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Runacres DE, Greenacre VK, Dyke JM, Grigg J, Herbert G, Levason W, McRobbie G, Reid G. Correction to "Synthesis, Characterization, and Computational Studies on Gallium(III) and Iron(III) Complexes with a Pentadentate Macrocyclic bis-Phosphinate Chelator and Their Investigation As Molecular Scaffolds for 18F Binding". Inorg Chem 2024; 63:2310. [PMID: 38237557 PMCID: PMC10828981 DOI: 10.1021/acs.inorgchem.3c04499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Indexed: 01/30/2024]
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Runacres D, Greenacre VK, Dyke JM, Grigg J, Herbert G, Levason W, McRobbie G, Reid G. Synthesis, Characterization, and Computational Studies on Gallium(III) and Iron(III) Complexes with a Pentadentate Macrocyclic bis-Phosphinate Chelator and Their Investigation As Molecular Scaffolds for 18F Binding. Inorg Chem 2023; 62:20844-20857. [PMID: 38055373 PMCID: PMC10731642 DOI: 10.1021/acs.inorgchem.3c03135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 11/10/2023] [Accepted: 11/10/2023] [Indexed: 12/08/2023]
Abstract
With the aim of obtaining improved molecular scaffolds for 18F binding to use in PET imaging, gallium(III) and iron(III) complexes with a macrocyclic bis-phosphinate chelator have been synthesized and their properties, including their fluoride binding ability, investigated. Reaction of Bn-tacn (1-benzyl-1,4,7-triazacyclononane) with paraformaldehyde and PhP(OR)2 (R = Me or Et) in refluxing THF, followed by acid hydrolysis, yields the macrocyclic bis(phosphinic acid) derivative, H2(Bn-NODP) (1-benzyl-4,7-phenylphosphinic acid-1,4,7-triazacyclononane), which is isolated as its protonated form, H2(Bn-NODP)·2HCl·4H2O, at low pH (HClaq), its disodium salt, Na2(Bn-NODP)·5H2O at pH 12 (NaOHaq), or the neutral H2(Bn-NODP) under mildly basic conditions (Et3N). A crystal structure of H2(Bn-NODP)·2HCl·H2O confirmed the ligand's identity. The mononuclear [GaCl(Bn-NODP)] complex was prepared by treatment of either the HCl or sodium salt with Ga(NO3)3·9H2O or GaCl3, while treatment of H2(Bn-NODP)·2HCl·4H2O with FeCl3 in aqueous HCl gives [FeCl(Bn-NODP)]. The addition of 1 mol. equiv of aqueous KF to these chloro complexes readily forms the [MF(Bn-NODP)] analogues. Spectroscopic analysis on these complexes confirms pentadentate coordination of the doubly deprotonated (bis-phosphinate) macrocycle via its N3O2 donor set, with the halide ligand completing a distorted octahedral geometry; this is further confirmed through a crystal structure analysis on [GaF(Bn-NODP)]·4H2O. The complex adopts the geometric isomer in which the phosphinate arms are coordinated unsymmetrically (isomer 1) and with the stereochemistry of the three N atoms of the tacn ring in the RRS configuration, denoted (N)RRS, and the phosphinate groups in the RR stereochemistry, denoted (P)RR, (isomer 1/RR), together with its (N)SSR (P)SS enantiomer. The greater thermodynamic stability of isomer 1/RR over the other possible isomers is also indicated by density functional theory (DFT) calculations. Radiofluorination experiments on the [MCl(Bn-NODP)] complexes in partially aqueous MeCN/NaOAcaq (Ga) or EtOH (Ga or Fe; i.e. without buffer) with 18F- target water at 80 °C/10 min lead to high radiochemical incorporation (radiochemical yields 60-80% at 1 mg/mL, or ∼1.5 μM, concentration of the precursor). While the [Fe18F(n-NODP)] is unstable (loss of 18F-) in both H2O/EtOH and PBS/EtOH (PBS = phosphate buffered saline), the [Ga18F(Bn-NODP)] radioproduct shows excellent stability, RCP = 99% at t = 4 h (RCP = radiochemical purity) when formulated in 90%:10% H2O/EtOH and ca. 95% RCP over 4 h when formulated in 90%:10% PBS/EtOH. This indicates that the new "GaIII(Bn-NODP)" moiety is a considerably superior fluoride binding scaffold than the previously reported [Ga18F(Bn-NODA)] (Bn-NODA = 1-benzyl-4,7-dicarboxylate-1,4,7-triazacyclononane), which undergoes rapid and complete hydrolysis in PBS/EtOH (refer to Chem. Eur. J. 2015, 21, 4688-4694).
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Affiliation(s)
- Danielle
E. Runacres
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Victoria K. Greenacre
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - John M. Dyke
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Julian Grigg
- GE
HealthCare, Pollards Wood, Nightingales Lane, Chalfont
St. Giles, Buckinghamshire HP8 4SP, United Kingdom
| | - George Herbert
- GE
HealthCare, Pollards Wood, Nightingales Lane, Chalfont
St. Giles, Buckinghamshire HP8 4SP, United Kingdom
| | - William Levason
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Graeme McRobbie
- GE
HealthCare, Pollards Wood, Nightingales Lane, Chalfont
St. Giles, Buckinghamshire HP8 4SP, United Kingdom
| | - Gillian Reid
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
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Rhyman L, Lee EPF, Ramasami P, Dyke JM. A study of the thermodynamics and mechanisms of the atmospherically relevant reaction dimethyl sulphide (DMS) with atomic chlorine (Cl) in the absence and presence of water, using electronic structure methods. Phys Chem Chem Phys 2023; 25:4780-4793. [PMID: 36692209 DOI: 10.1039/d2cp05814f] [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: 01/19/2023]
Abstract
The thermodynamics and mechanisms of the atmospherically relevant reaction dimethyl sulphide (DMS) + atomic chlorine (Cl) were investigated in the absence and presence of a single water molecule, using electronic structure methods. Stationary points on each reaction surface were located using density functional theory (DFT) with the M06-2X functional with aug-cc-pVDZ (aVDZ) and aug-cc-pVTZ (aVTZ) basis sets. Then fixed point calculations were carried out using the UM06-2X/aVTZ optimised stationary point geometries, with aug-cc-pVnZ basis sets (n = T and Q), using the coupled cluster method [CCSD(T)], as well as the domain-based local pair natural orbitals coupled cluster [DLPNO-UCCSD(T)] approach. Four reaction channels are possible, formation of (A) CH3SCH2 + HCl, (B) CH3S + CH3Cl, (C) CH3SCl + CH3, and (C') CH3S(Cl)CH3. The results show that, in the absence of water, channels A and C' are the dominant channels. In the presence of water, the calculations show that the reaction mechanisms for A and C formation change significantly. Channel A occurs via submerged TSs and is expected to be rapid. Channel B occurs via TSs which present significant energy barriers indicating that this channel is not significant in the presence of water relative to CH3SCH2 + HCl and DMS·Cl adduct formation, as is the case in the absence of water. Channel C was not considered as it is endothermic in the absence of water. In the presence of water, pathways which proceed via (a) DMS·H2O + Cl, (b) Cl·H2O + DMS and (c) DMS·Cl + H2O were considered. It was found that under tropospheric conditions, reactions via pathway (b) are of minor importance relative to those that proceed via pathways (a) and (c). This study has shown that water changes the mechanisms of the DMS + Cl reactions significantly but the presence of water is not expected to affect the overall reaction rate coefficient under atmospheric conditions as the DMS + Cl reaction has a rate coefficient at room temperature close to the collisional limit.
