1
|
Damont A, Olivier MF, Warnet A, Lyan B, Pujos-Guillot E, Jamin EL, Debrauwer L, Bernillon S, Junot C, Tabet JC, Fenaille F. Proposal for a chemically consistent way to annotate ions arising from the analysis of reference compounds under ESI conditions: A prerequisite to proper mass spectral database constitution in metabolomics. JOURNAL OF MASS SPECTROMETRY : JMS 2019; 54:567-582. [PMID: 31083780 DOI: 10.1002/jms.4372] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 04/25/2019] [Accepted: 04/30/2019] [Indexed: 06/09/2023]
Abstract
Nowadays, high-resolution mass spectrometry is widely used for metabolomic studies. Thanks to its high sensitivity, it enables the detection of a large range of metabolites. In metabolomics, the continuous quest for a metabolite identification as complete and accurate as possible has led during the last decade to an ever increasing development of public MS databases (including LC-MS data) concomitantly with bioinformatic tool expansion. To facilitate the annotation process of MS profiles obtained from biological samples, but also to ease data sharing, exchange, and exploitation, the standardization and harmonization of the way to describe and annotate mass spectra seemed crucial to us. Indeed, under electrospray (ESI) conditions, a single metabolite does not produce a unique ion corresponding to its protonated or deprotonated form but could lead to a complex mixture of signals. These MS signals result from the existence of different natural isotopologues of the same compound and also to the potential formation of adduct ions, homomultimeric and heteromultimeric ions, fragment ions resulting from "prompt" in-source dissociations. As a joint reflection process within the French Infrastructure for Metabolomics and Fluxomics (MetaboHUB) and with the purpose of developing a robust and exchangeable annotated MS database made from pure reference compounds (chemical standards) analysis, it appeared to us that giving the metabolomics community some clues to standardize and unambiguously annotate each MS feature was a prerequisite to data entry and further efficient querying of the mass spectral database. The use of a harmonized notation is also mandatory for interlaboratory MS data exchange. Additionally, thorough description of the variety of MS signals arising from the analysis of a unique metabolite might provide greater confidence on its annotation.
Collapse
Affiliation(s)
- Annelaure Damont
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
| | - Marie-Françoise Olivier
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
| | - Anna Warnet
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
| | - Bernard Lyan
- Plateforme d'Exploration du Métabolisme, MetaboHUB Clermont, Université Clermont Auvergne, INRA, UNH, F-63000, Clermont-Ferrand, France
| | - Estelle Pujos-Guillot
- Plateforme d'Exploration du Métabolisme, MetaboHUB Clermont, Université Clermont Auvergne, INRA, UNH, F-63000, Clermont-Ferrand, France
| | - Emilien L Jamin
- Toxalim (Research Centre in Food Toxicology), Metatoul-AXIOM platform, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, F-31027, Toulouse, France
| | - Laurent Debrauwer
- Toxalim (Research Centre in Food Toxicology), Metatoul-AXIOM platform, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, F-31027, Toulouse, France
| | - Stéphane Bernillon
- UMR1332 Biologie du Fruit et Pathologie, INRA, Univ. Bordeaux, Plateforme Métabolome du Centre de Génomique Fonctionnelle Bordeaux-MetaboHUB, IBVM, Centre INRA de Nouvelle Aquitaine-Bordeaux, 71 av Edouard Bourlaux, 33140, Villenave d'Ornon, France
| | - Christophe Junot
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
| | - Jean-Claude Tabet
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
- CNRS, Institut Parisien de Chimie Moléculaire, IPCM, Sorbonne Université, 75005, Paris, France
| | - François Fenaille
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
| |
Collapse
|
2
|
Xie X, Wang Z, Li Y, Zhan L, Nie Z. Investigation and Applications of In-Source Oxidation in Liquid Sampling-Atmospheric Pressure Afterglow Microplasma Ionization (LS-APAG) Source. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:1036-1047. [PMID: 27995501 DOI: 10.1007/s13361-016-1550-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/28/2016] [Accepted: 10/29/2016] [Indexed: 06/06/2023]
Abstract
