y, Canty AJ, O'Hair RAJ. The Magnesium Dication and Water Synergistically Promote the Protonolysis of Two of the B-C Bonds in the Tetraphenylborate Anion. J Am Soc Mass Spectrom 2024; 35:636-641. [PMID: 38408905 DOI: 10.1021/jasms.4c00017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Analytes are sampled from both solution phase and gas-phase environments during the ESI process, and thus, the mass spectrum that is measured can reflect both solution and gas-phase conditions. In the gas-phase regime, ion-molecule reactions can influence the types of ions that are observed. Herein, the synergistic effects of a Lewis acid (Mg2+) and background water are shown to lead to protonolysis of two of the B-C bonds of the tetraphenylborate ion in the gas phase, giving rise to different ions at different reaction times in ESI-MS/MS experiments in a linear ion trap mass spectrometer. At short reaction times (1 ms), the expected adduct [Mg(BPh4)]+ is observed. At 10 ms, [(HO)Mg(BPh3)]+ and [(HO)2Mg(BPh2)]+ are observed. At 100 ms, the water adducts [(HO)2Mg(BPh2)(H2O)]+ and [(HO)2Mg(BPh2)(H2O)2]+ appear, and these become the dominant ions at longer reaction times. DFT calculations provide a plausible explanation as to why only [(HO)Mg(BPh3)]+ and [(HO)2Mg(BPh2)]+ but not [(HO)3Mg(BPh)]+ are observed.
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Affiliation(s)
- Asma M O Aldajani
- Department of Chemistry, College of Science, University of Bisha, P.O. Box 551, Bisha 61922, Saudi Arabia
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Howard Z Ma
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Yang Yang
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Allan J Canty
- School of Physical Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia
| | - Richard A J O'Hair
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria 3010, Australia
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Altalhi WAO, Chan B, O'Hair RAJ. Methide Affinity Scale: Key Thermodynamic Data Underpinning Catalysis, Organic Synthesis, and Organometallic and Polymer Chemistry. J Phys Chem A 2024; 128:977-988. [PMID: 38295100 DOI: 10.1021/acs.jpca.3c05974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
Methide transfer reactions play important roles in many areas of chemistry, including the Grignard reaction, in the transmetalation steps of metal-catalyzed cross-coupling reactions, and in the generation of cationic metal polymerization catalysts. Methide affinities (MAs) are the key thermodynamic quantity that underpin such reactions, and yet comprehensive methide affinity scales are poorly developed. Here, B3LYP-D3BJ/def2-TZVP calculations are used to calculate the energy changes (MAs) for cations (MeZ → Z+ + Me-), neutrals (MeY- → Y + Me-), and anions (MeX2- → X- + Me-) derived from permethyl species of all group s and p elements. The MAs range from 2525.8 for the singlet cation F+ to -820.4 kJ/mol for the tetramethylborate anion, Me4B-. The cations show the clearest trends: the MAs in all cases decrease going down the group, while moving across a period, the MAs increase from group 1 to group 2 and then decrease for group 3, remaining about the same or with a modest increase moving to group 4, and then continue to increase across a period to a maximum for the halogens (group 17). The anions and dianions are sensitive to hypervalency; those elements that cannot expand the octet have very unfavorable MAs (e.g., MA of Me4C requires the formation of Me5C- and of Me4B- requires the formation of Me5B2-). To address whether the anion MeY- and dianion MeZ2- are stable, the vertical detachment energies of the anions and dianions were calculated. All of the anions are thermodynamically stable with respect to electron loss, except for Me4N-, while the dianions are all thermodynamically unstable with respect to electron loss. The kinetic stability of the dianions with respect to methide and electron loss was also evaluated for the lowest MAs. The only dianions that might be kinetically stable and observable in the gas phase are Me4Ca2-, Me4Sr2-, and Me4Ba2-. The dianion CF3CaF32- is predicted to be both thermodynamically and kinetically stable in the gas phase.
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Affiliation(s)
- Weam A O Altalhi
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Melbourne, Victoria 3010, Australia
- Department of Chemistry, Prince Sattam Bin Abdulaziz University, Hotat Bani Tamim 16511, Saudi Arabia
| | - Bun Chan
- Graduate School of Engineering, Nagasaki University, Bunkyo 1-14, Nagasaki 852-8521, Japan
- Computational Molecular Science Research Team, RIKEN Center for Computational Science, 7-1-26 minatojima-minami, Cyuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Melbourne, Victoria 3010, Australia
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Ma HZ, Canty AJ, O'Hair RAJ. Liberation of carbon monoxide from formic acid mediated by molybdenum oxyanions. Dalton Trans 2023; 52:15734-15746. [PMID: 37843527 DOI: 10.1039/d3dt01983g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Multistage mass spectrometry experiments, isotope labelling and DFT calculations were used to explore whether selective decarbonylation of formic acid could be mediated by molybdate anions [(MoO3)x(OH)]- (x = 1 and 2) via a formal catalytic cycle involving two steps. In step 1, both molybdate anions undergo gas-phase ion-molecule reactions (IMR) with formic acid to produce the coordinated formates [(MoO3)x(O2CH)]- and H2O. In step 2, both coordinated formates [(MoO3)x(O2CH)]- undergo decarbonylation under collision-induced dissociation (CID) conditions to reform the molybdate anions [(MoO3)x(OH)]- (x = 1 and 2), thus closing a formal catalytic cycle. In the case of [MoO3(O2CH)]- an additional decarboxylation channel also occurs to yield [MoO3(H)]-, which is unreactive towards formic acid. The reaction between [Mo18O3(18OH)]- and formic acid gives rise to [Mo18O3(O2CH)]- highlighting that ligand substitution occurs without 18O/16O exchange between the coordinated 18OH ligand and HC16O2H. The reaction between [(MoO3)x(OD)]- (x = 1 and 2) and DCO2H initially produces [(MoO3)x(OH)]- (x = 1 and 2), indicating that D/H exchange occurs. DFT calculations were carried out to investigate the reaction mechanisms and energetics associated with both steps of the formal catalytic cycle and to better understand the competition between decarbonylation and decarboxylation, which is crucial in developing a selective catalyst. The CO and CO2 loss channels from the monomolybdate anion [MoO3(O2CH)]- have similar barrier heights which is in agreement with experimental results where both fragmentation channels are observed. In contrast, the dimolybdate anion is more selective, since the decarbonylation pathway of [(MoO3)2(O2CH)]- is both kinetically and thermodynamically favoured, which agrees with experimental observations where the CO loss channel is solely observed.
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Affiliation(s)
- Howard Z Ma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Allan J Canty
- School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
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Brydon SC, Thomson C, O'Hair RAJ, White JM. Electronic and Steric Effects on the Reactivity of Seleniranium Ions with Alkenes in the Gas Phase. J Org Chem 2023; 88:9629-9644. [PMID: 36705983 DOI: 10.1021/acs.joc.2c02233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Gas phase ion-molecule reactions between seleniranium ions, R-c-SeCH2CH2+, and cis-cyclooctene were used to probe electronic and steric effects of substituents on kinetics and branching ratios. The second-order rate coefficients increased in the order p-OMeC6H4 < C6H5 < p-BrC6H4 < p-CF3C6H4 < m-NO2C6H4, giving a Hammett plot with R2 = 0.98 and ρ = +1.66. The two main pathways include direct transfer of the selenium moiety to the incoming alkene (π-ligand exchange) and the less favored ring-opening by attack at an iranium carbon to give a cis-bicyclic selenonium ion as supported by density functional theory (DFT) calculations. Branching ratios of each pathway indicated that electron-withdrawing groups directed more attack at carbon than selenium in agreement with previous solution-phase results. Increased steric bulk on selenium was investigated by changing the R group from a methyl to t-butyl, which not only shut down π-ligand exchange but also significantly reduced the overall reactivity. Finally, the reactivity of the iranium ion derived from Se-methylselenocysteine was investigated and shown to react faster and favor π-ligand exchange as the leaving group was changed from ethene to acrylic acid.
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Affiliation(s)
- Samuel C Brydon
- School of Chemistry and Bio21 Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Catriona Thomson
- School of Chemistry and Bio21 Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Jonathan M White
- School of Chemistry and Bio21 Institute, The University of Melbourne, Parkville, VIC 3010, Australia
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Ma HZ, Canty AJ, O'Hair RAJ. Near thermal, selective liberation of hydrogen from formic acid catalysed by copper hydride ate complexes. Dalton Trans 2023; 52:1574-1581. [PMID: 36656079 DOI: 10.1039/d2dt03764e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A near thermal two-step catalytic cycle for the selective release of hydrogen from formic acid by mononuclear cuprate anions was revealed using multistage mass spectrometry experiments, deuterium labelling and DFT calculations. In gas-phase ion-molecule reactions, mononuclear copper hydride anions [(L)Cu(H)]- (where L = H-, O2CH-, BH4- and CN-) were found to react with formic acid (HCO2H) to yield [(L)Cu(O2CH)]- and H2. The copper formate anions [(L)Cu(O2CH)]- can decarboxylate via collision-induced dissociation (CID) to reform the copper hydride [(L)Cu(H)]-, thereby closing the two-step catalytic cycle. Analogous labelling experiments with d1-formic acid (DCO2H) reveal that the decarboxylation process also occurs spontaneously. A kinetic study was carried out to provide further insights into the species involved in this reaction. Energetics from density functional theory (DFT) calculations show that the key decarboxylation step can occur without CID, thus in support of experimental observations.
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Affiliation(s)
- Howard Z Ma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Allan J Canty
- School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
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Choudhari M, Xu J, McKay AI, Guerrin C, Forsyth C, Ma HZ, Goerigk L, O'Hair RAJ, Bonnefont A, Ruhlmann L, Aloise S, Ritchie C. A photo-switchable molecular capsule: sequential photoinduced processes. Chem Sci 2022; 13:13732-13740. [PMID: 36544719 PMCID: PMC9710229 DOI: 10.1039/d2sc04613j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 10/21/2022] [Indexed: 12/24/2022] Open
Abstract
The metastable trilacunary heteropolyoxomolybdate [PMo9O31(py)3]3- - {PMo9}; py = pyridine) and the ditopic pyridyl bearing diarylethene (DAE) (C25H16N2F6S2) self-assemble via a facile ligand replacement methodology to yield the photo-active molecular capsule [(PMo9O31)2(DAE)3]6-. The spatial arrangement and conformation of the three DAE ligands are directed by the surface chemistry of the molecular metal oxide precursor with exclusive ligation of the photo-active antiparallel rotamer to the polyoxometalate (POM) while the integrity of the assembly in solution has been verified by a suite of spectroscopic techniques. Electrocyclisation of the three DAEs occurs sequentially and has been investigated using a combination of steady-state and time-resolved spectroscopies with the discovery of a photochemical cascade whereby rapid photoinduced ring closure is followed by electron transfer from the ring-closed DAE to the POM in the latent donor-acceptor system on subsequent excitation. This interpretation is also supported by computational and detailed spectroelectrochemical analysis. Ring-closing quantum yields were also determined using a custom quantum yield determination setup (QYDS), providing insight into the impact of POM coordination on these processes.