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Affiliation(s)
- Lydia Rhyman
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, 80837, Mauritius. .,Centre For Natural Product Research, Department of Chemical Sciences, University of Johannesburg, Doornfontein, Johannesburg, 2028, South Africa
| | - Edmond P F Lee
- School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
| | - Ponnadurai Ramasami
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, 80837, Mauritius. .,Centre For Natural Product Research, Department of Chemical Sciences, University of Johannesburg, Doornfontein, Johannesburg, 2028, South Africa
| | - John M Dyke
- School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
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King RP, Dyke JM, Levason W, Reid G. Neutral and Cationic Complexes of Silicon(IV) Halides with Phosphine Ligands. Inorg Chem 2022; 61:16905-16913. [PMID: 36222839 PMCID: PMC9597660 DOI: 10.1021/acs.inorgchem.2c02949] [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] [Indexed: 11/21/2022]
Abstract
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The reaction of SiI4 and PMe3 in n-hexane produced the yellow salt, [SiI3(PMe3)2]I, confirmed from its X-ray structure, containing
a trigonal bipyramidal cation with trans-phosphines.
This contrasts with the six-coordination found in (the known) trans-[SiX4(PMe3)2] (X
= Cl, Br) complexes. The diphosphines o-C6H4(PMe2)2 and Et2P(CH2)2PEt2 form six-coordinate cis-[SiI4(diphosphine)], which were also characterized by
X-ray crystallography, multinuclear NMR, and IR spectroscopy. Reaction
of trans-[SiX4(PMe3)2] (X = Cl, Br) with Na[BArF] (BArF = [B{3,5-(CF3)2C6H3}4]) produced
five-coordinate [SiX3(PMe3)2][BArF], but while Me3SiO3SCF3 also
abstracted chloride from trans-[SiCl4(PMe3)2], the reaction products were six-coordinate
complexes [SiCl3(PMe3)2(OTf)] and
[SiCl2(PMe3)2(OTf)2] with
the triflate coordinated. X-ray crystal structures were obtained for
[SiCl3(PMe3)2][BArF] and
[SiCl2(PMe3)2(OTf)2].
The charge distribution across the silicon species was also examined
by natural bond orbital (NBO) analyses of the computed density functional
theory (DFT) wavefunctions. For the [SiX4(PMe3)2] and [SiX3(PMe3)2]+ complexes, the positive charge on Si decreases and the negative
charge on X decreases going from X = F to X = I. Upon going from [SiX4(PMe3)2] to [SiX3(PMe3)2]+, i.e., removal of X–, there is an increase in positive charge on Si and a decrease in
negative charge on the X centers (except for the case X = F). The
positive charge on P shows a slight decrease. Unusual neutral and monocationic silicon(IV)
iodide complexes
with soft phosphine coordination are formed in hydrocarbon solvents,
while treatment of [SiCl4(PMe3)2]
with NaBArF forms the [SiCl3(PMe3)2]+ cation; the electronic structures of [SiX4(PMe3)2] and [SiX3(PMe3)2]+ (X = F, Cl, Br, I) are probed using
DFT calculations.
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Affiliation(s)
- Rhys P King
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
| | - John M Dyke
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
| | - William Levason
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
| | - Gillian Reid
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
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Olsson E, Ayari T, Ideböhn V, Wallner M, Squibb RJ, Andersson J, Roos AH, Stranges S, Dyke JM, Eland JHD, Hochlaf M, Feifel R. An experimental and theoretical characterization of the electronic structure of doubly ionised disulfur. Sci Rep 2022; 12:12236. [PMID: 35851404 PMCID: PMC9293938 DOI: 10.1038/s41598-022-16327-8] [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: 06/05/2022] [Accepted: 07/08/2022] [Indexed: 12/05/2022] Open
Abstract
Using time-of-flight multiple electron and ion coincidence techniques in combination with a helium gas discharge lamp and synchrotron radiation, the double ionisation spectrum of disulfur (S\documentclass[12pt]{minimal}
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\begin{document}$$_2$$\end{document}2) and the subsequent fragmentation dynamics of its dication are investigated. The S\documentclass[12pt]{minimal}
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\begin{document}$$_2$$\end{document}2 sample was produced by heating mercury sulfide (HgS), whose vapour at a suitably chosen temperature consists primarily of two constituents: S\documentclass[12pt]{minimal}
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\begin{document}$$_2$$\end{document}2 and atomic Hg. A multi-particle-coincidence technique is thus particularly useful for retrieving spectra of S\documentclass[12pt]{minimal}
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\begin{document}$$_2$$\end{document}2 from ionisation of the mixed vapour. The results obtained are compared with detailed calculations of the electronic structure and potential energy curves of S\documentclass[12pt]{minimal}
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\begin{document}$$_2^{2+}$$\end{document}22+ which are also presented. These computations are carried out using configuration interaction methodology. The experimental results are interpreted with and strongly supported by the computational results.
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Affiliation(s)
- Emelie Olsson
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58, Gothenburg, Sweden
| | - Tarek Ayari
- Université Gustave Eiffel, COSYS/IMSE, 5 Bd Descartes, 77454, Champs sur Marne, France
| | - Veronica Ideböhn
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58, Gothenburg, Sweden
| | - Måns Wallner
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58, Gothenburg, Sweden
| | - Richard J Squibb
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58, Gothenburg, Sweden
| | - Jonas Andersson
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58, Gothenburg, Sweden
| | - Andreas Hult Roos
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58, Gothenburg, Sweden.,ELI Beamlines, Institute of Physics AS CR, v.v.i., Na Slovance 2, 182 21, Prague 8, Czech Republic
| | - Stefano Stranges
- IOM-CNR Tasc, SS-14, Km 163.5 Area Science Park Basovizza, 34149, Trieste, Italy.,Dipartimento di Chimica e Tecnologie del Farmaco, Universitá Sapienza, 00185, Rome, Italy
| | - John M Dyke
- School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
| | - John H D Eland
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, UK
| | - Majdi Hochlaf
- Université Gustave Eiffel, COSYS/IMSE, 5 Bd Descartes, 77454, Champs sur Marne, France.
| | - Raimund Feifel
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58, Gothenburg, Sweden.
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Ideböhn V, Sterling AJ, Wallner M, Olsson E, Squibb RJ, Miniotaite U, Forsmalm E, Forsmalm M, Stranges S, Dyke JM, Duarte F, Eland JHD, Feifel R. Single photon double and triple ionization of allene. Phys Chem Chem Phys 2022; 24:786-796. [PMID: 34927639 DOI: 10.1039/d1cp04666g] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Double and triple ionization of allene are investigated using electron-electron, ion-ion, electron-electron-ion and electron-electron-ion-ion (ee, ii, eei, eeii) coincidence spectroscopies at selected photon energies. The results provide supporting evidence for a previously proposed roaming mechanism in H3+ formation by double ionization. The lowest vertical double ionization energy is found to be 27.9 eV, while adiabatic double ionization is not accessed by vertical ionization at the neutral geometry. The triple ionization energy is found to be close to 50 eV in agreement with theoretical predictions. The doubly charged parent ion is stable up to about 2 eV above the threshold, after which dissociations by charge separation and by double charge retention occur with comparable intensities. Fragmentation to H+ + C3H3+ starts immediately above the threshold as a slow (metastable) decay with 130.5 ± 9.9 ns mean lifetime.
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Affiliation(s)
- Veronica Ideböhn
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58 Gothenburg, Sweden.
| | - Alistair J Sterling
- Department of Chemistry, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK
| | - Måns Wallner
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58 Gothenburg, Sweden.
| | - Emelie Olsson
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58 Gothenburg, Sweden.
| | - Richard J Squibb
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58 Gothenburg, Sweden.
| | - Ugne Miniotaite
- Department of Physics, Chalmers University of Technology, Kemigården 1, 412 96 Gothenburg, Sweden
| | - Emma Forsmalm
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58 Gothenburg, Sweden.
| | - Malin Forsmalm
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58 Gothenburg, Sweden.
| | - Stefano Stranges
- IOM-CNR Tasc, SS-14, Km 163.5 Area Science Park, Basovizza 34149, Trieste, Italy.,Dipartimento di Chimica e Tecnologie del Farmaco, Universitá Sapienza, Rome I-00185, Italy
| | - John M Dyke
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Fernanda Duarte
- Department of Chemistry, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK
| | - John H D Eland
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, UK
| | - Raimund Feifel
- Department of Physics, University of Gothenburg, Origovägen 6B, 412 58 Gothenburg, Sweden.