A liquid sampling-atmospheric pressure afterglow microplasma ionization (LS-APAG) source is presented for the first time, which is embedded with both electrospray ionization (ESI) and atmospheric pressure afterglow microplasma ionization (APAG) techniques. This ion source is capable of analyzing compounds with diverse molecule weights and polarities. An unseparated mixture sample was detected as a proof-of-concept, giving complementary information (both polarities and non-polarities) with the two ionization modes. It should also be noted that molecular mass can be quickly identified by ESI with clean and simple spectra, while the structure can be directly studied using APAG with in-source oxidation. The ionization/oxidation mechanism and applications of the LS-APAG source have been further explored in the analysis of nonpolar alkanes and unsaturated fatty acids/esters. A unique [M + O - 3H]+ was observed in the case of individual alkanes (C5-C19) and complex hydrocarbons mixture under optimized conditions. Moreover, branched alkanes generated significant in-source fragments, which could be further applied to the discrimination of isomeric alkanes. The technique also facilitates facile determination of double bond positions in unsaturated fatty acids/esters due to diagnostic fragments (the acid/ester-containing aldehyde and acid oxidation products) generated by on-line ozonolysis in APAG mode. Finally, some examples of in situ APAG analysis by gas sampling and surface sampling were given as well. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Xiaobo Xie
- Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhenpeng Wang
- National Center for Mass Spectrometry in Beijing, Beijing, 100190, China
| | - Yafeng Li
- Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Lingpeng Zhan
- Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zongxiu Nie
- Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- National Center for Mass Spectrometry in Beijing, Beijing, 100190, China.
| |
Collapse
|
3
|
Wang HY, Zhang JT, Sun SH, Zhang SS, Zhang F, Zhu H, Guo YL. Study on the accelerated Gutknecht self-cyclocondensation of amino-sugars under atmospheric pressure chemical ionization conditions. RSC Adv 2015. [DOI: 10.1039/c5ra22331h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
An unexpected catalyst-free gas phase Gutknecht self-cyclocondensation of d-glucosamine hydrochloride to 2,5-deoxyfructosazine under APCI conditions.
Collapse
Affiliation(s)
- Hao-Yang Wang
- State Key Laboratory of Organmetallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai
- Shanghai Institute of Organic Chemistry
- Chinese Academy of Sciences
- Shanghai
- China
| | - Jun-Ting Zhang
- State Key Laboratory of Organmetallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai
- Shanghai Institute of Organic Chemistry
- Chinese Academy of Sciences
- Shanghai
- China
| | - Shi-Hao Sun
- Zhengzhou Tobacco Research Institute
- China National Tobacco Corporation
- Zhengzhou 450001
- China
| | - Shu-Sheng Zhang
- State Key Laboratory of Organmetallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai
- Shanghai Institute of Organic Chemistry
- Chinese Academy of Sciences
- Shanghai
- China
| | - Fang Zhang
- State Key Laboratory of Organmetallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai
- Shanghai Institute of Organic Chemistry
- Chinese Academy of Sciences
- Shanghai
- China
| | - Hui Zhu
- State Key Laboratory of Organmetallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai
- Shanghai Institute of Organic Chemistry
- Chinese Academy of Sciences
- Shanghai
- China
| | - Yin-Long Guo
- State Key Laboratory of Organmetallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai
- Shanghai Institute of Organic Chemistry
- Chinese Academy of Sciences
- Shanghai
- China
| |
Collapse
|
4
|
Benassi M, Garcia-Reyes JF, Spengler B. Ambient ion/molecule reactions in low-temperature plasmas (LTP): reactive LTP mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:795-804. [PMID: 23495026 DOI: 10.1002/rcm.6500] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 12/24/2012] [Accepted: 12/29/2012] [Indexed: 06/01/2023]
Abstract
RATIONALE Ion/molecule reactions are commonly used to characterize structures due to their high specificity. Herein, we present ambient ion/molecule reactions performed in the course of low-temperature plasma (LTP) ionization of condensed-phase analytes in order to increase the specificity of LTP-based ambient analysis. METHODS The ion population of the cold plasma is modified by addition of a reagent to the plasma before it is directed at a surface bearing the analyte. Desorbed ions were analyzed using linear ion trap-Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). RESULTS Acylium ions generated from tetramethylurea react with 1,3-dioxane analyte to afford distinctive Eberlin product ions. Reactions of alkylamines, such as n-hexylamine and n-octylamine, with benzaldehyde produce the corresponding imines. Reaction of ruthenocene with trifluoroacetic anhydride forms the unusual trifluoroacetate ruthenocene. CONCLUSIONS A LTP source can be used to generate reagent ions that can undergo ion/molecule reactions in the ambient environment with an analyte at condensed phase on a surface. The experiment is a 'reactive' version of the standard low-temperature plasma (LTP) ambient ionization experiment. This approach provides additional information by combining ion/molecule chemistry with conventional MS and MS/MS data to characterize particular analytes.
