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Milton JR, Jankiewicz BJ, Max JP, Vinueza NR, Kirkpatrick LM, Campbell K, Gallardo VA, Reece JN, Kenttämaa HI. Study on the Gas-Phase Reactivity of Charged Pyridynes. J Org Chem 2021; 86:9979-9993. [PMID: 34242505 DOI: 10.1021/acs.joc.1c00618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reactivities of three isomeric, charged ortho-pyridynes, the 1,2-, 2,3-, and 3,4-didehydropyridinium cations, were examined in the gas phase using Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry. The structures of selected product ions were probed using collision-activated dissociation (CAD) experiments in a linear quadrupole ion trap (LQIT) mass spectrometer. Mechanisms based on quantum chemical calculations are proposed for the formation of all major products. The products of the reactions of the charged ortho-pyridynes in the gas phase were found to closely resemble those formed upon reactions of neutral ortho-arynes in solution, but the mechanisms of these reactions exhibit striking differences. Additionally, no radical reactions were observed for any of the charged ortho-pyridynes examined, in contrast to previous proposals that ortho-benzyne can occasionally react via radical mechanisms. Finally, the relative reactivities of those charged gaseous ortho-pyridynes that yielded similar product distributions were found to be affected mainly by the (calculated) vertical electron affinities of the dehydrocarbon sites, which suggests that the reactivity of these species is controlled by polar effects.
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Affiliation(s)
- Jacob R Milton
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - Bartłomiej J Jankiewicz
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States.,Institute of Optoelectronics, Military University of Technology, gen. S. Kaliskiego 2, 00-908 Warsaw, Poland
| | - Joann P Max
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - Nelson R Vinueza
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - Lindsey M Kirkpatrick
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States.,Ryan White Center for Pediatric Infectious Disease, Indiana University School of Medicine, 705 Riley Hospital Drive, Room 3032, Indianapolis, Indiana 46202, United States
| | - Karinna Campbell
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - Vanessa A Gallardo
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - Jennifer N Reece
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - Hilkka I Kenttämaa
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
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2
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Ding D, Jiang H, Ma X, Nash JJ, Kenttämaa HI. Effects of the Distance between Radical Sites on the Reactivities of Aromatic Biradicals. J Org Chem 2020; 85:8415-8428. [PMID: 32482062 DOI: 10.1021/acs.joc.0c00658] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Coupling of the radical sites in isomeric benzynes is known to hinder their radical reactivity. In order to determine how far apart the radical sites must be for them not to interact, the gas-phase reactivity of several isomeric protonated (iso)quinoline- and acridine-based biradicals was examined. All the (iso)quinolinium-based biradicals were found to react slower than the related monoradicals with similar vertical electron affinities (i.e., similar polar effects). In sharp contrast, the acridinium-based biradicals, most with the radical sites farther apart than in the (iso)quinolinium-based systems, showed greater reactivities than the relevant monoradicals with similar vertical electron affinities. The greater distances between the two radical sites in these biradicals lead to very little or no spin-spin coupling, and no suppression of radical reactivity was observed. Therefore, the radical sites can still interact if they are located on adjacent benzene rings and only after being separated further than that does no coupling occur. The most reactive radical site of each biradical was experimentally determined to be the one predicted to be more reactive based on the monoradical reactivity data. Therefore, the calculated vertical electron affinities of relevant monoradicals can be used to predict which radical site is most reactive in the biradicals.
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Affiliation(s)
- Duanchen Ding
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Hanning Jiang
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Xin Ma
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - John J Nash
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Hilkka I Kenttämaa
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
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3
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Yue L, Li J, Xie X, Guo C, Yin X, Yin Q, Chen Y, Pan Y, Ding C. Ortho-hydroxyl effect and proton transfer via ion-neutral complex: the fragmentation study of protonated imine resveratrol analogues in mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2016; 51:518-523. [PMID: 27434810 DOI: 10.1002/jms.3778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 03/30/2016] [Accepted: 04/20/2016] [Indexed: 06/06/2023]
Abstract
The fragmentation pathways of protonated imine resveratrol analogues in the gas-phase were investigated by electrospray ionization-tandem mass spectrometry. Benzyl cations were formed in the imine resveratrol analogues that had an ortho-hydroxyl group on the benzene ring A. The specific elimination of the quinomethane neutral, CH2 = C6 H4 = O, from the two isomeric ions [M1 + H](+) and [M3 + H](+) via the corresponding ion-neutral complexes was observed. The fragmentation pathway for the related meta-isomer, ion [M2 + H](+) and the other congeners was not observed. Accurate mass measurements and additional experiments carried out with a chlorinated analogue and the trideuterated isotopolog of M1 supported the overall interpretation of the fragmentation phenomena observed. It is very helpful for understanding the intriguing roles of ortho-hydroxyl effect and ion-neutral complexes in fragmentation reactions and enriching the knowledge of the gas-phase chemistry of the benzyl cation. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Lei Yue
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - Jing Li
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
- Institute of Biological Engineering, Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
| | - Xiaodong Xie
- Department of Chemistry, Fudan University, 220 Handan Road, Shanghai, 200433, China
| | - Cheng Guo
- Cancer Institute, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310009, China
| | - Xinchi Yin
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - Qi Yin
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - Yinjuan Chen
- Department of Chemistry, Fudan University, 220 Handan Road, Shanghai, 200433, China
| | - Yuanjiang Pan
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - Chuanfan Ding
- Department of Chemistry, Fudan University, 220 Handan Road, Shanghai, 200433, China
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4
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Goetz AE, Shah TK, Garg NK. Pyridynes and indolynes as building blocks for functionalized heterocycles and natural products. Chem Commun (Camb) 2015; 51:34-45. [DOI: 10.1039/c4cc06445c] [Citation(s) in RCA: 202] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This feature article showcases the use of pyridynes and indolynes to construct functionalized heterocycles and complex natural products.