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King RP, Greenacre VK, Levason W, Dyke JM, Reid G. Pyramidal Dicationic Ge(II) Complexes with Homoleptic Neutral Pnictine Coordination: A Combined Experimental and Density Functional Theory Study. Inorg Chem 2021; 60:12100-12108. [PMID: 34319096 DOI: 10.1021/acs.inorgchem.1c01308] [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: 11/29/2022]
Abstract
An unusual series of Ge(II) dicationic species with homoleptic phosphine and arsine coordination, [Ge(L)][OTf]2, L = 3 × PMe3, triphos (MeC(CH2PPh2)3), triars (MeC(CH2AsMe2)3), or κ3-tetraphos (P(CH2CH2PPh2)3) (OTf- = O3SCF3-) have been prepared by reaction of [GeCl2(dioxane)] with L and 2 mol equiv of Me3SiOTf in anhydrous CH2Cl2 (or MeCN for L = triars, triphos). X-ray crystal structures are reported for [Ge(PMe3)3][OTf]2, [Ge(triars)][OTf]2, and [Ge(κ3-tetraphos)][OTf]2, confirming homoleptic P3- or As3-coordination at Ge(II) in each case and with the discrete OTf- anions providing a charge balance. The Ge-P/As bond lengths are significantly shorter than those in neutral germanium(II) dihalide complexes with diphosphine or diarsine coordination. Solution NMR spectroscopic data indicate that the complexes are labile in solution. Using excess AsMe3 and [GeCl2(dioxane)] gives only the neutral product, [Ge(AsMe2)2(OTf)2], the crystal structure of which shows four coordination at Ge(II), via two As donor atoms and an O atom from two κ1-OTf- ligands; further weak, long-range intermolecular interactions give a chain polymer. The electronic structure of the [Ge(PMe3)3]2+ dication has been investigated using density functional theory (DFT) calculations. The computed geometrical parameters for this dication are in good agreement with the experimental X-ray crystallographic values in [Ge(PMe3)3][OTf]2. The results also indicate that the pyramidal arrangement of the [Ge(PMe3)3]2+ (computed P-Ge-P angle 96.8° at the B3LYP-D3 level) arises from a balance between electronic energy (Eelec) contributions, which favor a lower P-Ge-P angle, and nuclear-nuclear contributions (Enn), which favor a higher P-Ge-P angle, to the total energy (ETOT). An Atoms in Molecules (AIM) analysis reveals that one reason why Eelec decreases as the P-Ge-P angle decreases is because of C···H and H···H interactions between atoms on different CH3 groups. The stability of the [Ge(PMe3)3]2+ dication is enhanced by the distribution of a significant part of the positive charge on Ge2+ to the atomic centers of the PMe3 ligands. Similar results were obtained for [Ge(AsMe3)3][OTf]2, showing the tris-AsMe3 complex to be less stable compared to the PMe3 analogue. Related calculations were also performed for the neutral [Ge(PMe3)2(OTf)2] and [Ge(AsMe3)2(OTf)2] complexes.
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Affiliation(s)
- Rhys P King
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | | | - William Levason
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | - John M Dyke
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | - Gillian Reid
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
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Chow R, Mok DKW, Lee EPF, Dyke JM. Comment on "Impact of water on the BrO + HO 2 gas-phase reaction: mechanism, kinetics and products" by N. T. Tsona, S. Tang and L. Du, Phys. Chem. Chem. Phys., 2019, 21, 20296. Phys Chem Chem Phys 2021; 23:6309-6315. [PMID: 33735337 DOI: 10.1039/d0cp00222d] [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
The reaction, BrO + HO2 → HOBr + O2, is exothermic and can produce O2 in both its ground state (X[combining tilde]3∑g-) and its first excited state (ã1Δg). As a result, this reaction can proceed on both a singlet and a triplet potential energy surface. Recently, Tsona, Tang and Du published a paper entitled "Impact of water on the BrO + HO2 gas-phase reaction: mechanism, kinetics and products (Phys. Chem. Chem. Phys. 2019, 21, 20296-203072). The results of this work showed significant differences from those published earlier on this reaction by Chow et al. (Phys. Chem. Chem. Phys. 2016, 18, 30554-30569). Further calculations performed in this present work, combined with higher level calculations published by Chow et al. (Phys. Chem. Chem. Phys. 2016, 18, 30554-30569), demonstrate that the work of Tsona et al. is flawed because the integration grid size used in their lowest singlet and triplet calculations is too small, and a closed-shell wavefunction, rather than an open-shell wavefunction, has been used for the singlet surface. The major conclusion in the work of Tsona et al. that the lowest singlet and triplet channels are barrierless is shown to be incorrect. Also, the computed rate coefficients of Tsona et al. showed a positive temperature dependence, which is inconsistent with the experimentally observed negative temperature dependence, whereas the singlet rate coefficients computed by Chow et al. (Phys. Chem. Chem. Phys. 2016, 18, 30554-30569) showed a negative temperature dependence consistent with experiment.
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Affiliation(s)
- Ronald Chow
- Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong.
| | - Daniel K W Mok
- Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong.
| | - Edmond P F Lee
- Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong. .,School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - John M Dyke
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
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Laurent CM, Dyke JM, Cook RB, Dyke G, de Kat R. Spectroscopy on the wing: Investigating possible differences in protein secondary structures in feather shafts of birds using Raman spectroscopy. J Struct Biol 2020; 211:107529. [PMID: 32416130 DOI: 10.1016/j.jsb.2020.107529] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/24/2020] [Accepted: 05/03/2020] [Indexed: 10/24/2022]
Abstract
The central shaft of a bird's flight feather bears most of the aerodynamic load during flight and exhibits some remarkable mechanical properties. The shaft comprises two parts, the calamus and the rachis. The calamus is at the base of the shaft, while the rachis is the longer upper part which supports the vanes. The shaft is composed of a fibrous outer cortex, and an inner foam-like core. Recent nanoindentation experiments have indicated that reduced modulus values, Er, for the inner and outer regions of the cortex can vary, with the Er values of the inner region slightly greater than those of the outer region. In this work, Raman spectroscopy is used to investigate the protein secondary structures in the inner and outer regions of the feather cortex. Analysis of the Amide I region of Raman spectra taken from four birds (Swan, Gull, Mallard and Kestrel) shows that the β-sheet structural component decreases between the inner and outer region, relative to the protein side-chain components. This finding is consistent with the proposal that Er values are greater in the inner region than the outer region. This work has shown that Raman spectroscopy can be used effectively to study the change in protein secondary structure between the inner and outer regions of a feather shaft.
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Affiliation(s)
- Christian M Laurent
- Aerodynamics and Flight Mechanics, University of Southampton, SO17 1BJ, UK; Ocean and Earth Science, National Oceanography Centre, SO17 1BJ, UK; Department of Biology and Geology, Babes-Bolyai University, Romania.
| | - John M Dyke
- School of Chemistry, University of Southampton, SO17 1BJ, UK.