Collapse
Affiliation(s)
- Mario Benassi
- Institute of Inorganic and Analytical Chemistry, Justus Liebig University, 35392, Giessen, Germany
| | | | | |
Collapse
|
5
|
Lu M, Campbell JL, Chauhan R, Grapperhaus CA, Chen H. Probing the reactivity and radical nature of oxidized transition metal-thiolate complexes by mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:502-512. [PMID: 23315345 DOI: 10.1007/s13361-012-0537-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Revised: 10/11/2012] [Accepted: 10/15/2012] [Indexed: 06/01/2023]
Abstract
Transition metal thiolate complexes such as [PPN](+)[RuL3](-) (PPN = bis(triphenylphosphoranylidene) ammonium and L = diphenylphosphinobenzenethiolate) are known to undergo addition reactions with unsaturated hydrocarbons via the formation of new C-S bonds in solution upon oxidation. The reaction mechanism is proposed to involve metal-stabilized thiyl radical intermediates, a new type of distonic ions such as [RuL3](+) ion in the case of [PPN](+)[RuL3](-). This study presents the reactivity and structure investigation of [RuL3](+) by mass spectrometry (MS) in conjunction with ion/molecule reactions. The addition reactions of [RuL3](+) with alkenes or methyl ketones in the gas phase are indeed observed, in agreement with the proposed mechanism. Such reactivity is also maintained by several fragment ions of [RuL3](+), indicating the preserved thiyl diradical core structure is responsible for the addition reaction. The thiyl radical nature of [RuL3](+) was further verified by the ion/molecule reaction of [RuL3](+) with dimethyl disulfide, in which the characteristic CH3S• transfer occurs, both at atmospheric pressure and also at low pressure (~mTorr). These results provide, for the first time, clear mass spectrometric evidence of the radical nature of [RuL3](+) (i.e., the distonic ion structure of [RuL3](+)), arising from the oxidation of non-innocent thiolate ligands of the complex [PPN](+)[RuL3](-). Similar thiolate complexes, including ReL3 and NiL2, were also examined. Although reactions of oxidized ReL3 or NiL2 with CH3SSCH3 take place at atmospheric pressure, the corresponding reaction did not occur in vacuum. Consistent with these data, the addition of ethylene was not observed either, indicating lower reactivities of [ReL3](+) and [NiL2](+) in comparison to [RuL3](+).
Collapse
Affiliation(s)
- Mei Lu
- Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA
| | | | | | | | | |
Collapse
|
6
|
Pichette S, Aubert-Nicol S, Lessard J, Spino C. Regioselective Photochemical Rearrangement of N-Mesyloxylactams. European J Org Chem 2012. [DOI: 10.1002/ejoc.201101222] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
7
|
Dalla-Vechia L, Santos VG, Godoi MN, Cantillo D, Kappe CO, Eberlin MN, de Souza ROMA, Miranda LSM. On the mechanism of the Dakin–West reaction. Org Biomol Chem 2012; 10:9013-20. [DOI: 10.1039/c2ob26560e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
8
|
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.
Collapse
Affiliation(s)
- Mario Benassi
- Thomson Mass Spectrometry Laboratory, Chemistry Institute, University of Campinas, Campinas, Brazil
| | | |
Collapse
|
9
|
Wu L, Eberlin MN, Corilo YE, Liu DQ, Yin H. Dimerization of ionized 4-(methyl mercapto)-phenol during ESI, APCI and APPI mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2009; 44:1389-1394. [PMID: 19697320 DOI: 10.1002/jms.1633] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A novel ion/molecule reaction was observed to occur under electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and atmospheric pressure photo ionization (APPI) conditions, leading to dimerization of ionized 4-(methyl mercapto)-phenol followed by fast H(*) loss. The reaction is particularly favored during ESI, which suggests that this ion/molecule reaction can occur both in the solution inside the ESI-charged droplets and in the gas-phase environment of most other atmospheric pressure ionization techniques. The dimerization reaction is inherent to the electrolytic process during ESI, whereas it is more by ion/molecule chemistry in nature during APCI and APPI. From the tandem mass spectrometry (MS/MS) data, accurate mass measurements, hydrogen/deuterium (H/D) exchange experiments and density functional theory (DFT) calculations, two methyl sulfonium ions appear to be the most likely products of this electrophilic aromatic substitution reaction. The possible occurrence of this unexpected reaction complicates mass spectral data interpretation and can be misleading in terms of structural assignment as reported herein for 4-(methyl mercapto)-phenol.