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Affiliation(s)
| | - Jingjing Xu
- School of Chemistry, Monash UniversityClaytonVictoria3800Australia,College of Chemistry and Materials Science, Shanghai Normal UniversityShanghai 200234China
| | | | - Clément Guerrin
- Université de Lille, CNRS, UMR 8516 – LASIRE – Laboratoire de Spectroscopie pour les Interactions, la Réactivité et l’EnvironnementLille F-59000France
| | - Craig Forsyth
- School of Chemistry, Monash UniversityClaytonVictoria3800Australia
| | - Howard Z. Ma
- School of Chemistry, University of MelbourneMelbourne3010VictoriaAustralia
| | - Lars Goerigk
- School of Chemistry, University of MelbourneMelbourne3010VictoriaAustralia
| | | | - Antoine Bonnefont
- Laboratoire d’Electrochimie et Chimie Physique du Corps Solide, Institut de Chimie de Strasbourg, UMR 7177 CNRS-Université de Strasbourg4, rue Blaise PascalStrasbourg 67000France
| | - Laurent Ruhlmann
- Laboratoire d’Electrochimie et Chimie Physique du Corps Solide, Institut de Chimie de Strasbourg, UMR 7177 CNRS-Université de Strasbourg4, rue Blaise PascalStrasbourg 67000France
| | - Stephane Aloise
- Université de Lille, CNRS, UMR 8516 – LASIRE – Laboratoire de Spectroscopie pour les Interactions, la Réactivité et l’EnvironnementLille F-59000France
| | - Chris Ritchie
- School of Chemistry, Monash UniversityClaytonVictoria3800Australia
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Ma HZ, Canty AJ, O'Hair RAJ. Electrospray Ionization Tandem Mass Spectrometry and DFT Survey of Copper(I) Ate Complexes Containing Coordinated Borohydride Anions. J Am Soc Mass Spectrom 2022; 33:1443-1452. [PMID: 35749300 DOI: 10.1021/jasms.2c00103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Copper(I) borohydride ate complexes of the type Cat+[XCu(BH4)]- have been previously postulated as intermediates in the reactions of copper salts with borohydride. Negative ion electrospray ionization of an acetonitrile solution of copper(I) phenylacetylide with a 10-fold excess of sodium borohydride (NaBH4) revealed the formation of a diverse range of mononuclear, dinuclear and trinuclear cuprates with different numbers of BH4-, H- and CN- ligands, the latter likely being formed by abstraction of CN- from the acetonitrile solvent. Collision-induced dissociation was used to examine the fragmentation reactions of the following borohydride containing cuprates: [Cu(H)(BH4)]-, [Cu(BH4)2]-, [Cu(BH4)(CN)]-, [Cu2(H)(BH4)2]-, [Cu2(H)2(BH4)]-, [Cu2(BH4)2(CN)]-, [Cu2(H)(BH4)(CN)]-, [Cu3(H)(BH4)3]-, [Cu3(H)2(BH4)2]-, [Cu3(H)3(BH4)]-, [Cu3(BH4)2(CN)2]-, and [Cu3(H)(BH4)2(CN)]-. In all cases, BH3 loss is observed. For many of the dinuclear and trinuclear complexes cluster fragmentation by loss of CuH was also observed. In the case of [Cu2(H)2(BH4)]- and [Cu3(H)3(BH4)]-, loss of H2 was also observed. DFT calculations were used to explore potential structures of the various borohydride-containing cuprates and to predict the overall reaction energetics for the various fragmentation channels.
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Affiliation(s)
- Howard Z Ma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Allan J Canty
- School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
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Fabijanczuk KC, Altalhi WAO, Aldajani AMO, Canty AJ, McLuckey SA, O'Hair RAJ. Ion-pairs as a gateway to transmetalation: aryl transfer from boron to nickel and magnesium. Dalton Trans 2022; 51:5699-5705. [PMID: 35323833 DOI: 10.1039/d2dt00746k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gas-phase ion-ion reactions between tris-1,10-phenantholine metal dications, [(phen)3M]2+ (where M = Ni and Mg), and the tetraphenylborate anion yield the ion-pairs {[(phen)3M]2+[BPh4]-}+. The ion-pairs undergo transmetalation upon loss of a phen ligand to give the organometallic complexes [(phen)2M(Ph)]+. DFT calculations, used to determine the energy barriers for the transmetalation reactions and the hydrolysis reactions, are entirely consistent with the experimental results.
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Affiliation(s)
| | - Weam A O Altalhi
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Victoria 3010, Australia. .,Department of Chemistry, Prince Sattam Bin Abdulaziz University, Hotat Bani Tamim, 16511 Saudi Arabia
| | - Asma M O Aldajani
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Victoria 3010, Australia. .,Department of Chemistry, College of Science, University of Bisha, Bisha 61922, P.O. Box 551, Saudi Arabia
| | - Allan J Canty
- School of Physical Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia
| | - Scott A McLuckey
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Victoria 3010, Australia.
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Brydon SC, da Silva G, O'Hair RAJ, White JM. Experimental and theoretical investigations into the mechanisms of haliranium ion π-ligand exchange reactions with cyclic alkenes in the gas phase. Phys Chem Chem Phys 2021; 23:25572-25589. [PMID: 34783339 DOI: 10.1039/d1cp04494j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Haliranium ions are intermediates often involved in complex cyclisations, where their structure allows for control over stereospecific outcomes. Extending previous studies into their structure and reactivity in the gas phase, this work focuses on the bimolecular reactivity of ethyl bromiranium and iodiranium ions with cyclic alkenes. The products observed via mass spectrometry were broadly attributed to either addition by cyclohexene at the iranium carbon or attack at the heteroatom to undergo associative π-ligand exchange. The model proposed was supported by both kinetic experiments and DFT calculations, where the rate of parent ion consumption proceeded at the collision rate (Br: k2 = 1.25 × 10-9 and I: k2 = 1.28 × 10-9 cm3 molecule-1 s-1) with the subsequent partitioning dependent on the relative stability of the initial intermediates and the relatively large barriers present in the addition pathway. Exploration of the effect of cycloalkene ring strain on the iodiranium ion reactivity was conducted with a series of crossover experiments with 50 : 50 mixtures of either cyclohexene or cis-cyclooctene and styrene, where the outcomes were dependent on the competing ring strain relief gained by reaction with each neutral. The nature of the exchange transition state was determined to be pseudocoarctate following both natural bond orbital (NBO) and anisotropy of the induced current density (ACID) analysis.
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Affiliation(s)
- Samuel C Brydon
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Gabriel da Silva
- Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Jonathan M White
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria 3010, Australia.
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MacAleese L, Chan B, Bouakil M, Dugourd P, O'Hair RAJ. Photo-control of bimolecular reactions: reactivity of the long-lived Rhodamine 6G triplet excited state with ˙NO. Phys Chem Chem Phys 2021; 23:25038-25047. [PMID: 34605499 DOI: 10.1039/d1cp02626g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Photo-chemistry provides a non-intuitive but very powerful way to probe kinetically limited, sometimes thermodynamically non-favored reactions and, thus, access highly specific products. However, reactivity in the excited state is difficult to characterize directly, due to short lifetimes and challenges in controlling the reaction medium. Among photo-activatable reagents, rhodamine dyes find widespread uses due to a number of favorable properties including their high absorption coefficient. Their readily adaptable synthesis allows development of tailor-made dyes for specific applications. Remarkably, few studies have directly probed the chemical reactivity of their triplet excited state. Here we present a new conceptual approach to examine the specific chemistry of the triplet excited state. We have developed a pump (488 nm) - probe (600 nm) strategy to examine the gas-phase lifetime and reactivity of the triplet cation of Rhodamine 6G (3Rh6G+) in an ion trap mass spectrometer. The confounding effects of solvent, aggregation and formation of other reactive intermediates is thus avoided allowing fundamental reactivity to be explored. In the presence, in the ion trap, of helium seeded with 1% of nitric oxide (˙NO) (∼ 60 ion/˙NO collisions per second), the triplet lifetime is shortened from 1.9 s to 0.7 s. Simultaneously, the reaction products [Rh6G-H]˙+ and [Rh6G-H + NO]+ are observed. Reaction of 3Rh6G+ with ˙NO2 yields [Rh6G-H]˙+, [Rh6G-H + NO2]+ and [Rh6G-2H]+. None of these products are observed for the singlet, 1Rh6G+. DFT calculations suggest a stepwise mechanism only allowed from 3Rh6G+, in which H atom abstraction by ˙NOx (x = 1 or 2) yields [Rh6G-H]˙+ which, then, reacts with another ˙NOx molecule. This illustrates the power of light to initiate specific chemical reactions, and the relevance of gas-phase ion-molecule reaction approaches to understand stepwise reaction mechanism from specific excited states.
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Affiliation(s)
- Luke MacAleese
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS - Institut Lumière Matière (iLM), F-69622, LYON, France.
| | - Bun Chan
- Division of Chemistry and Materials Science, Nagasaki University - 1-14 Bunkyo, Nagasaki, 852-8521, Japan
| | - Mathilde Bouakil
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS - Institut Lumière Matière (iLM), F-69622, LYON, France.
| | - Philippe Dugourd
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS - Institut Lumière Matière (iLM), F-69622, LYON, France.
| | - Richard A J O'Hair
- School of Chemistry, University of Melbourne - Parkville, Victoria 3010, Australia.
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Auth T, Stein CJ, O'Hair RAJ, Koszinowski K. Origin of the different reactivity of the high-valent coinage-metal complexes [RCuIIIMe3]- and [RAgIIIMe3]- (R = allyl). Chemistry 2021; 28:e202103130. [PMID: 34773654 PMCID: PMC9304237 DOI: 10.1002/chem.202103130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Indexed: 11/27/2022]
Abstract
High‐valent tetraalkylcuprates(iii) and ‐argentates(iii) are key intermediates of copper‐ and silver‐mediated C−C coupling reactions. Here, we investigate the previously reported contrasting reactivity of [RMiiiMe3]− complexes (M=Cu, Ag and R=allyl) with energy‐dependent collision‐induced dissociation experiments, advanced quantum‐chemical calculations and kinetic computations. The gas‐phase fragmentation experiments confirmed the preferred formation of the [RCuMe]− anion upon collisional activation of the cuprate(iii) species, consistent with a homo‐coupling reaction, whereas the silver analogue primarily yielded [AgMe2]−, consistent with a cross‐coupling reaction. For both complexes, density functional theory calculations identified one mechanism for homo coupling and four different ones for cross coupling. Of these pathways, an unprecedented concerted outer‐sphere cross coupling is of particular interest, because it can explain the formation of [AgMe2]− from the argentate(iii) species. Remarkably, the different C−C coupling propensities of the two [RMiiiMe3]− complexes become only apparent when properly accounting for the multi‐configurational character of the wave function for the key transition state of [RAgMe3]−. Backed by the obtained detailed mechanistic insight for the gas‐phase reactions, we propose that the previously observed cross‐coupling reaction of the silver complex in solution proceeds via the outer‐sphere mechanism.