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Affiliation(s)
- Adam E. Goetz
- Department of Chemistry and Biochemistry
- University of California
- Los Angeles
- USA
| | - Tejas K. Shah
- Department of Chemistry and Biochemistry
- University of California
- Los Angeles
- USA
| | - Neil K. Garg
- Department of Chemistry and Biochemistry
- University of California
- Los Angeles
- USA
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5
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Hansen CS, Kirk BB, Blanksby SJ, Trevitt AJ. Ultraviolet Photodissociation of the N-Methylpyridinium Ion: Action Spectroscopy and Product Characterization. J Phys Chem A 2013; 117:10839-46. [DOI: 10.1021/jp4075515] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christopher S. Hansen
- ARC Centre of Excellence
for Free Radical Chemistry and Biotechnology and School of Chemistry, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Benjamin B. Kirk
- ARC Centre of Excellence
for Free Radical Chemistry and Biotechnology and School of Chemistry, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Stephen J. Blanksby
- ARC Centre of Excellence
for Free Radical Chemistry and Biotechnology and School of Chemistry, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Adam J. Trevitt
- ARC Centre of Excellence
for Free Radical Chemistry and Biotechnology and School of Chemistry, University of Wollongong, Wollongong, New South Wales 2522, Australia
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6
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Williams PE, Jankiewicz BJ, Yang L, Kenttämaa HI. Properties and reactivity of gaseous distonic radical ions with aryl radical sites. Chem Rev 2013; 113:6949-85. [PMID: 23987564 PMCID: PMC3889672 DOI: 10.1021/cr400121w] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Peggy E. Williams
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47906
| | | | - Linan Yang
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47906
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7
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Rau NJ, Wenthold PG. Experimental investigation of the absolute enthalpies of formation of 2,3-, 2,4-, and 3,4-pyridynes. J Phys Chem A 2011; 115:10353-62. [PMID: 21812461 DOI: 10.1021/jp2051068] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The absolute enthalpies of formation of 3,4-, 2,3-, and/or 2,4-didehydropyridines (3,4-, 2,3- and 2,4-pyridynes) have been determined by using energy-resolved collision-induced dissociation of deprotonated 2- and 3-chloropyridines. Bracketing experiments find the gas-phase acidities of 2- and 3-chloropyridines to be 383 ± 2 and 378 ± 2 kcal/mol, respectively. Whereas deprotonation of 3-chloropyridine leads to formation of a single ion isomer, deprotonation of the 2-chloro isomer results in a nearly 60:40 mixture of regioisomers. The enthalpy of formation of 3,4-pyridyne is measured to be 121 ± 3 kcal/mol by using the chloride dissociation energy for deprotonated 3-chloropyridine. The structure of the product formed upon dissociation of the ion from 2-chloropyridine cannot be unequivocally assigned because of the isomeric mixture of reactant ions and the fact that the potential neutral products (2,3-pyridyne and 2,4-pyridyne) are predicted by high level spin-flip coupled-cluster calculations to be nearly the same in energy. Consequently, the enthalpies of formation for both neutral products are assigned to be 130 ± 3 kcal/mol. Comparison of the enthalpies of dehydrogenation of benzene and pyridine indicates that the nitrogen in the pyridine ring does not have any effect on the stability of the aryne triple bond in 3,4-pyridyne, destabilizes the aryne triple bond in 2,3-pyridyne, and stabilizes the 1,3-interaction in 2,4-pyridyne compared to that in m-benzyne. Natural bond order calculations show that the effects on the 2,3- and 2,4-pyridynes result from polarization of the electrons caused by interaction with the lone pair. The polarization in 2,4-pyridyne is stabilizing because it creates a 1,2-interaction between the nitrogen and dehydrocarbons that is stronger than the 1,3-interaction between the dehydrocarbons.