| | - Richard B Cook
- nCATS National Centre for Advanced Tribology Southampton, University of Southampton, SO17 1BJ, UK
| | - Gareth Dyke
- Department of Biology and Geology, Babes-Bolyai University, Romania
| | - Roeland de Kat
- Aerodynamics and Flight Mechanics, University of Southampton, SO17 1BJ, UK; Faculty of Military Sciences, Netherlands Defence Academy, The Netherlands
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10
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Dyke JM, Emsley JW, Greenacre VK, Levason W, Monzittu FM, Reid G, De Luca G. Tertiary Phosphine and Arsine Complexes of Phosphorus Pentafluoride: Synthesis, Properties, and Electronic Structures. Inorg Chem 2020; 59:4517-4526. [PMID: 32186860 DOI: 10.1021/acs.inorgchem.9b03630] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of PMe3 or PPh3 with PF5 in anhydrous CH2Cl2 or hexane forms the white, moisture-sensitive complexes [PF5(PR3)] (R = Me, Ph). Similar reactions involving the diphosphines o-C6H4(PR2)2 afford the complexes [PF4{o-C6H4(PR2)2}][PF6]. The X-ray structures of [PF5(PR3)] and [PF4{o-C6H4(PMe2)2}][PF6] show pseudo-octahedral fluorophosphorus centers. Multinuclear NMR spectra (1H, 19F{1H}, 31P{1H}) show that in solution in CH2Cl2/CD2Cl2 the structures determined crystallographically are the only species present for [PF5(PMe3)] and [PF4{o-C6H4(PMe2)2}][PF6] but that [PF5(PPh3)] and [PF4{o-C6H4(PPh2)2}][PF6] exhibit reversible dissociation of the phosphine at ambient temperatures, although exchange slows at low temperatures. The complex 19F{1H} and 31P{1H} NMR spectra have been analyzed, including those of the cation [PF4{o-C6H4(PMe2)2}]+, which is a second-order AA'XX'B2M spin system. The unstable [PF5(AsMe3)], which decomposes in a few hours at ambient temperatures, has also been isolated and spectroscopically characterized; neither AsPh3 nor SbEt3 forms similar complexes. The electronic structures of the PF5 complexes have been explored by DFT calculations. The DFT optimized geometries for [PF5(PMe3)], [PF5(PPh3)], and [PF4{o-C6H4(PMe2)2}]+ are in good agreement with their respective crystal structure geometries. DFT calculations on the PF5-L complexes reveal the P-L bond strength falls with L in the order PMe3 > PPh3 > AsMe3, consistent with the experimentally observed stabilities, and in the PF5-L complexes, electron transfer from L to PF5 on forming these complexes also follows the order PMe3 > PPh3 ≈ AsMe3.
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Affiliation(s)
- John M Dyke
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | - James W Emsley
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | | | - William Levason
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | | | - Gillian Reid
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | - Giuseppina De Luca
- Department of Chemistry and Chemical Technologies, University of Calabria, Arcavacata di Rende 87036, Italy
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11
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Abstract
Photoionization with synchrotron radiation enables sensitive and selective monitoring of reactive intermediates in environments such as flames and plasmas.
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12
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Bhakhoa H, Rhyman L, Lee EP, Mok DKW, Ramasami P, Dyke JM. A study of the Group 1 metal tetra-aza macrocyclic complexes [M(Me 4cyclen)(L)] + using electronic structure calculations. Dalton Trans 2017; 46:15301-15310. [PMID: 29068443 DOI: 10.1039/c7dt03002a] [Citation(s) in RCA: 4] [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: 01/05/2023]
Abstract
Metal-cyclen complexes have a number of important applications. However, the coordination chemistry between metal ions and cyclen-based macrocycles is much less well studied compared to their metal ion-crown ether analogues. This work, which makes a contribution to address this imbalance by studying complex ions of the type [M(Me4cyclen)(L)]+, was initiated by results of an experimental study which prepared some Group 1 metal cyclen complexes, namely [Li(Me4cyclen)(H2O)][BArF] and [Na(Me4cyclen)(THF)][BArF] and obtained their X-ray crystal structures [J. M. Dyke, W. Levason, M. E. Light, D. Pugh, G. Reid, H. Bhakhoa, P. Ramasami, and L. Rhyman, Dalton Trans., 2015, 44, 13853]. The lowest [M(Me4cyclen)(L)]+ minimum energy structures (M = Li, Na, K, and L = H2O, THF, DEE, MeOH, DCM) are studied using density functional theory (DFT) calculations. The geometry of each [M(Me4cyclen)(L)]+ structure and, in particular, the conformation of L are found to be mainly governed by steric hindrance which decreases as the size of the ionic radius increases from Li+ → Na+ → K+. Good agreement of computed geometrical parameters of [Li(Me4cyclen)(H2O)]+ and [Na(Me4cyclen)(THF)]+ with the corresponding geometrical parameters derived from the crystal structures [Li(Me4cyclen)(H2O)]+[BArF]- and [Na(Me4cyclen)(THF)]+[BArF]- is obtained. Bonding analysis indicates that the stability of the [M(Me4cyclen)(L)]+ structures originates mainly from ionic interaction between the Me4cyclen/L ligands and the M+ centres. The experimental observation that [M(Me4cyclen)(L)]+[BArF]- complexes could be prepared in crystalline form for M+ = Li+ and Na+, but that experiments aimed at synthesising the corresponding K+, Rb+, and Cs+ complexes failed resulting in formation of [Me4cyclenH][BArF] is investigated using DFT and explicitly correlated calculations, and explained by considering production of [Me4cyclenH]+ by a hydrolysis reaction, involving traces of water, which competes with [M(Me4cyclen)(L)]+ formation. [Me4cyclenH]+ formation dominates for M+ = K+, Rb+, and Cs+ whereas formation of [M(Me4cyclen)(L)]+ is energetically favoured for M+ = Li+ and Na+. The results indicate that the number and type of ligands, play a key role in stabilising the [M(Me4cyclen)]+ complexes and it is hoped that this work will encourage experimentalists to prepare and characterise other [M(Me4cyclen)(L)]+ complexes.
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Affiliation(s)
- Hanusha Bhakhoa
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius.
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13
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Ng M, Mok DKW, Lee EPF, Dyke JM. The Atmospherically Important Reaction of Hydroxyl Radicals with Methyl Nitrate: A Theoretical Study Involving the Calculation of Reaction Mechanisms, Enthalpies, Activation Energies, and Rate Coefficients. J Phys Chem A 2017; 121:6554-6567. [DOI: 10.1021/acs.jpca.7b05035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Maggie Ng
- Department
of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Daniel K. W. Mok
- Department
of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Edmond P. F. Lee
- Department
of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | - John M. Dyke
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
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14
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Mok DKW, Dyke JM, Lee EPF. Simulation of the photodetachment spectrum of HHfO − using coupled-cluster calculations. J Chem Phys 2016; 145:244303. [DOI: 10.1063/1.4972816] [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: 11/14/2022] Open
Affiliation(s)
- Daniel K. W. Mok
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - John M. Dyke
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Edmond P. F. Lee
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
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15
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Chhantyal-Pun R, Welz O, Savee JD, Eskola AJ, Lee EPF, Blacker L, Hill HR, Ashcroft M, Khan MAH, Lloyd-Jones GC, Evans L, Rotavera B, Huang H, Osborn DL, Mok DKW, Dyke JM, Shallcross DE, Percival CJ, Orr-Ewing AJ, Taatjes CA. Direct Measurements of Unimolecular and Bimolecular Reaction Kinetics of the Criegee Intermediate (CH3)2COO. J Phys Chem A 2016; 121:4-15. [DOI: 10.1021/acs.jpca.6b07810] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rabi Chhantyal-Pun
- School of Chemistry, The University of Bristol, Cantock’s
Close BS8 1TS, U.K
| | - Oliver Welz
- Combustion Research Facility, Mail Stop
9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - John D. Savee
- Combustion Research Facility, Mail Stop
9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Arkke J. Eskola
- Combustion Research Facility, Mail Stop
9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Edmond P. F. Lee
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
- Department
of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Lucy Blacker
- School of Chemistry, The University of Bristol, Cantock’s
Close BS8 1TS, U.K
| | - Henry R. Hill
- School of Chemistry, The University of Bristol, Cantock’s
Close BS8 1TS, U.K
| | - Matilda Ashcroft
- School of Chemistry, The University of Bristol, Cantock’s
Close BS8 1TS, U.K
| | - M. Anwar H. Khan
- School of Chemistry, The University of Bristol, Cantock’s
Close BS8 1TS, U.K
| | - Guy C. Lloyd-Jones
- School of Chemistry, The University of Bristol, Cantock’s
Close BS8 1TS, U.K
| | - Louise Evans
- School of Chemistry, The University of Bristol, Cantock’s
Close BS8 1TS, U.K
| | - Brandon Rotavera
- Combustion Research Facility, Mail Stop
9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Haifeng Huang
- Combustion Research Facility, Mail Stop
9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - David L. Osborn
- Combustion Research Facility, Mail Stop
9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Daniel K. W. Mok
- The Centre
for Atmospheric Science, The School of Earth, Atmospheric and Environmental
Science, The University of Manchester, Simon Building, Brunswick Street, Manchester M13 9PL, U.K
| | - John M. Dyke
- Department
of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | | | - Carl J. Percival
- The Centre
for Atmospheric Science, The School of Earth, Atmospheric and Environmental