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Affiliation(s)
- Thomas Auth
- Georg-August-Universität Göttingen: Georg-August-Universitat Gottingen, Institut für Organische und Biomolekulare Chemie, GERMANY
| | - Christopher J Stein
- University of Duisburg-Essen: Universitat Duisburg-Essen, Faculty of Physics, Lotharstr. 1, 47057, Duisburg, GERMANY
| | - Richard A J O'Hair
- University of Melbourne, School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, AUSTRALIA
| | - Konrad Koszinowski
- Georg-August-Universität Göttingen: Georg-August-Universitat Gottingen, Institut für Organische und Biomolekulare Chemie, GERMANY
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13
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O'Hair RAJ. ORGANOMETALLIC GAS-PHASE ION CHEMISTRY AND CATALYSIS: INSIGHTS INTO THE USE OF METAL CATALYSTS TO PROMOTE SELECTIVITY IN THE REACTIONS OF CARBOXYLIC ACIDS AND THEIR DERIVATIVES. Mass Spectrom Rev 2021; 40:782-810. [PMID: 32965774 DOI: 10.1002/mas.21654] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 08/02/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
Carboxylic acids are valuable organic substrates as they are widely available, easy to handle, and exhibit structural and functional variety. While they are used in many standard synthetic protocols, over the past two decades numerous studies have explored new modes of metal-mediated reactivity of carboxylic acids and their derivatives. Mass spectrometry-based studies can provide fundamental mechanistic insights into these new modes of reactivity. Here gas-phase models for the following catalytic transformations of carboxylic acids and their derivatives are reviewed: protodecarboxylation; dehydration; decarbonylation; reaction as coordinated bases in C-H bond activation; remote functionalization and decarboxylative C-C bond coupling. In each case the catalytic problem is defined, insights from gas-phase studies are highlighted, comparisons with condensed-phase systems are made and perspectives are reached. Finally, the potential role for mechanistic studies that integrate both gas- and condensed-phase studies is highlighted by recent studies on the discovery of new catalysts for the selective decomposition of formic acid and the invention of the new extrusion-insertion class of reactions for the synthesis of amides, thioamides, and amidines. © 2020 John Wiley & Sons Ltd. Mass Spec Rev.
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Affiliation(s)
- Richard A J O'Hair
- School of Chemistry, University of Melbourne, Victoria, 3010, Australia
- Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Victoria, 3010, Australia
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14
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Bathie F, Stewart AWE, Canty AJ, O'Hair RAJ. Dissecting transmetalation reactions at the molecular level: C-B versus F-B bond activation in phenyltrifluoroborate silver complexes. Dalton Trans 2021; 50:1496-1506. [PMID: 33439189 DOI: 10.1039/d0dt03309j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The gas-phase unimolecular reactions of the silver(i) complex [Ag(PhBF3)2]-, formed via electrospray ionisation mass spectrometry of solutions containing the phenyltrifluoroborate salt and AgNO3, are examined. Upon collision induced dissociation (CID) three major reaction channels were observed for [Ag(PhBF3)2]-: Ph- group transfer via a transmetalation reaction to yield [PhAg(PhBF3)]-; F- transfer to produce [FAg(PhBF3)]-; and release of PhBF3-. The anionic silver product complexes of these reactions, [LAg(PhBF3)]- (where L = Ph and F), were then mass-selected and subjected to a further stage of CID. [PhAg(PhBF3)]- undergoes a Ph- group transfer via transmetalation to yield [Ph2Ag]- with loss of BF3. [FAg(PhBF3)]- solely fragments via loss of BF4-, a reaction that involves Ph- group transfer from B to Ag in conjunction with F- transfer from Ag to B. Density functional theory (DFT) calculations on the various competing pathways reveal that: (i) the overall endothermicities govern the experimentally observed product ion abundances; (ii) the Ph- group and F- transfer reactions proceed via late transition states; and (iii) formation of BF4- from [FAg(PhBF3)]- is a multistep reaction in which Ph- group transfer from B to Ag proceeds first to produce a [FAgPh(BF3)]- complex in which the BF3 moiety is initially weakly bound to the ipso-carbon of the phenyl group and then migrates across the linear [FAgPh]- moiety from C to Ag to F yielding [PhAg(BF4)]-, which can then dissociate via loss of PhAg.
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Affiliation(s)
- Fiona Bathie
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia. and School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia.
| | - Adam W E Stewart
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia. and School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia.
| | - Allan J Canty
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia. and School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia.
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia. and School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia.
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15
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Parker K, Weragoda GK, Pho V, Canty AJ, Polyzos A, O'Hair RAJ, Ryzhov V. Gas‐Phase Models for the Nickel‐ and Palladium‐Catalyzed Deoxygenation of Fatty Acids. ChemCatChem 2020. [DOI: 10.1002/cctc.202000908] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kevin Parker
- Department of Chemistry and Biochemistry Northern Illinois University DeKalb IL 60115 USA
| | | | - Victoria Pho
- Department of Chemistry and Biochemistry Northern Illinois University DeKalb IL 60115 USA
| | - Allan J. Canty
- School of Natural Sciences-Chemistry University of Tasmania Hobart Tasmania 7001 Australia
| | - Anastasios Polyzos
- CSIRO Manufacturing Research Way Clayton VIC 3168 Australia
- School of Chemistry The University of Melbourne Victoria 3010 Australia
| | - Richard A. J. O'Hair
- School of Chemistry Bio21 Institute of Molecular Science and Biotechnology The University of Melbourne Victoria 3010 Australia
| | - Victor Ryzhov
- Department of Chemistry and Biochemistry Northern Illinois University DeKalb IL 60115 USA
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16
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Ma HZ, McKay AI, Canty AJ, O'Hair RAJ. Using electrospray ionization-tandem mass spectrometry to explore formation and gas-phase chemistry of silver nanoclusters generated from the reaction of silver salts with NaBH 4 in the presence of bis(diphenylarsino)methane. J Mass Spectrom 2020; 56:e4590. [PMID: 32721080 DOI: 10.1002/jms.4590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/08/2020] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
Electrospray ionization-mass spectrometry (ESI-MS) of mixtures of AgBF4 or AgNO3 with the capping ligand bis(diphenylarsino)methane ((Ph2 As)2 CH2 = dpam) in a solution of acetonitrile revealed the formation of the following cations: [Ag(CH3 CN)(dpam)]+ , [Ag(dpam)2 ]+ , [Ag2 (Cl)(dpam)2 ]+ , and [Ag3 (Cl)2 (dpam)3 ]+ . Addition of NaBH4 to these solutions results in the formation of the cluster cations [Ag2 (BH4 )(dpam)2 ]+ , [Ag2 (BH4 )(dpam)3 ]+ , [Ag3 (H)(BH4 )(dpam)3 ]+ , [Ag3 (BH4 )2 (dpam)3 ]+ , [Ag3 (H)(Cl)(dpam)3 ]+ , and [Ag3 (I)(BH4 )(dpam)3 ]+ , as established by ESI-MS. Use of NaBD4 confirmed that borohydride is the source of the hydride in these clusters. An Orbitrap Fusion LUMOS mass spectrometer was used to explore the gas-phase unimolecular chemistry of selected clusters via multistage mass spectrometry (MSn ) experiments employing low-energy collision-induced dissociation (CID) and high-energy collision-induced dissociation (HCD) experiments. The borohydride containing clusters fragment via two competing pathways: (i) ligand loss and (ii) B-H bond activation involving BH3 loss. Density functional theory (DFT) calculations were used to calculate the energetics of the optimized structures for all precursor ions, fragment ions, and neutrals and to estimate the reaction endothermicities. Generally, there is reasonable agreement between the most abundant product ion formed and the predicted endothermicity of the associated reaction channel. The DFT calculations predicted that the novel dimer [Ag2 (BH4 )(dpam)2 ]+ has a paddlewheel structure in which the dpam and BH4 - ligands bridge both silver centers.
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Affiliation(s)
- Howard Z Ma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria, Australia
| | - Alasdair I McKay
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria, Australia
| | - Allan J Canty
- School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria, Australia
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17
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Yang Y, Canty AJ, O'Hair RAJ. Gas-phase studies of copper(I)-mediated CO 2 extrusion followed by insertion of the heterocumulenes CS 2 or phenylisocyanate. J Mass Spectrom 2020; 56:e4579. [PMID: 32578305 DOI: 10.1002/jms.4579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/17/2020] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
The gas-phase extrusion-insertion reactions of the copper complex [bathophenanthroline (Bphen)CuI (O2 CC6 H5 )]2- , generated via electrospray ionization, was studied in a linear ion trap mass spectrometer with the combination of collision-induced dissociation (CID) and ion-molecule reaction (IMR) events. Multistage mass spectrometry (MSn ) experiments and density functional theory (DFT) demonstrated that extrusion of carbon dioxide from [(Bphen)Cu(O2 CC6 H5 )]2- (CID) gives the organometallic intermediate [(Bphen)Cu(C6 H5 )]2- , which subsequently reacts with carbon disulfide (IMR) via insertion to yield [(Bphen)Cu (SC(S)C6 H5 )]2- . The fragmentation of the product ion resulted in the formation of [Bphen]2- , [(Bphen)Cu]- and C6 H5 CS2 - under CID conditions. The formation of the latter two charge separation products thus provides evidence of C-C bond formation in the IMR step. Although analogous studies with isocyanate, which is isoelectronic with CS2 , showed a poor reactivity in the gas phase, the mechanistic understanding obtained from these model studies encourages future development of a solution phase protocol for the synthesis of amides from carboxylic acids and isocyanates mediated by copper(I) complexes.
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Affiliation(s)
- Yang Yang
- School of Chemistry, Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Australia
| | - Allan J Canty
- School of Natural Sciences-Chemistry, University of Tasmania, Hobart, Australia
| | - Richard A J O'Hair
- School of Chemistry, Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Australia
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18
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McKay AI, Altalhi WAO, McInnes LE, Czyz ML, Canty AJ, Donnelly PS, O'Hair RAJ. Identification of the Side Products That Diminish the Yields of the Monoamidated Product in Metal-Catalyzed C-H Amidation of 2-Phenylpyridine with Arylisocyanates. J Org Chem 2020; 85:2680-2687. [PMID: 31971390 DOI: 10.1021/acs.joc.9b02831] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The Ru(II)-catalyzed amidation of 2-arylpyridines with aryl isocyanates via C-H bond activation is less efficient than described previously, due to the formation of a series of side products, which were readily identified using direct infusion electrospray mass spectrometry and high-performance liquid chromatography-mass spectrometry.