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Affiliation(s)
- Nathan J Rau
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA
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8
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Benassi M, Eberlin MN. Absolute assignment of constitutional isomers via structurally diagnostic fragment ions: the challenging case of α- and β-acyl naphthalenes. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2010; 21:2041-2050. [PMID: 20947371 DOI: 10.1016/j.jasms.2010.08.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 08/24/2010] [Accepted: 08/24/2010] [Indexed: 05/30/2023]
Abstract
A general mass spectrometric method is described for the absolute assignment of α- or β-acyl naphthalenes, via which the gaseous α- and β-naphthoyl cations of m/z 155 are used as structurally diagnostic fragment ions (SDFI). These stable acylium ions are common and normally abundant fragment ions of acylnaphthalenes in general. Using a pentaquadrupole mass spectrometer, CID experiments with argon and ion/molecule reactions with 2-methyl-1,3-dioxolane, isoprene, acetonitrile and propionitrile were performed but failed to distinguish the two SDFI. Reactions with ethyl vinyl ether and several homologues as well as ethyl vinyl thioether were, however, successful. In reactions with ethyl vinyl ether, the α-SDFI form a pair of diagnostic product ions of m/z 165 and m/z 181, which are absent in the corresponding spectrum of the β-SDFI. Methyl 4-(1-naphthyl)-2,4-dioxobutanoate was used as a test molecule for this class of constitutional isomers and absolute structural assignment as an α-acyl naphthalene was correctly performed via the characterization of its α-SDFI.
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Affiliation(s)
- Mario Benassi
- Thomson Mass Spectrometry Laboratory, Chemistry Institute, University of Campinas, Campinas, Brazil
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9
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Corilo YE, Eberlin MN. Recognizing alpha-, beta- or gamma-substitution in pyridines by mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2008; 43:1636-1640. [PMID: 18563867 DOI: 10.1002/jms.1442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A general mass spectrometric method able to recognize the site of substitution of monosubstituted pyridines is described. The method requires that the molecule under investigation forms, upon ionization and dissociation, the respective alpha-, beta- or gamma- pyridinium ion of m/z 78. Pyridinium ions are stable and common fragments of ionized and protonated pyridines and are found to function as appropriate structurally diagnostic fragment ions. They can be identified by their characteristic and nearly identical collision-induced dissociation behavior and distinguished by the combined use of two structurally diagnostic ion/molecule reactions with acetonitrile and 2-methyl-1,3-dioxolane. alpha-, beta- or gamma-substitution in pyridines can, therefore, be securely recognized via an MS-only method based on structurally diagnostic ions and by the inspection of a single molecule (no need for intracomparisons within the whole set of isomers).
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Affiliation(s)
- Yuri E Corilo
- ThoMSon Mass Spectrometry Laboratory, Institute of Chemistry, State University of Campinas, 13083-970 Campinas SP, Brazil
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10
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Synthesis and Binding Properties of 1,3,5-Tris(2-arylthiomethyl)mesitylene: A Selective Ag (I) Ionophore. B KOREAN CHEM SOC 2008. [DOI: 10.5012/bkcs.2008.29.2.417] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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11
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An unprecedented ortho effect in mass spectrometric fragmentation of even-electron negative ions from hydroxyphenyl carbaldehydes and ketones. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.04.147] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Cooks RG, Chen H, Eberlin MN, Zheng X, Tao WA. Polar Acetalization and Transacetalization in the Gas Phase: The Eberlin Reaction. Chem Rev 2006; 106:188-211. [PMID: 16402776 DOI: 10.1021/cr0400921] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R G Cooks
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA.
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13
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Maurin P, Ibrahim-Ouali M, Parrain JL, Santelli M. Structure of substituted o-benzynes and their cycloaddition to ketene dialkyl acetals. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0166-1280(03)00412-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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14
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Liu HC, Yang S, Zhang XH, Wu YD. Unusual Chemistry of the Complex Mg•+(2-Fluoropyridine) Activated by the Photoexcitation of Mg•+. J Am Chem Soc 2003; 125:12351-7. [PMID: 14519021 DOI: 10.1021/ja036476a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The photochemistry of a gas-phase complex, Mg*(+)(2-fluoropyridine), has been studied in the spectral range of approximately 230-440 nm with a molecular beam coupled with a time-of-flight mass spectrometer. Surprisingly rich chemistry has been observed. Aside from the evaporative photofragment, Mg*(+), an abundant photoproduct, C(4)H(4)*(+), is observed after the electronic excitation of Mg(+). The formation of this photoproduct is associated with the loss of a stable species, CN[bond]Mg[bond]F. Also identified in this work are reactive pathways that occur with the elimination of HCN, HF, or MgF from the complex. The observed photoreactions have been examined in detail using quantum mechanics methods. A distinct structural feature of the complex is the direct attachment of Mg*(+) to the N atom of fluoropyridine due to the strong electrostatic interaction. The key to the rich photochemistry is the formation of the FMg(+)(C(5)H(4)N) intermediate, through facile fluorine migration. Plausible photoreaction mechanisms have been proposed. These mechanisms account for the evolution of the energized complex with the pre-defined structure en route to the target photoproducts that we have detected.