Science, The University of Manchester, Simon Building, Brunswick Street, Manchester M13 9PL, U.K
| | - Andrew J. Orr-Ewing
- School of Chemistry, The University of Bristol, Cantock’s
Close BS8 1TS, U.K
| | - Craig A. Taatjes
- Combustion Research Facility, Mail Stop
9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
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16
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Affiliation(s)
- Daniel K. W. Mok
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Edmond P. F. Lee
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - John M. Dyke
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
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17
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Schio L, Alagia M, Dias AA, Falcinelli S, Zhaunerchyk V, Lee EPF, Mok DKW, Dyke JM, Stranges S. A Study of H2O2 with Threshold Photoelectron Spectroscopy (TPES) and Electronic Structure Calculations: Redetermination of the First Adiabatic Ionization Energy (AIE). J Phys Chem A 2016; 120:5220-9. [DOI: 10.1021/acs.jpca.6b01039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Luca Schio
- IOM-CNR Tasc Laboratory, SS-14,
Km 163.5, Area Science Park, 34149 Basovizza, Trieste, Italy
| | - Michele Alagia
- IOM-CNR Tasc Laboratory, SS-14,
Km 163.5, Area Science Park, 34149 Basovizza, Trieste, Italy
| | - Antonio A. Dias
- LIBPhys-UNL,
Laboratory for Instrumentation, Biomedical Engineering and Radiation
Physics, Departamento de Física, Faculdade de Ciências
e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Stefano Falcinelli
- Dipartimento
di Ingegneria Civile ed Ambientale, Università di Perugia, 06125 Perugia, Italy
| | - Vitali Zhaunerchyk
- Department
of Physics, University of Gothenburg, 41296 Gothenburg, Sweden
| | - Edmond P. F. Lee
- School
of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
- Department
of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Daniel K. W. Mok
- Department
of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - John M. Dyke
- School
of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Stefano Stranges
- IOM-CNR Tasc Laboratory, SS-14,
Km 163.5, Area Science Park, 34149 Basovizza, Trieste, Italy
- Department
of Chemistry and Drug Technologies, Sapienza University, P.le A. Moro
5, 00185 Rome, Italy
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18
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Bhakhoa H, Rhyman L, Lee EPF, Ramasami P, Dyke JM. Can Cyclen Bind Alkali Metal Azides? A DFT Study as a Precursor to Synthesis. Chemistry 2016; 22:4469-82. [PMID: 26880648 DOI: 10.1002/chem.201504607] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Indexed: 11/10/2022]
Abstract
Can cyclen (1,4,7,10-tetraazacyclododecane) bind alkali metal azides? This question is addressed by studying the geometric and electronic structures of the alkali metal azide-cyclen [M(cyclen)N3] complexes using density functional theory (DFT). The effects of adding a second cyclen ring to form the sandwich alkali metal azide-cyclen [M(cyclen)2N3] complexes are also investigated. N3(-) is found to bind to a M(+) (cyclen) template to give both end-on and side-on structures. In the end-on structures, the terminal nitrogen atom of the azide group (N1) bonds to the metal as well as to a hydrogen atom of the cyclen ring through a hydrogen bond in an end-on configuration to the cyclen ring. In the side-on structures, the N3 unit is bonded (in a side-on configuration to the cyclen ring) to the metal through the terminal nitrogen atom of the azide group (N1), and through the other terminal nitrogen atom (N3) of the azide group by a hydrogen bond to a hydrogen atom of the cyclen ring. For all the alkali metals, the N3-side-on structure is lowest in energy. Addition of a second cyclen unit to [M(cyclen)N3] to form the sandwich compounds [M(cyclen)2N3] causes the bond strength between the metal and the N3 unit to decrease. It is hoped that this computational study will be a precursor to the synthesis and experimental study of these new macrocyclic compounds; structural parameters and infrared spectra were computed, which will assist future experimental work.
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Affiliation(s)
- Hanusha Bhakhoa
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, 80837, Mauritius
| | - Lydia Rhyman
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, 80837, Mauritius
| | - Edmond P F Lee
- School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.,Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Ponnadurai Ramasami
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, 80837, Mauritius. .,Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh, 11451, Saudi Arabia.
| | - John M Dyke
- School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
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19
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Chow R, Mok DKW, Lee EPF, Dyke JM. A theoretical study of the atmospherically important radical–radical reaction BrO + HO2; the product channel O2(a1Δg) + HOBr is formed with the highest rate. Phys Chem Chem Phys 2016; 18:30554-30569. [DOI: 10.1039/c6cp05877a] [Citation(s) in RCA: 8] [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: 11/21/2022]
Abstract
A theoretical study has been made of the BrO + HO2 reaction, a radical–radical reaction which contributes to ozone depletion in the atmosphere via production of HOBr.
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Affiliation(s)
- Ronald Chow
- Department of Applied Biology and Chemical Technology
- Hong Kong Polytechnic University
- Hung Hom
- China
| | - Daniel K. W. Mok
- Department of Applied Biology and Chemical Technology
- Hong Kong Polytechnic University
- Hung Hom
- China
| | - Edmond P. F. Lee
- Department of Applied Biology and Chemical Technology
- Hong Kong Polytechnic University
- Hung Hom
- China
- School of Chemistry
| | - John M. Dyke
- School of Chemistry
- University of Southampton
- Southampton SO17 1BJ
- UK
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20
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Ng M, Mok DK, Lee EP, Dyke JM. A theoretical investigation of the atmospherically important reaction between chlorine atoms and formic acid: determination of the reaction mechanism and calculation of the rate coefficient at different temperatures. Mol Phys 2015. [DOI: 10.1080/00268976.2014.980448] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Maggie Ng
- Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Daniel K.W. Mok
- Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Edmond P.F. Lee
- Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong
- School of Chemistry, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, UK
| | - John M. Dyke
- School of Chemistry, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, UK
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21
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Shallcross DE, Leather KE, Bacak A, Xiao P, Lee EPF, Ng M, Mok DKW, Dyke JM, Hossaini R, Chipperfield MP, Khan MAH, Percival CJ. Reaction between CH3O2 and BrO Radicals: A New Source of Upper Troposphere Lower Stratosphere Hydroxyl Radicals. J Phys Chem A 2015; 119:4618-32. [DOI: 10.1021/jp5108203] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Kimberley E. Leather
- School
of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Williamson Building, Oxford Road, Manchester M13 9PL, U.K
| | - Asan Bacak
- School
of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Williamson Building, Oxford Road, Manchester M13 9PL, U.K
| | - Ping Xiao
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Edmond P. F. Lee
- School
of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
- Department
of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Maggie Ng
- Department
of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Daniel K. W. Mok
- Department
of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - John M. Dyke
- School
of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Ryan Hossaini
- School
of Earth and Environment, University of Leeds, Leeds LS2 9JT, U.K
| | | | - M. Anwar H. Khan
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Carl J. Percival
- School
of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Williamson Building, Oxford Road, Manchester M13 9PL, U.K
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22
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Champion MJD, Dyke JM, Levason W, Light ME, Pugh D, Bhakhoa H, Rhyman L, Ramasami P, Reid G. Sodium Thioether Macrocyclic Chemistry: Remarkable Homoleptic Octathia Coordination to Na+. Inorg Chem 2015; 54:2497-9. [DOI: 10.1021/acs.inorgchem.5b00156] [Citation(s) in RCA: 9] [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: 01/06/2023]
Affiliation(s)
| | - John M. Dyke
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | - William Levason
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | - Mark E. Light
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | - David Pugh
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | - Hanusha Bhakhoa
- Computational
Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius
| | - Lydia Rhyman
- Computational
Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius
| | - Ponnadurai Ramasami
- Computational
Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius
| | - Gillian Reid
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
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23
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Ng M, Mok DKW, Lee EPF, Dyke JM. A theoretical study of the mechanism of the atmospherically relevant reaction of chlorine atoms with methyl nitrate, and calculation of the reaction rate coefficients at temperatures relevant to the troposphere. Phys Chem Chem Phys 2015; 17:7463-76. [DOI: 10.1039/c4cp06007e] [Citation(s) in RCA: 3] [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: 11/21/2022]
Abstract
Computed rate coefficients of the atmospherically important Cl + CH3ONO2 → HCl + CH2ONO2 reaction reported for the first time.