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Affiliation(s)
- Alasdair I McKay
- School of Chemistry , The University of Melbourne , Melbourne , Victoria 3010 , Australia.,Bio21 Institute of Molecular Science and Biotechnology , The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Weam A O Altalhi
- School of Chemistry , The University of Melbourne , Melbourne , Victoria 3010 , Australia.,Bio21 Institute of Molecular Science and Biotechnology , The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Lachlan E McInnes
- School of Chemistry , The University of Melbourne , Melbourne , Victoria 3010 , Australia.,Bio21 Institute of Molecular Science and Biotechnology , The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Milena L Czyz
- School of Chemistry , The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Allan J Canty
- School of Natural Sciences-Chemistry , University of Tasmania , Private Bag 75 , Hobart , Tasmania 7001 , Australia
| | - Paul S Donnelly
- School of Chemistry , The University of Melbourne , Melbourne , Victoria 3010 , Australia.,Bio21 Institute of Molecular Science and Biotechnology , The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Richard A J O'Hair
- School of Chemistry , The University of Melbourne , Melbourne , Victoria 3010 , Australia.,Bio21 Institute of Molecular Science and Biotechnology , The University of Melbourne , Melbourne , Victoria 3010 , Australia
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19
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Czyz ML, Weragoda GK, Horngren TH, Connell TU, Gomez D, O'Hair RAJ, Polyzos A. Photoexcited Pd(ii) auxiliaries enable light-induced control in C(sp 3)-H bond functionalisation. Chem Sci 2020; 11:2455-2463. [PMID: 34084410 PMCID: PMC8157331 DOI: 10.1039/c9sc05722f] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Herein we report the photophysical and photochemical properties of palladacycle complexes derived from 8-aminoquinoline ligands, commonly used auxiliaries in C–H activation. Spectroscopic, electrochemical and computational studies reveal that visible light irradiation induces a mixed LLCT/MLCT charge transfer providing access to synthetically relevant Pd(iii)/Pd(iv) redox couples. The Pd(ii) complex undergoes photoinduced electron transfer with alkyl halides generating C(sp3)–H halogenation products rather than C–C bond adducts. Online photochemical ESI-MS analysis implicates participation of a mononuclear Pd(iii) species which promotes C–X bond formation via a distinct Pd(iii)/Pd(iv) pathway. To demonstrate the synthetic utility, we developed a general method for inert C(sp3)–H bond bromination, chlorination and iodination with alkyl halides. This new strategy in auxiliary-directed C–H activation provides predictable and controllable access to distinct reactivity pathways proceeding via Pd(iii)/Pd(iv) redox couples induced by visible light irradiation. Visible light irradiation of 8-aminoquinoline Pd(ii) complexes initiates photoinduced electron transfer with alkyl halides, affording C–H halogenation over C–C bond adducts. A method for inert C(sp3)–H bond halogenation (Br, Cl and I) is reported.![]()
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Affiliation(s)
- Milena L Czyz
- School of Chemistry, The University of Melbourne Parkville 3010 Victoria Australia
| | | | - Tyra H Horngren
- School of Chemistry, The University of Melbourne Parkville 3010 Victoria Australia
| | - Timothy U Connell
- School of Science, RMIT University Melbourne Victoria 3000 Australia
| | - Daniel Gomez
- School of Science, RMIT University Melbourne Victoria 3000 Australia
| | - Richard A J O'Hair
- School of Chemistry, The University of Melbourne Parkville 3010 Victoria Australia
| | - Anastasios Polyzos
- School of Chemistry, The University of Melbourne Parkville 3010 Victoria Australia .,CSIRO Manufacturing Research Way Clayton VIC 3168 Australia
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20
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Andrikopoulos B, Sidhu PK, Taggert BI, Nathanael JG, O'Hair RAJ, Wille U. Reaction of Distonic Aryl and Alkyl Radical Cations with Amines: The Role of Charge and Spin Revealed by Mass Spectrometry, Kinetic Studies, and DFT Calculations. Chempluschem 2020. [DOI: 10.1002/cplu.201900706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Benjamin Andrikopoulos
- School of Chemistry Bio21 Institute The University of Melbourne 30 Flemington Road, Parkville Victoria 3010 Australia
| | - Parvinder K. Sidhu
- School of Chemistry Bio21 Institute The University of Melbourne 30 Flemington Road, Parkville Victoria 3010 Australia
| | - Bethany I. Taggert
- School of Chemistry Bio21 Institute The University of Melbourne 30 Flemington Road, Parkville Victoria 3010 Australia
| | - Joses G. Nathanael
- School of Chemistry Bio21 Institute The University of Melbourne 30 Flemington Road, Parkville Victoria 3010 Australia
| | - Richard A. J. O'Hair
- School of Chemistry Bio21 Institute The University of Melbourne 30 Flemington Road, Parkville Victoria 3010 Australia
| | - Uta Wille
- School of Chemistry Bio21 Institute The University of Melbourne 30 Flemington Road, Parkville Victoria 3010 Australia
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21
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Abstract
Metabolic bioactivation of small molecules can produce electrophilic metabolites that can covalently modify proteins and DNA. Paracetamol (APAP) is a commonly used over-the-counter analgesic, and its hepatotoxic side effects have been postulated to be due to the formation of the electrophilic metabolite N-acetylbenzoquinone imine (NAPQI). It has been established that NAPQI reacts to form covalent bonds to the side-chain functional groups of cysteine, methionine, tyrosine, and tryptophan residues. While there have been scattered reports that APAP can form adducts with DNA the nature of these adducts have not yet been fully characterised. Here the four deoxynucleosides, deoxyguanosine (dG), deoxyadenosine (dA), deoxycytidine (dC), and deoxythymidine (dT) were reacted with NAPQI and the formation of adducts was profiled using liquid chromatography–mass spectrometry with positive-ion mode electrospray ionisation and collision-induced dissociation. Covalent adducts were detected for dG, dA, and dC and tandem mass spectrometry (MS/MS) spectra revealed common neutral losses of deoxyribose (116 amu) arising from cleavage of the glyosidic bond with formation of the modified nucleobase. Of the four deoxynucleosides, dC proved to be the most reactive, followed by dG and dA. A pH dependence was found, with greater reactivity being observed at pH 5.5. The results of density functional theory calculations aimed at understanding the relative reactivities of the four deoxynucleosides towards NAPQI are described.
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22
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Ma HZ, McKay AI, Mravak A, Scholz MS, White JM, Mulder RJ, Bieske EJ, Bonačić-Koutecký V, O'Hair RAJ. Structural characterization and gas-phase studies of the [Ag 10H 8(L) 6] 2+ nanocluster dication. Nanoscale 2019; 11:22880-22889. [PMID: 31763652 DOI: 10.1039/c9nr08321a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The reactions between silver salts and borohydrides produce a rich set of products that range from discrete mononuclear compounds through to silver nanoparticles and colloids. Previous studies using electrospray ionization mass spectrometry (ESI-MS) to track the cationic products in solutions containing sodium borohydride, silver(i) tetrafluoroborate and the bisphosphine ligands, L, bis(diphenylphosphino)methane (dppm) and bis(diphenylphosphino)amine (dppa) have identified the dications [Ag10H8(L)6]2+. Here we isolate and structurally characterize [Ag10H8(dppa)6](BF4)2, and [Ag10H8(dppa)6](NO3)2via X-ray crystallography. Both dications have nearly identical structural features consisting of a Ag10 scaffold with the atoms lying on vertices of a bicapped square antiprism. DFT calculations were carried out to suggest potential sites for the hydrides. Ion-mobility mass spectrometry experiments revealed that [Ag10H8(dppa)6]2+ and [Ag10H8(dppm)6]2+ have similar collision cross sections, while multistage mass spectrometry experiments were used to compare their unimolecular gas-phase chemistry. Although the same initial sequential ligand loss followed by cluster fission and H2 evolution is observed, the more acidic N-H of the dppa provides a more labile H for H2 loss and H/D scrambling processes as revealed by isotope labelled experiments.
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Affiliation(s)
- Howard Z Ma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Alasdair I McKay
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Antonija Mravak
- Center of Excellence for Science and Technology-Integration of Mediterranean Region (STIM) at Interdisciplinary Center for Advanced Sciences and Technology (ICAST), University of Split, Poljička cesta 35, Split 21000, Croatia
| | - Michael S Scholz
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Jonathan M White
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Roger J Mulder
- CSIRO Manufacturing, Research Way, Clayton, Victoria 3168, Australia
| | - Evan J Bieske
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Vlasta Bonačić-Koutecký
- Center of Excellence for Science and Technology-Integration of Mediterranean Region (STIM) at Interdisciplinary Center for Advanced Sciences and Technology (ICAST), University of Split, Poljička cesta 35, Split 21000, Croatia and Chemistry Department, Humboldt University of Berlin, Brook-Taylor-Strasse 2, Berlin 12489, Germany
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
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23
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Pandeti S, Ameixa J, Khreis JM, Feketeová L, Chirot F, Reddy TJ, Abdoul-Carime H, Ferreira da Silva F, Denifl S, O'Hair RAJ, Farizon B, Farizon M, Märk TD. Decomposition of protonated ronidazole studied by low-energy and high-energy collision-induced dissociation and density functional theory. J Chem Phys 2019; 151:164306. [PMID: 31675859 DOI: 10.1063/1.5118844] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Nitroimidazoles are important compounds in medicine, biology, and the food industry. The growing need for their structural assignment, as well as the need for the development of the detection and screening methods, provides the motivation to understand their fundamental properties and reactivity. Here, we investigated the decomposition of protonated ronidazole [Roni+H]+ in low-energy and high-energy collision-induced dissociation (CID) experiments. Quantum chemical calculations showed that the main fragmentation channels involve intramolecular proton transfer from nitroimidazole to its side chain followed by a release of NH2CO2H, which can proceed via two pathways involving transfer of H+ from (1) the N3 position via a barrier of TS2 of 0.97 eV, followed by the rupture of the C-O bond with a thermodynamic threshold of 2.40 eV; and (2) the -CH3 group via a higher barrier of 2.77 eV, but with a slightly lower thermodynamic threshold of 2.24 eV. Electrospray ionization of ronidazole using deuterated solvents showed that in low-energy CID, only pathway (1) proceeds, and in high-energy CID, both channels proceed with contributions of 81% and 19%. While both of the pathways are associated with small kinetic energy release of 10-23 meV, further release of the NO• radical has a KER value of 339 meV.