Collapse
Affiliation(s)
- Lianming Wu
- Analytical Sciences, Chemical Development, GlaxoSmithKline, 709 Swedeland Road, King of Prussia, PA 19406, USA.
| | | | | | | | | |
Collapse
|
10
|
Kamal A, Markandeya N, Shankaraiah N, Reddy C, Prabhakar S, Reddy C, Eberlin M, Silva Santos L. Chemoselective Aromatic Azido Reduction with Concomitant Aliphatic Azide Employing Al/Gd Triflates/NaI and ESI-MS Mechanistic Studies. Chemistry 2009; 15:7215-24. [DOI: 10.1002/chem.200900853] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
11
|
Benassi M, Moraes LAB, Cabrini LG, Dias LC, Aguilar AM, Romeiro GA, Eberlin LS, Eberlin MN. Recognition of Cyclic, Acyclic, Exocyclic, and Spiro Acetals via Structurally Diagnostic Ion/Molecule Reactions with the (CH3)2N-C+═O Acylium Ion. J Org Chem 2008; 73:5549-57. [DOI: 10.1021/jo8008269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Mario Benassi
- ThoMSon Mass Spectrometry Laboratory, State University of Campinas, Campinas-SP, Brazil 13083-970, University of São Paulo, Ribeirão Preto, SP, Brazil, Synthetic Organic Chemistry Laboratory, State University of Campinas, Campinas-SP, Brazil, Federal University of São Paulo, Diadema Campus, 09972-270, Diadema, SP, Brazil, and Institute of Chemistry, Fluminense Federal University, Rio de Janeiro, RJ, Brazil
| | - Luiz Alberto B. Moraes
- ThoMSon Mass Spectrometry Laboratory, State University of Campinas, Campinas-SP, Brazil 13083-970, University of São Paulo, Ribeirão Preto, SP, Brazil, Synthetic Organic Chemistry Laboratory, State University of Campinas, Campinas-SP, Brazil, Federal University of São Paulo, Diadema Campus, 09972-270, Diadema, SP, Brazil, and Institute of Chemistry, Fluminense Federal University, Rio de Janeiro, RJ, Brazil
| | - Liliane G. Cabrini
- ThoMSon Mass Spectrometry Laboratory, State University of Campinas, Campinas-SP, Brazil 13083-970, University of São Paulo, Ribeirão Preto, SP, Brazil, Synthetic Organic Chemistry Laboratory, State University of Campinas, Campinas-SP, Brazil, Federal University of São Paulo, Diadema Campus, 09972-270, Diadema, SP, Brazil, and Institute of Chemistry, Fluminense Federal University, Rio de Janeiro, RJ, Brazil
| | - Luiz Carlos Dias
- ThoMSon Mass Spectrometry Laboratory, State University of Campinas, Campinas-SP, Brazil 13083-970, University of São Paulo, Ribeirão Preto, SP, Brazil, Synthetic Organic Chemistry Laboratory, State University of Campinas, Campinas-SP, Brazil, Federal University of São Paulo, Diadema Campus, 09972-270, Diadema, SP, Brazil, and Institute of Chemistry, Fluminense Federal University, Rio de Janeiro, RJ, Brazil
| | - Andrea M. Aguilar
- ThoMSon Mass Spectrometry Laboratory, State University of Campinas, Campinas-SP, Brazil 13083-970, University of São Paulo, Ribeirão Preto, SP, Brazil, Synthetic Organic Chemistry Laboratory, State University of Campinas, Campinas-SP, Brazil, Federal University of São Paulo, Diadema Campus, 09972-270, Diadema, SP, Brazil, and Institute of Chemistry, Fluminense Federal University, Rio de Janeiro, RJ, Brazil
| | - Gilberto A. Romeiro
- ThoMSon Mass Spectrometry Laboratory, State University of Campinas, Campinas-SP, Brazil 13083-970, University of São Paulo, Ribeirão Preto, SP, Brazil, Synthetic Organic Chemistry Laboratory, State University of Campinas, Campinas-SP, Brazil, Federal University of São Paulo, Diadema Campus, 09972-270, Diadema, SP, Brazil, and Institute of Chemistry, Fluminense Federal University, Rio de Janeiro, RJ, Brazil
| | - Livia S. Eberlin
- ThoMSon Mass Spectrometry Laboratory, State University of Campinas, Campinas-SP, Brazil 13083-970, University of São Paulo, Ribeirão Preto, SP, Brazil, Synthetic Organic Chemistry Laboratory, State University of Campinas, Campinas-SP, Brazil, Federal University of São Paulo, Diadema Campus, 09972-270, Diadema, SP, Brazil, and Institute of Chemistry, Fluminense Federal University, Rio de Janeiro, RJ, Brazil
| | - Marcos N. Eberlin