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Affiliation(s)
- Maggie Ng
- Department of Applied Biology and Chemical Technology
- Hong Kong Polytechnic University
- Hung Hom
- Hong Kong
| | - Daniel K. W. Mok
- Department of Applied Biology and Chemical Technology
- Hong Kong Polytechnic University
- Hung Hom
- Hong Kong
| | - Edmond P. F. Lee
- Department of Applied Biology and Chemical Technology
- Hong Kong Polytechnic University
- Hung Hom
- Hong Kong
- School of Chemistry
| | - John M. Dyke
- School of Chemistry
- University of Southampton
- Southampton SO17 1BJ
- UK
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24
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25
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Chow R, Ng M, Mok DKW, Lee EPF, Dyke JM. Rate Coefficients of the Cl + CH3C(O)OCH3 → HCl + CH3C(O)OCH2 Reaction at Different Temperatures Calculated by Transition-State Theory with ab Initio and Density Functional Theory Reaction Paths. J Phys Chem A 2014; 118:2040-55. [PMID: 24533502 DOI: 10.1021/jp5000864] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ronald Chow
- Department
of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Maggie Ng
- Department
of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Daniel K. W. Mok
- Department
of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Edmond P. F. Lee
- Department
of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong
- School
of Chemistry, Faculty of Natural and Environmental Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - John M. Dyke
- School
of Chemistry, Faculty of Natural and Environmental Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
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Ng M, Mok DK, Dyke JM, Lee EP. Decomposition reactions of hexafluoropropylene oxide (HFPO): Rate coefficients calculated at different temperatures using ab initio and DFT reaction paths. J Fluor Chem 2014. [DOI: 10.1016/j.jfluchem.2013.11.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
We have carried out high-level ab initio calculations on AlH2 and its anion, as well as Franck-Condon factor calculations, which include anharmonicity and Duschinsky rotation, to simulate the photodetachment spectrum of AlH2(-), with the aim of assigning the very recently reported photodetachment spectrum of AlH2(-) [X. Zhang, H. Wang, E. Collins, A. Lim, G. Ganteför, B. Kiran, H. Schnöckel, B. Eichhorn, and K. Bowen, J. Chem. Phys. 138, 124303 (2013)]. However, our simulated spectra do not support the assignment of the reported experimental spectrum to AlH2(-).
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Affiliation(s)
- Daniel K W Mok
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
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Copeland G, Lee EPF, Williams RG, Archibald AT, Shallcross DE, Dyke JM. Determination of the photolysis rate coefficient of monochlorodimethyl sulfide (MClDMS) in the atmosphere and its implications for the enhancement of SO2 production from the DMS + Cl2 reaction. Environ Sci Technol 2014; 48:1557-1565. [PMID: 24280000 DOI: 10.1021/es402956r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this work, the photolysis rate coefficient of CH3SCH2Cl (MClDMS) in the lower atmosphere has been determined and has been used in a marine boundary layer (MBL) box model to determine the enhancement of SO2 production arising from the reaction DMS + Cl2. Absorption cross sections measured in the 28000-34000 cm(-1) region have been used to determine photolysis rate coefficients of MClDMS in the troposphere at 10 solar zenith angles (SZAs). These have been used to determine the lifetimes of MClDMS in the troposphere. At 0° SZA, a photolysis lifetime of 3-4 h has been obtained. The results show that the photolysis lifetime of MClDMS is significantly smaller than the lifetimes with respect to reaction with OH (≈ 4.6 days) and with Cl atoms (≈ 1.2 days). It has also been shown, using experimentally derived dissociation energies with supporting quantum-chemical calculations, that the dominant photodissocation route of MClDMS is dissociation of the C-S bond to give CH3S and CH2Cl. MBL box modeling calculations show that buildup of MClDMS at night from the Cl2 + DMS reaction leads to enhanced SO2 production during the day. The extra SO2 arises from photolysis of MClDMS to give CH3S and CH2Cl, followed by subsequent oxidation of CH3S.
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Affiliation(s)
- G Copeland
- School of Chemistry, University of Southampton , Highfield, Southampton SO17 1BJ, U.K
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Percival CJ, Welz O, Eskola AJ, Savee JD, Osborn DL, Topping DO, Lowe D, Utembe SR, Bacak A, McFiggans G, Cooke MC, Xiao P, Archibald† AT, Jenkin ME, Derwent RG, Riipinen I, Mok DWK, Lee EPF, Dyke JM, Taatjes CA, Shallcross DE. Regional and global impacts of Criegee intermediates on atmospheric sulphuric acid concentrations and first steps of aerosol formation. Faraday Discuss 2013; 165:45-73. [DOI: 10.1039/c3fd00048f] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ng M, Mok DKW, Lee EPF, Dyke JM. Rate coefficients of the CF3CHFCF3+ H → CF3CFCF3+ H2reaction at different temperatures calculated by transition state theory withab initioand DFT reaction paths. J Comput Chem 2012; 34:545-57. [DOI: 10.1002/jcc.23163] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/28/2012] [Accepted: 08/31/2012] [Indexed: 11/07/2022]
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Lee EPF, Mok DKW, Shallcross DE, Percival CJ, Osborn DL, Taatjes CA, Dyke JM. Spectroscopy of the Simplest Criegee Intermediate CH2OO: Simulation of the First Bands in Its Electronic and Photoelectron Spectra. Chemistry 2012; 18:12411-23. [DOI: 10.1002/chem.201200848] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Indexed: 11/11/2022]
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Roscioni OM, Lee EPF, Dyke JM. Development and testing of a compact basis set for use in effective core potential calculations on rhodium complexes. J Comput Chem 2012; 33:2049-57. [DOI: 10.1002/jcc.23034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 05/11/2012] [Accepted: 05/14/2012] [Indexed: 11/10/2022]
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33
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Rhyman L, Armata N, Ramasami P, Dyke JM. A Study of the Atmospherically Important Reactions between Dimethyl Selenide (DMSe) and Molecular Halogens (X2 = Cl2, Br2, and I2) with ab initio Calculations. J Phys Chem A 2012; 116:5595-603. [DOI: 10.1021/jp302750a] [Citation(s) in RCA: 3] [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: 11/28/2022]
Affiliation(s)
- Lydia Rhyman
- Computational Chemistry Group,
Department of Chemistry, University of Mauritius, Réduit, Mauritius
| | - Nerina Armata
- School of Chemistry, University of Southampton, Southampton, UK SO17 1BJ
| | - Ponnadurai Ramasami
- Computational Chemistry Group,
Department of Chemistry, University of Mauritius, Réduit, Mauritius
| | - John M. Dyke
- School of Chemistry, University of Southampton, Southampton, UK SO17 1BJ