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Affiliation(s)
- Sukanya Pandeti
- Université de Lyon; Université Claude Bernard Lyon1; Institut de Physique des 2 Infinis de Lyon, CNRS/IN2P3 UMR 5822, 69622 Villeurbanne Cedex, France
| | - João Ameixa
- Institut für Ionenphysik und Angewandte Physik, Leopold Franzens Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - Jusuf M Khreis
- Institut für Ionenphysik und Angewandte Physik, Leopold Franzens Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - Linda Feketeová
- Université de Lyon; Université Claude Bernard Lyon1; Institut de Physique des 2 Infinis de Lyon, CNRS/IN2P3 UMR 5822, 69622 Villeurbanne Cedex, France
| | - Fabien Chirot
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, UMR5280 Institut Sciences Analytiques, 69100 Villeurbanne, France
| | - Thota J Reddy
- Analytical Chemistry and Mass Spectrometry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India
| | - Hassan Abdoul-Carime
- Université de Lyon; Université Claude Bernard Lyon1; Institut de Physique des 2 Infinis de Lyon, CNRS/IN2P3 UMR 5822, 69622 Villeurbanne Cedex, France
| | - Filipe Ferreira da Silva
- Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal
| | - Stephan Denifl
- Institut für Ionenphysik und Angewandte Physik, Leopold Franzens Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - Richard A J O'Hair
- School of Chemistry, Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Bernadette Farizon
- Université de Lyon; Université Claude Bernard Lyon1; Institut de Physique des 2 Infinis de Lyon, CNRS/IN2P3 UMR 5822, 69622 Villeurbanne Cedex, France
| | - Michel Farizon
- Université de Lyon; Université Claude Bernard Lyon1; Institut de Physique des 2 Infinis de Lyon, CNRS/IN2P3 UMR 5822, 69622 Villeurbanne Cedex, France
| | - Tilmann D Märk
- Institut für Ionenphysik und Angewandte Physik, Leopold Franzens Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
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24
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Greis K, Yang Y, Canty AJ, O'Hair RAJ. Gas-Phase Synthesis and Reactivity of Ligated Group 10 Ions in the Formal +1 Oxidation State. J Am Soc Mass Spectrom 2019; 30:1867-1880. [PMID: 31183840 DOI: 10.1007/s13361-019-02231-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 04/14/2019] [Accepted: 04/16/2019] [Indexed: 06/09/2023]
Abstract
Electrospray ionization of the group 10 complexes [(phen)M(O2CCH3)2] (phen=1,10-phenanthroline, M = Ni, Pd, Pt) generates the cations [(phen)M(O2CCH3)]+, whose gas-phase chemistry was studied using multistage mass spectrometry experiments in an ion trap mass spectrometer with the combination of collision-induced dissociation (CID) and ion-molecule reactions (IMR). Decarboxylation of [(phen)M(O2CCH3)]+ under CID conditions generates the organometallic cations [(phen)M(CH3)]+, which undergo bond homolysis upon a further stage of CID to generate the cations [(phen)M]+· in which the metal center is formally in the +1 oxidation state. In the case of [(phen)Pt(CH3)]+, the major product ion [(phen)H]+ was formed via loss of the metal carbene Pt=CH2. DFT calculated energetics for the competition between bond homolysis and M=CH2 loss are consistent with their experimentally observed branching ratios of 2% and 98% respectively. The IMR of [(phen)M]+· with O2, N2, H2O, acetone, and allyl iodide were examined. Adduct formation occurs for O2, N2, H2O, and acetone. Upon CID, all adducts fragment to regenerate [(phen)M]+·, except for [(phen)Pt(OC(CH3)2)]+·, which loses a methyl radical to form [(phen)Pt(OCCH3)]+ which upon a further stage of CID regenerates [(phen)Pt(CH3)]+ via CO loss. This closes a formal catalytic cycle for the decomposition of acetone into CO and two methyl radicals with [(phen)Pt]+· as catalyst. In the IMR of [(phen)M]+· with allyl iodide, formation of [(phen)M(CH2CHCH2)]+ was observed for all three metals, whereas for M = Pt also [(phen)Pt(I)]+ and [(phen)Pt(I)2(CH2CHCH2)]+ were observed. Finally, DFT calculated reaction energetics for all IMR reaction channels are consistent with the experimental observations.
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Affiliation(s)
- Kim Greis
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor Straße 2, 12489, Berlin, Germany
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Yang Yang
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Allan J Canty
- School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia.
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25
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O'Hair RAJ, Roithová J, Koszinowski K. A Focus Honoring Helmut Schwarz's Election to the National Academy of Sciences : An Appreciation for and an Interview with Professor Helmut Schwarz. J Am Soc Mass Spectrom 2019; 30:1825-1827. [PMID: 31429051 DOI: 10.1007/s13361-019-02293-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Richard A J O'Hair
- School of Chemistry Bio21 Institute, The University of Melbourne,, Building 102, 30 Flemington Road, Melbourne, Victoria, 3010, Australia.
| | - Jana Roithová
- Radboud University Nijmegen, Institute for Molecules and Materials Department of Spectroscopy and Catalysis, Heyendaalseweg 135, 6525 AJ, Nijmegen, Netherlands
| | - Konrad Koszinowski
- Insitut für Organische und Biomolekulare Chemie, Universität Göttingen Institut für Organische und Biomolekulare Chemie, Tammannstraße 2, 37077, Göttingen, Germany
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26
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Brydon SC, Ren Z, da Silva G, Lim SF, Khairallah GN, Rathjen MJ, White JM, O'Hair RAJ. Experimental and DFT Studies on the Identity Exchange Reactions between Phenyl Chalcogen Iranium Ions and Alkenes. J Phys Chem A 2019; 123:8200-8207. [PMID: 31512874 DOI: 10.1021/acs.jpca.9b06004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The gas-phase ion-molecule identity exchange reactions of phenyl chalcogen iranium ions with alkenes have been examined experimentally in a linear ion trap mass spectrometer by isotope labeling experiments. The nature of both the alkene and the chalcogen play crucial roles, with the bimolecular rates for π-ligand exchange following the order: [PhTe(c-C6H10)]+ + c-C6D10 > [PhTe(C2D4)]+ + C2H4 > [PhSe(c-C6H10)]+ + c-C6D10, with no reaction being observed for [PhSe(C2D4)]+ + C2H4, [PhS(C2D4)]+ + C2H4, and [PhS(c-C6H10)]+ + c-C6D10. The experimental results correlate with RRKM modeling and density functional theory (DFT) calculations, which also demonstrates that these reactions proceed via associative mechanisms. Natural bond orbital (NBO) analysis reveals a shift in the association complexes from a σ-hole interaction to ones mirroring the π-p+ and n-π* at the transition state in accordance with the rates of reaction.
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Affiliation(s)
- Samuel C Brydon
- School of Chemistry and Bio21 Institute , The University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Zhonghua Ren
- Chemical and Biomolecular Engineering , The University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Gabriel da Silva
- Chemical and Biomolecular Engineering , The University of Melbourne , Parkville , Victoria 3010 , Australia
| | - S Fern Lim
- School of Chemistry and Bio21 Institute , The University of Melbourne , Parkville , Victoria 3010 , Australia
| | - George N Khairallah
- School of Chemistry and Bio21 Institute , The University of Melbourne , Parkville , Victoria 3010 , Australia.,Accurate Mass Scientific Pty Ltd. , P.O. Box 92, Keilor VIC 3036 , Australia
| | - Michael J Rathjen
- School of Chemistry and Bio21 Institute , The University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Jonathan M White
- School of Chemistry and Bio21 Institute , The University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Institute , The University of Melbourne , Parkville , Victoria 3010 , Australia
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27
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Brydon SC, Lim SF, Khairallah GN, Maître P, Loire E, da Silva G, O'Hair RAJ, White JM. Reactions of Thiiranium and Sulfonium Ions with Alkenes in the Gas Phase. J Org Chem 2019; 84:10076-10087. [PMID: 31328517 DOI: 10.1021/acs.joc.9b01264] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ion-molecule reactions between thiiranium ion 11 (m/z 213) and cyclohexene and cis-cyclooctene resulted in the formation of addition products 17a and 17b (m/z 295 and m/z 323, respectively) via an electrophilic addition pathway. Associative π-ligand exchange involving direct transfer of the PhS+ moiety, which has been observed for analogous seleniranium ions in the gas phase, did not occur despite previous solution experiments suggesting it as a valid pathway. DFT calculations at the M06-2X/def2-TZVP level of theory showed high barriers for the exchange reaction, while the addition pathway was more plausible. Further support for this pathway was provided with Hammett plots showing the rate of reaction to increase as the benzylic position of thiiranium ion derivatives became more electrophilic (ρ = +1.69; R2 = 0.974). The more reactive isomeric sulfonium ion 22 was discounted as being responsible for the observed reactivity with infrared spectroscopy and DFT calculations suggesting little possibility for isomerization. To further explore the differences in reactivity, thiiranium ion 25 and sulfonium ion 27 were formed independently, with the latter ion reacting over 260 times faster toward cis-cyclooctene than the thiiranium ion rationalized by calculations suggesting a barrierless pathway for sulfonium ion 27 to react with the cycloalkene.
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Affiliation(s)
| | | | - George N Khairallah
- Accurate Mass Scientific Pty Ltd , P.O. Box 92, Keilor , VIC 3036 , Australia
| | - Philippe Maître
- Laboratoire de Chimie Physique (UMR8000), Université Paris-Sud, CNRS , Université Paris Saclay , Orsay 91405 , France
| | - Estelle Loire
- Laboratoire de Chimie Physique (UMR8000), Université Paris-Sud, CNRS , Université Paris Saclay , Orsay 91405 , France
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28
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Piacentino EL, Parker K, Gilbert TM, O'Hair RAJ, Ryzhov V. Role of Ligand in the Selective Production of Hydrogen from Formic Acid Catalysed by the Mononuclear Cationic Zinc Complexes [(L)Zn(H)] + (L=tpy, phen, and bpy). Chemistry 2019; 25:9959-9966. [PMID: 31090119 DOI: 10.1002/chem.201901360] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 04/25/2019] [Indexed: 11/10/2022]
Abstract
A series of zinc-based catalysts was evaluated for their efficiency in decomposing formic acid into molecular hydrogen and carbon dioxide in the gas phase using quadrupole ion trap mass spectrometry experiments. The effectiveness of the catalysts in the series [(L)Zn(H)]+ , where L=2,2':6',2''-terpyridine (tpy), 1,10-phenanthroline (phen) or 2,2'-bipyrydine (bpy), was found to depend on the ligand used, which turned out to be fundamental in tuning the catalytic properties of the zinc complex. Specifically, [(tpy)Zn(H)]+ displayed the fastest reaction with formic acid proceeding by dehydrogenation to produce the zinc formate complex [(tpy)Zn(O2 CH)]+ and H2 . The catalysts [(L)Zn(H)]+ are reformed by decarboxylating the zinc formate complexes [(L)Zn(O2 CH)]+ by collision-induced dissociation, which is the only reaction channel for each of the ligands used. The decarboxylation reaction was found to be reversible, since the zinc hydride complexes [(L)Zn(H)]+ react with carbon dioxide yielding the zinc formate complex. This reaction was again substantially faster for L=tpy than L=phen or bpy. The energetics and mechanisms of these processes were modelled using several levels of density functional theory (DFT) calculations. Experimental results are fully supported by the computational predictions.
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Affiliation(s)
- Elettra L Piacentino
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA
| | - Kevin Parker
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA
| | - Thomas M Gilbert
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Victor Ryzhov
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA
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29
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Piacentino EL, Rodriguez E, Parker K, Gilbert TM, O'Hair RAJ, Ryzhov V. Gas-phase functionalized carbon-carbon coupling reactions catalyzed by Ni (II) complexes. J Mass Spectrom 2019; 54:520-526. [PMID: 30989744 DOI: 10.1002/jms.4360] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 04/01/2019] [Accepted: 04/08/2019] [Indexed: 06/09/2023]
Abstract
Gas-phase C-C coupling reactions mediated by Ni (II) complexes were studied using a linear quadrupole ion trap mass spectrometer. Ternary nickel cationic carboxylate complexes, [(phen)Ni (OOCR1 )]+ (where phen = 1,10-phenanthroline), were formed by electrospray ionization. Upon collision-induced dissociation (CID), they extrude CO2 forming the organometallic cation [(phen)Ni(R1 )]+ , which undergoes gas-phase ion-molecule reactions (IMR) with acetate esters CH3 COOR2 to yield the acetate complex [(phen)Ni (OOCCH3 )]+ and a C-C coupling product R1 -R2 . These Ni(II)/phenanthroline-mediated coupling reactions can be performed with a variety of carbon substituents R1 and R2 (sp3 , sp2 , or aromatic), some of them functionalized. Reaction rates do not seem to be strongly dependent on the nature of the substituents, as sp3 -sp3 or sp2 -sp2 coupling reactions proceed rapidly. Experimental results are supported by density functional theory calculations, which provide insights into the energetics associated with the C-C bond coupling step.