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Affiliation(s)
- Hai-Chuan Liu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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16
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Abstract
In the past 25 years, a tremendous amount of work has been published on the ion/molecule reactions of organic species. This review provides an overview of the areas where gas phase ion chemistry has made a contribution to our understanding of fundamental organic reaction processes. It is clear that the gas phase work can provide insights into subtle features of reaction mechanisms that could not be addressed by conventional condensed phase methods. The study of ion/molecule reactions has already had a major impact on the way that organic chemists think about reaction mechanisms and interpret substituent effects. Moreover, it has heightened our awareness of the importance of solvation effects and how they can alter not only absolute rates but also relative rates, leading in some cases to complete reversals in reactivity patterns. A large body of work could not be included in this review due to space limitations. For example, the study of thermochemistry in the gas phase (i.e., acidities, basicities, bond strengths, binding energies, etc.) has provided a wealth of data that has been exceptionally useful in interpreting organic reaction mechanisms. This has spilled over into the study of organometallic systems, and several groups are making major headway in using mass spectrometry to probe the stability and reactivity of transition metal species. Finally, work involving chemical ionization has provided abundant information on gas phase reaction mechanisms. The future appears to be very promising for the study of gas phase organic reaction mechanisms. In particular, the emergence of new ionization techniques and more powerful mass analyzers will allow chemists to explore a wider range of species. Although still at an early stage, the gas phase study of biochemical transformations offers great promise and has been facilitated by electrospray and matrix assisted laser desorption ionization methods. In addition, these techniques provide a means for introducing important, metal-centered catalytic species into the gas phase and exploring the details of their reactivity. Finally, mass spectrometry continues to play a major role in the study of atmospheric ion chemistry and is providing important kinetic as well as mechanistic data.
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Affiliation(s)
- S Gronert
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California 94132, USA
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Le HT, Gerbaux P, Flammang R, Nguyen MT. Collisional activation of protonated halogeno-pyridines: different behaviour of target gases. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)00491-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Holmes RJ, O'Hair RA, McFadyen WD. Electrospray ionization tandem mass spectrometric studies of competitive pyridine loss from platinum(II) ethylenediamine complexes by the kinetic method. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2000; 14:2385-2392. [PMID: 11114055 DOI: 10.1002/1097-0231(20001230)14:24<2385::aid-rcm172>3.0.co;2-m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The competition between pyridine ligand loss in square planar Pt(II) complexes has been examined using the doubly and singly charged ions of complexes consisting of platinum(ethylenediamine) coordinated to two different substituted pyridines. Collision induced dissociation (CID) of [Pt(en)Py(1)Py(2)](2+) (where Py(1) = one of ten different substituted pyridines and Py(2) = pyridine) results in loss of the protonated pyridines to yield the singly charged platinum ions [Pt(en)Py(1)-H](+) and [Pt(en)Py(2)-H](+). In contrast, fragmentation of [Pt(en)Py(1)Py(2)-H](+) results in neutral pyridine loss to yield the ions [Pt(en)Py(1)-H](+) and [Pt(en)Py(2)-H](+). In the latter case, the correlation between relative losses of each pyridine compared to their gas-phase proton affinities is poor. A novel chloride ion abstraction reaction occurs for the fragmentation of [Pt(en)Py(1)Py(2)](2+) when Py(1) = o-C(5)H(4)CIN and Py(2) = C(5)H(5)N, to yield the [Pt(en)(Cl)Py(2)](+) and [o-C(5)H(4)N](+) pair of ions. In order to model this process the competition between nitrogen and chlorine binding in [Pt(NH(3))(3)(o-NC(5)H(4)Cl)](2+) has been examined using density functional theory (DFT) calculations at the B3LYP/LANL2DZ level of theory. Both adducts are minima with the N adduct being more stable than the Cl adduct by 22.7 kcal mol(-1). Furthermore, the Cl adduct exhibits a significant stretching of the C-Cl bond (to 1.935 A), consistent with the observed chloride ion abstraction reaction, which is endothermic by 9.0 kcal mol(-1) (relative to the N adduct).
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Affiliation(s)
- R J Holmes
- School of Chemistry, University of Melbourne, Victoria 3010, Australia
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