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Beccaceci S, Armata N, Ogden JS, Dyke JM, Rhyman L, Ramasami P. A study of the atmospherically important reactions of dimethylsulfide (DMS) with I2 and ICl using infrared matrix isolation spectroscopy and electronic structure calculations. Phys Chem Chem Phys 2012; 14:2399-407. [DOI: 10.1039/c2cp23392d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Taatjes CA, Welz O, Eskola AJ, Savee JD, Osborn DL, Lee EPF, Dyke JM, Mok DWK, Shallcross DE, Percival CJ. Direct measurement of Criegee intermediate (CH2OO) reactions with acetone, acetaldehyde, and hexafluoroacetone. Phys Chem Chem Phys 2012; 14:10391-400. [DOI: 10.1039/c2cp40294g] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Mok DKW, Lee EPF, Chau FT, Dyke JM. Franck-Condon simulation, including anharmonicity, of the photodetachment spectrum of P2H(-): restricted-spin coupled-cluster single-double plus perturbative triple and unrestricted-spin coupled-cluster single-double plus perturbative triple -F12x potential energy functions of P2H and P2H(-). J Chem Phys 2011; 135:124312. [PMID: 21974527 DOI: 10.1063/1.3640037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Geometry optimization and harmonic vibrational frequency calculations have been carried out on the X̃(2)A(') state of P(2)H and the X̃(1)A(') state of P(2)H(-) using the restricted-spin coupled-cluster single-double plus perturbative triple excitation [RCCSD(T)] and explicitly correlated unrestricted-spin coupled-cluster single-double plus perturbative triple excitation [UCCSD(T)-F12x] methods. For RCCSD(T) calculations, basis sets of up to the augmented correlation-consistent polarized valence quintuple-zeta (aug-cc-pV5Z) quality were employed, and contributions from extrapolation to the complete basis set limit and from core correlation of the P 2s(2)2p(6) electrons were also included. For UCCSD(T)-F12x calculations, different atomic orbital basis sets of triple-zeta quality with different associated complementary auxiliary basis sets and different geminal Slater exponents were used. When the P 2s(2)2p(6) core electrons were correlated in these F12x calculations, appropriate core-valence basis sets were employed. In addition, potential energy functions (PEFs) of the X̃(2)A(') state of P(2)H and the X̃(1)A(') state of P(2)H(-) were computed at different RCCSD(T) and UCCSD(T)-F12x levels, and were used in variational calculations of anharmonic vibrational wavefunctions, which were then utilized to calculate Franck-Condon factors (FCFs) between these two states, employing a method which includes allowance for anharmonicity and Duschinsky rotation. The photodetachment spectrum of P(2)H(-) was then simulated using the computed FCFs. Simulated spectra obtained using the RCCSD(T)/aug-cc-pV5Z and UCCSD(T)-F12x(x = a or b)/aug-cc-pCVTZ PEFs are compared and found to be essentially identical. Based on the computed FCFs, a more detailed assignment of the observed vibrational structure than previously reported, which includes "hot bands," has been proposed. Comparison between simulated and available experimental spectra has been made, and the currently most reliable sets of equilibrium geometrical parameters for P(2)H and its anion have been derived. The photodetachment spectrum of P(2)D, yet to be recorded, has also been simulated.
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Affiliation(s)
- Daniel K W Mok
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
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Mok DKW, Lee EPF, Chau FT, Dyke JM. The enthalpies of formation of AsX(n) molecules, where X=H, F or Cl, and n=1, 2 or 3, by RCCSD(T) and UCCSD(T)-F12x calculations. Phys Chem Chem Phys 2011; 13:9540-53. [PMID: 21487636 DOI: 10.1039/c1cp20490d] [Citation(s) in RCA: 15] [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: 11/21/2022]
Abstract
RCCSD(T) and UCCSD(T)-F12x calculations were performed on AsX(n) molecules, where X = H, F or Cl, and n = 1, 2 or 3, and related species, in order to evaluate their enthalpies of formation (ΔH(f)(Ø)). The recommended ΔH(f)(Ø) values obtained from the present investigation are AsH, 57.7(2); AsF, -7.9(3); AsCl, 27.2(4); AsH(2), 39.8(4); AsF(2), -96.6(9); AsCl(2), -17.8(10); AsH(3), 17.1(4); AsF(3)-196.0(5) and AsCl(3), -59.1(27) kcal mole(-1). These values are anchored only on one thermodynamic quantity, namely, ΔH(f)(Ø)(As) (= 70.3 kcal mole(-1)). In the calculations, the fully-relativistic small-core effective core potential (ECP10MDF) was used for As. Contributions from outer core correlation of As 3d(10) electrons were computed explicitly in both RCCSD(T) and UCCSD(T)-F12 calculations with additional tight basis functions designed for As 3d(10) electrons. Basis sets of up to augmented correlation-consistent polarized valence quintuple-zeta (aug-cc-pV5Z) quality were used in RCCSD(T) calculations and computed relative electronic energies were extrapolated to the complete basis set (CBS) limit. For the simplified, explicitly correlated UCCSD(T)-F12x calculations, basis sets of up to quadruple-zeta (QZ) quality were employed. Based on the RCCSD(T)/CBS benchmark values, the reliability of available theoretical and experimental values have been assessed.
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Affiliation(s)
- Daniel K W Mok
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
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Mok DKW, Lee EPF, Chau FT, Dyke JM. Franck-Condon simulation of the photoelectron spectrum of AsCl₂ and the photodetachment spectrum of AsCl ₂⁻ employing UCCSD(T)-F12a potential energy functions: IE and EA of AsCl₂. J Comput Chem 2011; 32:1648-60. [PMID: 21328405 DOI: 10.1002/jcc.21743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 12/08/2010] [Accepted: 12/08/2010] [Indexed: 12/22/2022]
Abstract
The currently most reliable theoretical estimates of the adiabatic ionization energies (AIE(0)) from the X̃(2)B(1) state of AsCl(2) to the X̃(1)A(1) and ã(3)B(1) states of AsCl 2+, and the electron affinity (EA(0)) of AsCl(2) , including ΔZPE corrections, are calculated as 8.687(11), 11.320(23), and 1.845(12) eV, respectively (estimated uncertainties based on basis-set effects at the RCCSD(T) level). State-of-the-art ab initio calculations, which include RCCSD(T), CASSCF/MRCI, and explicitly correlated RHF/UCCSD(T)-F12x (x = a or b) calculations with basis sets of up to quintuple-zeta quality, have been carried out on the X̃(2)B(1) state of AsCl(2) , the X̃(1)A(1) , ã(3)B(1) , and Ã(1)B(1) states of AsCl 2+, and the X̃(1)A(1) state of AsCl 2-. Relativistic, core correlation and complete basis-set (CBS) effects have been considered. In addition, computed UCCSD(T)-F12a potential energy functions of relevant electronic states of AsCl(2) , AsCl (2)(+), and AsCl( 2)(-) were used to calculate Franck-Condon factors, which were then used to simulate the valence photoelectron spectrum of AsCl(2) and the photodetachment spectrum of AsCl (2)(-), both yet to be recorded. Lastly, we have also computed the AIE and EA values for NCl(2) , PCl(2) , and AsCl(2) at the G4 level and for SbCl(2) at the RCCSD(T)/CBS level. The trends in the AIE and EA values of the group V pnictogen dichlorides, PnCl(2) , where Pn = N, P, As, and Sb, were examined. The AIE and EA of PCl(2) were found to be smaller than those of AsCl(2) , contrary to the order expected from the IE values of P and As.
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Affiliation(s)
- Daniel K W Mok
- Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong.