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Affiliation(s)
- Elettra L Piacentino
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA
| | - Edwin Rodriguez
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA
| | - Kevin Parker
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA
| | - Thomas M Gilbert
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA
| | - Richard A J O'Hair
- Bio 21 Institute and School of Chemistry, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Victor Ryzhov
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA
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30
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O'Hair RAJ, Mravak A, Krstić M, Bonačić‐Koutecký V. Models Facilitating the Design of a New Metal‐Organic Framework Catalyst for the Selective Decomposition of Formic Acid into Hydrogen and Carbon Dioxide. ChemCatChem 2019. [DOI: 10.1002/cctc.201900799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Richard A. J. O'Hair
- School of Chemistry, and BIO21 Molecular Science, and Biotechnology InstituteThe University of Melbourne 30 Flemington Rd Parkville VIC 3010 Australia
| | - Antonija Mravak
- Center of Excellence for Science and Technology, – Integration of Mediterranean Region (STIM) at Interdisciplinary, Center for Advanced Sciences and Technology (ICAST)University of Split Poljička cesta 35 21000 Split Croatia
| | - Marjan Krstić
- Center of Excellence for Science and Technology, – Integration of Mediterranean Region (STIM) at Interdisciplinary, Center for Advanced Sciences and Technology (ICAST)University of Split Poljička cesta 35 21000 Split Croatia
| | - Vlasta Bonačić‐Koutecký
- Center of Excellence for Science and Technology, – Integration of Mediterranean Region (STIM) at Interdisciplinary, Center for Advanced Sciences and Technology (ICAST)University of Split Poljička cesta 35 21000 Split Croatia
- Chemistry DepartmentHumboldt University of Berlin Brook – Taylor – Strasse 2 12489 Berlin Germany
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31
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O'Hair RAJ, Mravak A, Krstić M, Bonačić‐Koutecký V. Front Cover: Models Facilitating the Design of a New Metal‐Organic Framework Catalyst for the Selective Decomposition of Formic Acid into Hydrogen and Carbon Dioxide (ChemCatChem 10/2019). ChemCatChem 2019. [DOI: 10.1002/cctc.201900798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Richard A. J. O'Hair
- School of Chemistry and BIO21 Molecular Science and Biotechnology InstituteThe University of Melbourne 30 Flemington Rd Parkville VIC 3010 Australia
| | - Antonija Mravak
- Center of Excellence for Science and Technology – Integration of Mediterranean Region (STIM) at Interdisciplinary Center for Advanced Sciences and Technology (ICAST)University of Split Poljička cesta 35 21000 Split Croatia
| | - Marjan Krstić
- Center of Excellence for Science and Technology – Integration of Mediterranean Region (STIM) at Interdisciplinary Center for Advanced Sciences and Technology (ICAST)University of Split Poljička cesta 35 21000 Split Croatia
| | - Vlasta Bonačić‐Koutecký
- Center of Excellence for Science and Technology – Integration of Mediterranean Region (STIM) at Interdisciplinary Center for Advanced Sciences and Technology (ICAST)University of Split Poljička cesta 35 21000 Split Croatia
- Chemistry DepartmentHumboldt University of Berlin Brook-Taylor-Strasse 2 12489 Berlin Germany
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32
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O'Hair RAJ, Mravak A, Krstić M, Bonačić‐Koutecký V. Models Facilitating the Design of a New Metal‐Organic Framework Catalyst for the Selective Decomposition of Formic Acid into Hydrogen and Carbon Dioxide. ChemCatChem 2019. [DOI: 10.1002/cctc.201900346] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Richard A. J. O'Hair
- School of Chemistry and BIO21 Molecular Science and Biotechnology Institute The University of Melbourne 30 Flemington Rd Parkville VIC 3010 Australia
| | - Antonija Mravak
- Center of Excellence for Science and Technology – Integration of Mediterranean Region (STIM) at Interdisciplinary Center for Advanced Sciences and Technology (ICAST) University of Split Poljička cesta 35 21000 Split Croatia
| | - Marjan Krstić
- Center of Excellence for Science and Technology – Integration of Mediterranean Region (STIM) at Interdisciplinary Center for Advanced Sciences and Technology (ICAST) University of Split Poljička cesta 35 21000 Split Croatia
| | - Vlasta Bonačić‐Koutecký
- Center of Excellence for Science and Technology – Integration of Mediterranean Region (STIM) at Interdisciplinary Center for Advanced Sciences and Technology (ICAST) University of Split Poljička cesta 35 21000 Split Croatia
- Chemistry Department Humboldt University of Berlin Brook-Taylor-Strasse 2 12489 Berlin Germany
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33
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34
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Weragoda GK, Pilkington RL, Polyzos A, O'Hair RAJ. Regioselectivity of aryl radical attack onto isocyanates and isothiocyanates. Org Biomol Chem 2018; 16:9011-9020. [PMID: 30427050 DOI: 10.1039/c8ob02209g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The combination of multistage mass spectrometry experiments employing the distonic radical approach together with DFT calculations are used to examine addition of the N-methyl-pyridinium-4-yl radical cation (γ-NMP) to iso(thio)cyanates in the gas-phase. The type of products formed depend on the nature of the iso(thio)cyanate: (1) hydrogen atom abstraction occurs for alkyl isocyanates; (2) aryl isocyanates undergo radical-ipso substitution; (3) radical attack occurs at the C[double bond, length as m-dash]C bond of allyl isocyanate; (4) radical attack occurs at the C[double bond, length as m-dash]S bond of isothiocyanates to generate S adducts of γ-NMP and isonitriles. DFT calculations provide insight into the reactivity differences of these heterocumulenes towards the electrophilic C-centered γ-distonic radical cations. Translation of these gas phase results to the solution phase were hampered by dominating radical recombination reactions which appear to be favoured over the radical-iso(thio)cyanate reactions.
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35
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Bathie FLB, Bowen CJ, Hutton CA, O'Hair RAJ. Unimolecular reactivity of organotrifluoroborate anions, RBF 3- , and their alkali metal cluster ions, M(RBF 3 ) 2- (M = Na, K; R = CH 3 , CH 3 CH 2 , CH 3 (CH 2 ) 3 , CH 3 (CH 2 ) 5 , c-C 3 H 5 , C 6 H 5 , C 6 H 5 CH 2 , CH 2 CHCH 2 , CH 2 CH, C 6 H 5 CO). Rapid Commun Mass Spectrom 2018; 32:1045-1052. [PMID: 29645303 DOI: 10.1002/rcm.8134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/22/2018] [Accepted: 03/25/2018] [Indexed: 06/08/2023]
Abstract
RATIONALE Potassium organotrifluoroborates (RBF3 K) are important reagents used in organic synthesis. Although mass spectrometry is commonly used to confirm their molecular formulae, the gas-phase fragmentation reactions of organotrifluoroborates and their alkali metal cluster ions have not been previously reported. METHODS Negative-ion mode electrospray ionization (ESI) together with collision-induced dissociation (CID) using a triple quadrupole mass spectrometer were used to examine the fragmentation pathways for RBF3- (where R = CH3 , CH3 CH2 , CH3 (CH2 )3 , CH3 (CH2 )5 , c-C3 H5 , C6 H5 , C6 H5 CH2 , CH2 CHCH2 , CH2 CH, C6 H5 CO) and M(RBF3 )2- (M = Na, K), while density functional theory (DFT) calculations at the M06/def2-TZVP level were used to examine the structures and energies associated with fragmentation reactions for R = Me and Ph. RESULTS Upon CID, preferentially elimination of HF occurs for RBF3- ions for systems where R = an alkyl anion, whereas R- formation is favoured when R = a stabilized anion. At higher collision energies loss of F- and additional HF losses are sometimes observed. Upon CID of M(RBF3 )2- , formation of RBF3- is the preferred pathway with some fluoride transfer observed only when M = Na. The DFT-calculated relative thermochemistry for competing fragmentation pathways is consistent with the experiments. CONCLUSIONS The main fragmentation pathways of RBF3- are HF elimination and/or R- loss. This contrasts with the fragmentation reactions of other organometallate anions, where reductive elimination, beta hydride transfer and bond homolysis are often observed. The presence of fluoride transfer upon CID of Na(RBF3 )2- but not K(RBF3 )2- is in agreement with the known fluoride affinities of Na+ and K+ and can be rationalized by Pearson's HSAB theory.
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Affiliation(s)
- Fiona L B Bathie
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Chris J Bowen
- Shimadzu Scientific, Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Craig A Hutton
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, Victoria, 3010, Australia
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36
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Weske S, Hardin RA, Auth T, O'Hair RAJ, Koszinowski K, Ogle CA. Argentate(i) and (iii) complexes as intermediates in silver-mediated cross-coupling reactions. Chem Commun (Camb) 2018; 54:5086-5089. [PMID: 29708564 DOI: 10.1039/c8cc01707g] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Despite the potential of silver to mediate synthetically valuable cross-coupling reactions, the operating mechanisms have remained unknown. Here, we use a combination of rapid-injection NMR spectroscopy, electrospray-ionization mass spectrometry, and quantum chemical calculations to demonstrate that these transformations involve argentate(i) and (iii) complexes as key intermediates.
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Affiliation(s)
- Sebastian Weske
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany.
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37
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Krstić M, Jin Q, Khairallah GN, O'Hair RAJ, Bonačić‐Koutecký V. How to Translate the [LCu
2
(H)]
+
‐Catalysed Selective Decomposition of Formic Acid into H
2
and CO
2
from the Gas Phase into a Zeolite. ChemCatChem 2018. [DOI: 10.1002/cctc.201701594] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marjan Krstić
- Center of excellence for science and technology—, integration of Mediterranean region (STIM) at, Interdisciplinary Center for Advanced Sciences and Technology (ICAST) University of Split Meštrovićevo Šetalište 45 21000 Split Croatia
| | - Qiuyan Jin
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute University of Melbourne 30 Flemington Rd Parkville Victoria 3010 Australia
| | - George N. Khairallah
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute University of Melbourne 30 Flemington Rd Parkville Victoria 3010 Australia
| | - Richard A. J. O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute University of Melbourne 30 Flemington Rd Parkville Victoria 3010 Australia
| | - Vlasta Bonačić‐Koutecký
- Center of excellence for science and technology—, integration of Mediterranean region (STIM) at, Interdisciplinary Center for Advanced Sciences and Technology (ICAST) University of Split Meštrovićevo Šetalište 45 21000 Split Croatia
- Chemistry Department Humboldt University of Berlin Brook-Taylor-Strasse 2 12489 Berlin Germany
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38
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Li J, Ma HZ, Reid GE, Edwards AJ, Hong Y, White JM, Mulder RJ, O'Hair RAJ. Synthesis and X‐Ray Crystallographic Characterisation of Frustum‐Shaped Ligated [Cu
18
H
16
(DPPE)
6
]
2+
and [Cu
16
H
14
(DPPA)
6
]
2+
Nanoclusters and Studies on Their H
2
Evolution Reactions. Chemistry 2018; 24:2070-2074. [DOI: 10.1002/chem.201705448] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Indexed: 12/26/2022]
Affiliation(s)
- Jiaye Li
- School of Chemistry and Bio21 Molecular Science, and Biotechnology Institute University of Melbourne 30 Flemington Rd Parkville, Victoria 3010 Australia
| | - Howard Z. Ma
- School of Chemistry and Bio21 Molecular Science, and Biotechnology Institute University of Melbourne 30 Flemington Rd Parkville, Victoria 3010 Australia
| | - Gavin E. Reid
- School of Chemistry and Bio21 Molecular Science, and Biotechnology Institute University of Melbourne 30 Flemington Rd Parkville, Victoria 3010 Australia
- Department of Biochemistry and Molecular Biology University of Melbourne 30 Flemington Rd Parkville, Victoria 3010 Australia
| | - Alison J. Edwards
- Australian Centre for Neutron Scattering Australian Nuclear Science and Technology Organisation New Illawarra Road Lucas Heights NSW 2234 Australia
| | - Yuning Hong
- School of Chemistry and Bio21 Molecular Science, and Biotechnology Institute University of Melbourne 30 Flemington Rd Parkville, Victoria 3010 Australia
| | - Jonathan M. White
- School of Chemistry and Bio21 Molecular Science, and Biotechnology Institute University of Melbourne 30 Flemington Rd Parkville, Victoria 3010 Australia
| | - Roger J. Mulder
- CSIRO Manufacturing Research Way Clayton, Victoria 3168 Australia
| | - Richard A. J. O'Hair
- School of Chemistry and Bio21 Molecular Science, and Biotechnology Institute University of Melbourne 30 Flemington Rd Parkville, Victoria 3010 Australia
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39
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Lesslie M, Yang Y, Canty AJ, Piacentino E, Berthias F, Maitre P, Ryzhov V, O'Hair RAJ. Ligand-induced decarbonylation in diphosphine-ligated palladium acetates [CH3CO2Pd((PR2)2CH2)]+ (R = Me and Ph). Chem Commun (Camb) 2018; 54:346-349. [DOI: 10.1039/c7cc08944a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Isotope labelling, IR spectroscopy and DFT calculations reveal a novel ligand-induced decarbonylation reaction.