- ThoMSon Mass Spectrometry Laboratory, State University of Campinas, Campinas-SP, Brazil 13083-970, University of São Paulo, Ribeirão Preto, SP, Brazil, Synthetic Organic Chemistry Laboratory, State University of Campinas, Campinas-SP, Brazil, Federal University of São Paulo, Diadema Campus, 09972-270, Diadema, SP, Brazil, and Institute of Chemistry, Fluminense Federal University, Rio de Janeiro, RJ, Brazil
| |
Collapse
|
12
|
Wang X, Liu R, Jin Y, Liang X. TEMPO/HCl/NaNO2 catalyst: a transition-metal-free approach to efficient aerobic oxidation of alcohols to aldehydes and ketones under mild conditions. Chemistry 2008; 14:2679-85. [PMID: 18293352 DOI: 10.1002/chem.200701818] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Hydrochloric acid, a very inexpensive and readily available inorganic acid, has been found to cooperate exquisitely with NaNO(2)/TEMPO in catalyzing the molecular-oxygen-driven oxidation of a broad range of alcohol substrates to the corresponding aldehydes and ketones. This transition-metal-free catalytic oxidative conversion is novel and represents an interesting alternative route to the corresponding carbonyl compounds to the metal-catalyzed aerobic oxidation of alcohols. The reaction is highly selective with respect to the desired product when carried out at room temperature in air at atmospheric pressure. Notably, the use of very inexpensive NaNO(2) and HCl in combination with TEMPO for this highly selective aerobic oxidation of alcohols in air at ambient temperature makes the reaction operationally and economically very attractive. The results of mechanistic studies, performed with the aid of electrospray ionization mass spectrometry (ESI-MS), are presented and discussed. TEMPO, TEMPOH, and TEMPO(+) were observed in the redox cycle by means of ESI-MS. On the basis of these observations, a mechanism is proposed that may provide an insight into the newly developed aerobic alcohol oxidation.
Collapse
Affiliation(s)
- Xinliang Wang
- Dalian Institute of Chemical Physics, Institution Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, PR China
| | | | | | | |
Collapse
|
13
|
Dalmázio I, de Urzedo APFM, Alves TMA, Catharino RR, Eberlin MN, Nascentes CC, Augusti R. Electrospray ionization mass spectrometry monitoring of indigo carmine degradation by advanced oxidative processes. JOURNAL OF MASS SPECTROMETRY : JMS 2007; 42:1273-8. [PMID: 17902099 DOI: 10.1002/jms.1159] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The degradation of the dye indigo carmine in aqueous solution induced by two oxidative processes (H(2)O(2)/iodide and O(3)) was investigated. The reactions were monitored by electrospray ionization mass spectrometry in the negative ion mode, ESI(-)-MS, and the intermediates and oxidation products characterized by ESI(-)-MS/MS. Both oxidative systems showed to be highly efficient in removing the color of the dye aqueous solutions. In the ESI(-)-MS of the indigo carmine solution treated with H(2)O(2) and H(2)O(2)/iodide, the presence of the ions of m/z 210 (indigo carmine in its anionic form, 1), 216, 226, 235, and 244 was noticeable. The anion of m/z 235 was proposed to be the unprecedented hydroperoxide intermediate 2 formed in solution via an electrophilic attack by hydroxyl and hydroperoxyl radicals of the exocyclic C=C bond of 1. This intermediate was suggested to be rapidly converted into the anionic forms of 2,3-dioxo-1H-indole-5-sulfonic acid (3, m/z 226), 2-amino-alpha-oxo-5-sulfo-benzeneacetic acid (4, m/z 244), and 2-amino-5-sulfo-benzoic acid (5, m/z 216). In the ESI(-)-MS of the indigo carmine solution treated with O(3), two main anions were detected: m/z 216 (5) and 244 (4). Both products were proposed to be produced via an unstable ozonide intermediate. Other anions in this ESI(-) mass spectrum were attributed to be [4 - H + Na](-) of m/z 266, [4 - H](2-) of m/z 121.5, and [5 - H](2-) of m/z 107.5. ESI-MS/MS data were consistent with the proposed structures for the anionic products 2-5.