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Copeland G, Ghosh MV, Shallcross DE, Percival CJ, Dyke JM. A study of the alkene–ozone reactions, 2,3-dimethyl 2-butene + O3 and 2-methyl propene + O3, with photoelectron spectroscopy: measurement of product branching ratios and atmospheric implications. Phys Chem Chem Phys 2011; 13:17461-73. [DOI: 10.1039/c1cp21922g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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40
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Copeland G, Ghosh MV, Shallcross DE, Percival CJ, Dyke JM. A study of the ethene-ozone reaction with photoelectron spectroscopy: measurement of product branching ratios and atmospheric implications. Phys Chem Chem Phys 2011; 13:14839-47. [DOI: 10.1039/c0cp03004j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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41
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Eypper M, Innocenti F, Morris A, Dyke JM, Stranges S, West JB, King GC. Photoionization of iodine atoms: angular distributions and relative partial photoionization cross-sections in the energy region 11.0-23.0 eV. J Chem Phys 2010; 133:084302. [PMID: 20815564 DOI: 10.1063/1.3469798] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Relative partial photoionization cross-sections and angular distribution parameters, beta, have been measured for the first, I(+)((3)P(2))<--I((2)P(3/2)), and fourth, I(+)((1)D(2))<--I((2)P(3/2)), (5p)(-1) photoelectron (PE) bands of atomic iodine, by performing angle-resolved constant-ionic-state (CIS) measurements on these PE bands in the photon energy range 11.0-23.0 eV. Three Rydberg series, two ns and one nd series, which converge to the I(+) (3)P(1) limit at 11.33 eV and four Rydberg series, two ns and two nd series, which converge to the I(+) (1)D(2) limit at 12.15 eV were observed in the first PE band CIS spectra. The fourth band CIS spectrum showed structure in the 12.9-14.1 eV photon energy range, which is also seen in the first band CIS spectra. This structure arises from excitation to ns and nd Rydberg states that are parts of series converging to the I(+) (1)S(0) limit we reported on earlier, as well as 5s-->5p excitations in the photon energy range 17.5-22.5 eV. These atomic iodine CIS spectra show reasonably good agreement with the equivalent spectra obtained for atomic bromine. The beta-plots for the first PE band recorded up to the I(+) (3)P(1) and I(+) (1)D(2) limits only show resonances corresponding to some of the 5p-->nd excitations observed in the first band CIS spectra scanned to the I(+) (1)D(2) limit (12.15 eV). These plots are interpreted in terms of an angular momentum transfer model with the positive values of beta obtained on resonances corresponding to parity allowed j(t)=1 and 3 channels and the off-resonance negative beta values corresponding to parity unfavored channels, where j(t) is the quantum number for angular momentum transfer between the molecule, and the ion and photoelectron. The beta-plots recorded for iodine are significantly different from those obtained for atomic bromine. Comparison of the experimental CIS spectra and beta-plots with available theoretical results highlights the need for higher level calculations which include factors such as configuration interaction in the initial and final states, relativistic effects including spin-orbit interaction, and autoionization via resonant Rydberg states.
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Affiliation(s)
- Marie Eypper
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
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Eypper M, Innocenti F, Morris A, Stranges S, West JB, King GC, Dyke JM. Photoionization of iodine atoms: Rydberg series which converge to the I+(S10)←I(P23/2) threshold. J Chem Phys 2010; 132:244304. [DOI: 10.1063/1.3447382] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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Lee EPF, Mok DKW, Chau FT, Dyke JM. Ab initio calculations on the X̃ B21 and à A21 states of AsH2, and Franck–Condon simulation, including anharmonicity, of the Ã(0,0,0)-X̃ single vibronic level emission spectrum of AsH2. J Chem Phys 2010; 132:234309. [DOI: 10.1063/1.3442748] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Beccaceci S, Ogden JS, Dyke JM. Spectroscopic study of the reaction between Br2 and dimethyl sulfide (DMS), and comparison with a parallel study made on Cl2 + DMS: possible atmospheric implications. Phys Chem Chem Phys 2010; 12:2075-82. [DOI: 10.1039/b917173h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Mok DKW, Lee EPF, Chau FT, Dyke JM. Franck–Condon simulation of the photoelectron spectrum of AsF2 and the photodetachment spectrum of AsF2− using ab initio calculations: Ionization energy and electron affinity of AsF2. Phys Chem Chem Phys 2010; 12:9075-87. [DOI: 10.1039/c003688a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Cheng F, Dyke JM, Ferrante F, Hector AL, Levason W, Reid G, Webster M, Zhang W. Synthesis and structural characterisation of germanium(ii) halide complexes with neutral N-donor ligands. Dalton Trans 2010; 39:847-56. [DOI: 10.1039/b911016j] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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47
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Mok DKW, Chau FT, Lee EPF, Dyke JM. High-level ab initio calculations on HGeCl and the equilibrium geometry of the A1A'' state derived from Franck-Condon analysis of the single-vibronic-level emission spectra of HGeCl and DGeCl. J Comput Chem 2009; 31:476-91. [PMID: 19499544 DOI: 10.1002/jcc.21331] [Citation(s) in RCA: 5] [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: 11/11/2022]
Abstract
CCSD(T) and/or CASSCF/MRCI calculations have been carried out on the X(1)A' and A(1)A'' states of HGeCl. The fully relativistic effective core potential, ECP10MDF, and associated standard valence basis sets of up to the aug-cc-pV5Z quality were employed for Ge. Contributions from core correlation and extrapolation to the complete basis set limit were included in determining the computed equilibrium geometrical parameters and relative electronic energy of these two states of HGeCl. Based on the currently, most systematic CCSD(T) calculations performed in this study, the best theoretical geometrical parameters of the X(1)A' state are r(e)(HGe) = 1.580 +/- 0.001 A, theta(e) = 93.88 +/- 0.01 degrees and r(e)(GeCl) = 2.170 +/- 0.001 A. In addition, Franck-Condon factors including allowance for anharmonicity and Duschinsky rotation between these two states of HGeCl and DGeCl were calculated employing CCSD(T) and CASSCF/MRCI potential energy functions, and were used to simulate A(1)A'' --> X(1)A' SVL emission spectra of HGeCl and DGeCl. The iterative Franck-Condon analysis (IFCA) procedure was carried out to determine the equilibrium geometrical parameters of the A(1)A'' state of HGeCl by matching the simulated, and available experimental SVL emission spectra of HGeCl and DGeCl of Tackett et al., J Chem Phys 2006, 124, 124320, using the available, estimated experimental equilibrium (r(e)(z)) structure for the X(1)A' state, while varying the equilibrium geometrical parameters of the A(1)A'' state systematically. Employing the derived IFCA geometry of r(e)(HGe) = 1.590 A, r(e)(GeCl) = 2.155 A and theta(e)(HGeCl) = 112.7 degrees for the A(1)A'' state of HGeCl in the spectral simulation, the simulated absorption and SVL emission spectra of HGeCl and DGeCl agree very well with the available experimental LIF and SVL emission spectra, respectively.
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Affiliation(s)
- Daniel K W Mok
- Department of Applied Biology and Chemical Technology, the Hong Kong Polytechnic University, Hung Hom, Hong Kong.
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Mok DWK, Lee EPF, Chau FT, Dyke JM. Franck−Condon Simulations including Anharmonicity of the Ã1A′′−X̃1A′ Absorption and Single Vibronic Level Emission Spectra of HSiCl and DSiCl. J Chem Theory Comput 2009; 5:565-79. [DOI: 10.1021/ct800513v] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel W. K. Mok
- Department of Applied Biology and Chemical Technology, the Hong Kong Polytechnic University, Hung Hom, Hong Kong, and School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Edmond P. F. Lee
- Department of Applied Biology and Chemical Technology, the Hong Kong Polytechnic University, Hung Hom, Hong Kong, and School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Foo-tim Chau
- Department of Applied Biology and Chemical Technology, the Hong Kong Polytechnic University, Hung Hom, Hong Kong, and School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - John M. Dyke
- Department of Applied Biology and Chemical Technology, the Hong Kong Polytechnic University, Hung Hom, Hong Kong, and School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
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Lee EPF, Mok DKW, Chau FT, Dyke JM. A combinedab initioand Franck-Condon factor simulation study on the photodetachment spectrum of ScO2−. J Comput Chem 2009; 30:337-45. [DOI: 10.1002/jcc.21059] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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50
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Todorova TK, Infante I, Gagliardi L, Dyke JM. Theoretical Study of the Gas-Phase Chemiionization Reactions La + O and La + O2. J Phys Chem A 2008; 112:7825-30. [DOI: 10.1021/jp804578d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tanya K. Todorova
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - Ivan Infante
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - Laura Gagliardi
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - John M. Dyke
- Department of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
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