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Affiliation(s)
- Michael Lesslie
- Department of Chemistry and Biochemistry
- and Center for Biochemical and Biophysical Sciences
- Northern Illinois University
- DeKalb
- USA
| | - Yang Yang
- School of Chemistry
- Bio21 Institute of Molecular Science and Biotechnology
- The University of Melbourne
- Victoria 3010
- Australia
| | - Allan J. Canty
- School of Physical Sciences
- University of Tasmania
- Hobart
- Australia
| | - Elettra Piacentino
- Department of Chemistry and Biochemistry
- and Center for Biochemical and Biophysical Sciences
- Northern Illinois University
- DeKalb
- USA
| | - Francis Berthias
- Laboratoire de Chimie Physique
- Bâtiment 349
- Université Paris-Sud
- CNRS
- Université Paris-Saclay
| | - Philippe Maitre
- Laboratoire de Chimie Physique
- Bâtiment 349
- Université Paris-Sud
- CNRS
- Université Paris-Saclay
| | - Victor Ryzhov
- Department of Chemistry and Biochemistry
- and Center for Biochemical and Biophysical Sciences
- Northern Illinois University
- DeKalb
- USA
| | - Richard A. J. O'Hair
- School of Chemistry
- Bio21 Institute of Molecular Science and Biotechnology
- The University of Melbourne
- Victoria 3010
- Australia
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40
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Ma HZ, White JM, Mulder RJ, Reid GE, Canty AJ, O'Hair RAJ. Synthesis, structure, and condensed-phase reactivity of [Ag3(μ3-H)(μ3-BH4)LPh3](BF4) (LPh = bis(diphenylphosphino)amine) with CS2. Dalton Trans 2018; 47:14713-14725. [DOI: 10.1039/c8dt02437e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electrospray ionisation mass spectrometry (ESI-MS) was used to monitor the reaction of AgBF4, bis(diphenylphosphino)amine (dppa = (Ph2P)2NH = LPh) and NaBH4 in acetonitrile.
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Affiliation(s)
- Howard Z. Ma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute
- University of Melbourne
- Parkville
- Australia
| | - Jonathan M. White
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute
- University of Melbourne
- Parkville
- Australia
| | | | - Gavin E. Reid
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute
- University of Melbourne
- Parkville
- Australia
- Department of Biochemistry and Molecular Biology
| | - Allan J. Canty
- School of Natural Sciences – Chemistry
- University of Tasmania
- Hobart
- Australia
| | - Richard A. J. O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute
- University of Melbourne
- Parkville
- Australia
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41
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Traylor MJ, Baek JM, Richards KE, Fusetto R, Huang W, Josh P, Chen Z, Bollapragada P, O'Hair RAJ, Batterham P, Gillam EMJ. Recombinant expression and characterization of Lucilia cuprina CYP6G3: Activity and binding properties toward multiple pesticides. Insect Biochem Mol Biol 2017; 90:14-22. [PMID: 28918158 DOI: 10.1016/j.ibmb.2017.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 09/08/2017] [Accepted: 09/10/2017] [Indexed: 06/07/2023]
Abstract
The Australian sheep blowfly, Lucilia cuprina, is a primary cause of sheep flystrike and a major agricultural pest. Cytochrome P450 enzymes have been implicated in the resistance of L. cuprina to several classes of insecticides. In particular, CYP6G3 is a L. cuprina homologue of Drosophila melanogaster CYP6G1, a P450 known to confer multi-pesticide resistance. To investigate the basis of resistance, a bicistronic Escherichia coli expression system was developed to co-express active L. cuprina CYP6G3 and house fly (Musca domestica) P450 reductase. Recombinant CYP6G3 showed activity towards the high-throughput screening substrates, 7-ethoxycoumarin and p-nitroanisole, but not towards p-nitrophenol, coumarin, 7-benzyloxyresorufin, or seven different luciferin derivatives (P450-Glo™ substrates). The addition of house fly cytochrome b5 enhanced the kcat for p-nitroanisole dealkylation approximately two fold (17.8 ± 0.5 vs 9.6 ± 0.2 min-1) with little effect on KM (13 ± 1 vs 10 ± 1 μM). Inhibition studies and difference spectroscopy revealed that the organochlorine compounds, DDT and endosulfan, and the organophosphate pesticides, malathion and chlorfenvinphos, bind to the active site of CYP6G3. All four pesticides showed type I binding spectra with spectral dissociation constants in the micromolar range suggesting that they may be substrates of CYP6G3. While no significant inhibition was seen with the organophosphate, diazinon, or the neonicotinoid, imidacloprid, diazinon showed weak binding in spectral assays, with a Kd value of 23 ± 3 μM CYP6G3 metabolised diazinon to the diazoxon and hydroxydiazinon metabolites and imidacloprid to the 5-hydroxy and olefin metabolites, consistent with a proposed role of CYP6G enzymes in metabolism of phosphorothioate and neonicotinoid insecticides in other species.
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Affiliation(s)
- Matthew J Traylor
- School of Chemistry and Molecular Biology, University of Queensland, St. Lucia 4072, Australia
| | - Jong-Min Baek
- School of Chemistry and Molecular Biology, University of Queensland, St. Lucia 4072, Australia
| | - Katelyn E Richards
- School of Chemistry and Molecular Biology, University of Queensland, St. Lucia 4072, Australia
| | - Roberto Fusetto
- The Bio21 Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - W Huang
- School of Chemistry and Molecular Biology, University of Queensland, St. Lucia 4072, Australia
| | - Peter Josh
- School of Chemistry and Molecular Biology, University of Queensland, St. Lucia 4072, Australia
| | - Zhenzhong Chen
- The Bio21 Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Padma Bollapragada
- School of Chemistry and Molecular Biology, University of Queensland, St. Lucia 4072, Australia
| | - Richard A J O'Hair
- The Bio21 Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Philip Batterham
- The Bio21 Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Elizabeth M J Gillam
- School of Chemistry and Molecular Biology, University of Queensland, St. Lucia 4072, Australia.
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42
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Fusetto R, Denecke S, Perry T, O'Hair RAJ, Batterham P. Partitioning the roles of CYP6G1 and gut microbes in the metabolism of the insecticide imidacloprid in Drosophila melanogaster. Sci Rep 2017; 7:11339. [PMID: 28900131 PMCID: PMC5595926 DOI: 10.1038/s41598-017-09800-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 07/28/2017] [Indexed: 11/09/2022] Open
Abstract
Resistance to insecticides through enhanced metabolism is a worldwide problem. The Cyp6g1 gene of the vinegar fly, Drosophila melanogaster, is a paradigm for the study of metabolic resistance. Constitutive overexpression of this gene confers resistance to several classes of insecticides, including the neonicotinoid imidacloprid (IMI). The metabolism of IMI in this species has been previously shown to yield oxidative and nitro-reduced metabolites. While levels of the oxidative metabolites are correlated with CYP6G1 expression, nitro-reduced metabolites are not, raising the question of how these metabolites are produced. Some IMI metabolites are known to be toxic, making their fate within the insect a second question of interest. These questions have been addressed by coupling the genetic tools of gene overexpression and CRISPR gene knock-out with the mass spectrometric technique, the Twin-Ion Method (TIM). Analysing axenic larvae indicated that microbes living within D. melanogaster are largely responsible for the production of the nitro-reduced metabolites. Knock-out of Cyp6g1 revealed functional redundancy, with some metabolites produced by CYP6G1 still detected. IMI metabolism was shown to produce toxic products that are not further metabolized but readily excreted, even when produced in the Central Nervous System (CNS), highlighting the significance of transport and excretion in metabolic resistance.
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Affiliation(s)
- Roberto Fusetto
- School of Chemistry, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Victoria, 3010, Australia.,School of Bioscience, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Shane Denecke
- School of Bioscience, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Trent Perry
- School of Bioscience, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Richard A J O'Hair
- School of Chemistry, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Philip Batterham
- School of Bioscience, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Victoria, 3010, Australia.
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43
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O'Hair RAJ. Focus Honoring Dr. Kristina "Kicki" Håkansson, Recipient of the 2016 Biemann Medal. J Am Soc Mass Spectrom 2017; 28:1739-1740. [PMID: 28748379 DOI: 10.1007/s13361-017-1729-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
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44
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Taggert BI, O'Hair RAJ, Wille U. Environmental Polymer Degradation: Using the Distonic Radical Ion Approach to Study the Gas-Phase Reactions of Model Polyester Radicals. J Phys Chem A 2017. [PMID: 28644629 DOI: 10.1021/acs.jpca.7b04217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel precursor to the distonic O- and C-centered radical cations Oxo+O• and Oxo+C• was designed and synthesized, which represents model systems for radicals produced during polyester degradation. The precursor is equipped with a nitrate functional group, which serves as a masked site for these alkoxyl and carbon radicals that are unleashed through collision-induced dissociation (CID). Oxo+O• and Oxo+C• feature a cyclic carboxonium ion as permanent charge tag to enable monitoring their ion-molecule reactions on the millisecond to second time scale in the ion trap of the mass spectrometer. The reactions of Oxo+O• and Oxo+C• with cyclohexene, cyclohexadiene, ethyl acetate, 1,1-dimethoxyethane, and 1,2-dimethoxyethane, which exhibit structural features present in both intact and defective polyesters, were explored through product and kinetic studies to identify "hot spots" for radical-induced damage in polyesters. All reactions with Oxo+O• were extremely fast and proceeded predominantly through HAT. Oxo+C• was about two orders of magnitude less reactive and did not noticeably damage aliphatic ester moieties through hydrogen abstraction on the time scale of our experiments. Radical addition to alkene π systems was identified as an important pathway for C-radicals, which needs to be included in polymer degradation mechanisms.
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Affiliation(s)
- Bethany I Taggert
- School of Chemistry, Bio21 Institute, The University of Melbourne , 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Richard A J O'Hair
- School of Chemistry, Bio21 Institute, The University of Melbourne , 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Uta Wille
- School of Chemistry, Bio21 Institute, The University of Melbourne , 30 Flemington Road, Parkville, Victoria 3010, Australia
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45
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Osburn S, Speciale G, Williams SJ, O'Hair RAJ. Gas-Phase Intercluster Thiyl-Radical Induced C-H Bond Homolysis Selectively Forms Sugar C2-Radical Cations of Methyl D-Glucopyranoside: Isotopic Labeling Studies and Cleavage Reactions. J Am Soc Mass Spectrom 2017; 28:1425-1431. [PMID: 28474266 DOI: 10.1007/s13361-017-1667-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 03/22/2017] [Accepted: 03/22/2017] [Indexed: 06/07/2023]
Abstract
A suite of isotopologues of methyl D-glucopyranosides is used in conjunction with multistage mass spectrometry experiments to determine the radical site and cleavage reactions of sugar radical cations formed via a recently developed 'bio-inspired' method. In the first stage of CID (MS2), collision-induced dissociation (CID) of a protonated noncovalent complex between the sugar and S-nitrosocysteamine, [H3NCH2CH2SNO + M]+, unleashes a thiyl radical via bond homolysis to give the noncovalent radical cation, [H3NCH2CH2S• + M]+. CID (MS3) of this radical cation complex results in dissociation of the noncovalent complex to generate the sugar radical cation. Replacement of all exchangeable OH and NH protons with deuterons reveals that the sugar radical cation is formed in a process involving abstraction of a hydrogen atom from a C-H bond of the sugar coupled with proton transfer to the sugar, to form [M - H• + D+]. Investigation of this process using individual C-D labeled sugars reveals that the main site of H/D abstraction is the C2 position, since only the C2-deuterium labeled sugar yields a dominant [M - D• + H+] product ion. The fragmentation reactions of the distonic sugar radical cation, [M - H•+ H+], were studied by another stage of CID (MS4). 13C-labeling studies revealed that a series of three related fragment ions each contain the C1-C3 atoms; these arise from cross-ring cleavage reactions of the sugar. Graphical Abstract ᅟ.
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Affiliation(s)
- Sandra Osburn
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
- ARC Center of Excellence for Free Radical Chemistry and Biotechnology, The University of Melbourne, Victoria, 3010, Australia
| | - Gaetano Speciale
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - Spencer J Williams
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia.
- ARC Center of Excellence for Free Radical Chemistry and Biotechnology, The University of Melbourne, Victoria, 3010, Australia.
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46
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Lim SF, Harris BL, Khairallah GN, Bieske EJ, Maître P, da Silva G, Adamson BD, Scholz MS, Coughlan NJA, O'Hair RAJ, Rathjen M, Stares D, White JM. Seleniranium Ions Undergo π-Ligand Exchange via an Associative Mechanism in the Gas Phase. J Org Chem 2017; 82:6289-6297. [PMID: 28530810 DOI: 10.1021/acs.joc.7b00877] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Collision-induced dissociation mass spectrometry of the ammonium ions 4a and 4b results in the formation of the seleniranium ion 5, the structure and purity of which were verified using gas-phase infrared spectroscopy coupled to mass spectrometry and gas-phase ion-mobility measurements. Ion-molecule reactions between the ion 5 (m/z = 261) and cyclopentene, cyclohexene, cycloheptene, and cyclooctene resulted in the formation of the seleniranium ions 7 (m/z = 225), 6 (m/z = 239), 8 (m/z = 253), and 9 (m/z = 267), respectively. Further reaction of seleniranium 6 with cyclopentene resulted in further π-ligand exchange giving seleniranium ion 7, confirming that direct π-ligand exchange between seleniranium ion 5 and cycloalkenes occurs in the gas phase. Pseudo-first-order kinetics established relative reaction efficiencies for π-ligand exchange for cyclopentene, cyclohexene, cycloheptene. and cyclooctene as 0.20, 0.07, 0.43, and 4.32. respectively. DFT calculations at the M06/6-31+G(d) level of theory provide the following insights into the mechanism of the π-ligand exchange reactions; the cycloalkene forms a complex with the seleniranium ion 5 with binding energies of 57 and 62 kJ/mol for cyclopentene and cyclohexene, respectively, with transition states for π-ligand exchange having barriers of 17.8 and 19.3 kJ/mol for cyclopentene and cyclohexene, respectively.
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Affiliation(s)
- S Fern Lim
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Benjamin L Harris
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - George N Khairallah
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia.,Accurate Mass Scientific Pty Ltd., P.O. Box 92, Keilor, VIC 3036, Australia
| | - E J Bieske
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Philippe Maître
- Laboratoire de Chimie Physique, Université Paris-Sud, CNRS, Université Paris-Saclay , F-91405 Orsay, France
| | - Gabriel da Silva
- Chemical and Biomolecular Engineering, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Brian D Adamson
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Michael S Scholz
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Neville J A Coughlan
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Michael Rathjen
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Daniel Stares
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Jonathan M White
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
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47
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Abstract
Metabolic bioactivation of many different chemicals results in the formation of highly reactive compounds (chemically reactive metabolites, CRMs) that can lead to toxicity via binding to macromolecular targets (e.g., proteins or DNA). There is a need to develop robust, rapid, and nontargeted analytical techniques to determine the identity of the protein targets of CRMs and their sites of modification. Here, we introduce a nontargeted methodology capable of determining both the identity of a CRM formed from an administered compound as well as the protein targets modified by the reactive metabolite in a single experiment without prior information. Acetaminophen (N-acetyl-p-aminophenol, APAP) and 13C6-APAP were incubated with rat liver microsomes, which are known to bioactivate APAP to the reactive metabolite N-acetyl-p-benzoquinone imine (NAPQI). Global tryptic digestion followed by liquid chromatographic/mass spectrometric (LC/MS) analysis was used to locate "twin" ion peaks of peptides adducted by NAPQI and for shotgun proteomics via tandem mass spectrometry (MS/MS). By the development of blended data analytics software called Xenophile, the identity of the amino acid residue that was adducted can be established, which eliminates the need for specific parametrization of protein database search algorithms. This combination of experimental design and data analysis software allows the identity of a CRM, the protein target, and the amino acid residues that are modified to be rapidly established directly from experimental data. Xenophile is freely available from https://github.com/mgleeming/Xenophile .
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Affiliation(s)
- Michael G Leeming
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne , Melbourne, Victoria 3010, Australia
| | - William A Donald
- School of Chemistry, University of New South Wales , Sydney, New South Wales 2052, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne , Melbourne, Victoria 3010, Australia
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48
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Noor A, Li J, Khairallah GN, Li Z, Ghari H, Canty AJ, Ariafard A, Donnelly PS, O'Hair RAJ. A one-pot route to thioamides discovered by gas-phase studies: palladium-mediated CO 2 extrusion followed by insertion of isothiocyanates. Chem Commun (Camb) 2017; 53:3854-3857. [PMID: 28317056 DOI: 10.1039/c7cc00865a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new palladium mediated "one pot" synthesis of thioamides from aromatic carboxylic acids (ArCO2H + RNCS → ArC(S)NHR + CO2) was discovered by gas-phase experiments and theoretical studies. Palladium-mediated decarboxylation of aromatic carboxylic acids followed by addition of substituted isothiocyanates leads to the corresponding thioamide derivatives.
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Affiliation(s)
- Asif Noor
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia.
| | - Jiawei Li
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia.
| | - George N Khairallah
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia.
| | - Zhen Li
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia.
| | - Hossein Ghari
- Department of Chemistry, Faculty of Science, Central Tehran Branch, Islamic Azad University, Shahrak Gharb, Tehran, Iran.
| | - Allan J Canty
- School of Physical Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Alireza Ariafard
- Department of Chemistry, Faculty of Science, Central Tehran Branch, Islamic Azad University, Shahrak Gharb, Tehran, Iran.
| | - Paul S Donnelly
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia.
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia.
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49
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Zavras A, Krstić M, Dugourd P, Bonačić‐Koutecký V, O'Hair RAJ. Selectivity Effects in Bimetallic Catalysis: Role of the Metal Sites in the Decomposition of Formic Acid into H
2
and CO
2
by the Coinage Metal Binuclear Complexes [dppmMM′(H)]
+. ChemCatChem 2017. [DOI: 10.1002/cctc.201601675] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Athanasios Zavras
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute University of Melbourne 30 Flemington Rd Parkville, Victoria 3010 Australia
| | - Marjan Krstić
- Center of Excellence for Science and Technology, Integration of Mediterranean Region (STIM) at Interdisciplinary, Center for Advanced Sciences and Technology (ICAST) University of Split Meštrovićevo Šetalište 45 21000 Split Croatia
| | - Philippe Dugourd
- Institut Lumière Matière, CNRS Univ Lyon Université Claude Bernard Lyon 1 F-69622 Lyon France
| | - Vlasta Bonačić‐Koutecký
- Center of Excellence for Science and Technology, Integration of Mediterranean Region (STIM) at Interdisciplinary, Center for Advanced Sciences and Technology (ICAST) University of Split Meštrovićevo Šetalište 45 21000 Split Croatia
- Chemistry Department Humboldt University of Berlin Brook-Taylor-Strasse 2 12489 Berlin Germany
| | - Richard A. J. O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute University of Melbourne 30 Flemington Rd Parkville, Victoria 3010 Australia
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50
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Spillane S, Sharma R, Zavras A, Mulder R, Ohlin CA, Goerigk L, O'Hair RAJ, Ritchie C. Non‐Aqueous Microwave‐Assisted Syntheses of Deca‐ and Hexa‐Molybdovanadates. Angew Chem Int Ed Engl 2017; 56:8568-8572. [DOI: 10.1002/anie.201608589] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 11/23/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Samuel Spillane
- School of Chemistry The University of Melbourne Parkville Melbourne Victoria 3010 Australia
| | - Rupali Sharma
- School of Chemistry Monash University Victoria Australia
| | - Athanasios Zavras
- School of Chemistry The University of Melbourne Parkville Melbourne Victoria 3010 Australia
| | - Roger Mulder
- CSIRO Manufacturing Bayview Avenue Clayton Victoria 3168 Australia
| | - C. André Ohlin
- School of Chemistry Monash University Victoria Australia
- Department of Chemistry, Umeå University, Sweden
| | - Lars Goerigk
- School of Chemistry The University of Melbourne Parkville Melbourne Victoria 3010 Australia
| | - Richard A. J. O'Hair
- School of Chemistry The University of Melbourne Parkville Melbourne Victoria 3010 Australia
| | - Chris Ritchie
- School of Chemistry The University of Melbourne Parkville Melbourne Victoria 3010 Australia
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