Collapse
Affiliation(s)
- Ilza Dalmázio
- Department of Chemistry, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | | | | | | | | | | | | |
Collapse
|
14
|
Dalmázio I, Almeida MO, Augusti R, Alves TMA. Monitoring the degradation of tetracycline by ozone in aqueous medium via atmospheric pressure ionization mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2007; 18:679-87. [PMID: 17234428 DOI: 10.1016/j.jasms.2006.12.001] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Revised: 11/30/2006] [Accepted: 12/03/2006] [Indexed: 05/12/2023]
Abstract
The degradation of tetracycline (1) by ozone in aqueous solution was investigated. High performance liquid chromatography (HPLC), UV-visible spectroscopy (UV-Vis), and total organic carbon (TOC) analyses revealed that although tetracycline was quickly consumed under this oxidative condition, it did not mineralize at all. Continuous monitoring by electrospray ionization mass spectrometry in the positive ion mode, ESI(+)-MS, revealed that tetracycline (1), detected in its protonated form ([1 + H]+) of m/z 445, reacted to yield almost exclusively two unprecedented oxidation products (2 and 3) via a net insertion of one and two oxygen atoms, respectively. Compound 2, suggested to be formed via an initial 1,3-dipolar cycloaddition of ozone at the C11a-C12 double-bond of 1, and Compound 3, proposed to be produced via a subsequent ozone attack at the C2-C3 double-bond of 2, were detected in their protonated forms in the ESI(+)-MS, i.e., [2 + H]+ of m/z 461 and [3 + H]+ of m/z 477, and were further characterized by ESI(+)-MS(n). LC-APCI(+)-MS (liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry in the positive ion mode) experiments corroborated the results.
Collapse
Affiliation(s)
- Ilza Dalmázio
- Departamento de Química, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | | | | |
Collapse
|
15
|
Amarante GW, Benassi M, Sabino AA, Esteves PM, Coelho F, Eberlin MN. Formation of substituted N-oxide hydroxyquinolines from o-nitrophenyl Baylis–Hillman adduct: a new key intermediate intercepted by ESI-(+)-MS(/MS) monitoring. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.09.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
16
|
Sparrapan R, Eberlin LS, Haddad R, Cooks RG, Eberlin MN, Augusti R. Ambient Eberlin reactions via desorption electrospray ionization mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2006; 41:1242-6. [PMID: 16888754 DOI: 10.1002/jms.1088] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
|
17
|
Zhang X, Liao Y, Qian R, Wang H, Guo Y. Investigation of radical cation in electrophilic fluorination by ESI-MS. Org Lett 2006; 7:3877-80. [PMID: 16119921 DOI: 10.1021/ol051281o] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reaction solutions of selectfluor (1) with triphenylethylene (4a) and tetraphenylethylene (4b) were monitored by ESI-MS and ESI-MS/MS. Detection and characterization of the key radical cationic intermediates 5a.+ and 5b.+) fully supports the SET mechanism in electrophilic fluorination as depicted above. [reaction: see text]
Collapse
Affiliation(s)
- Xiang Zhang
- Shanghai Mass Spectrometry Center, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | | | | | | | | |
Collapse
|
18
|
Meurer EC, Eberlin MN. The atmospheric pressure Meerwein reaction. JOURNAL OF MASS SPECTROMETRY : JMS 2006; 41:470-6. [PMID: 16498596 DOI: 10.1002/jms.1005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We have already shown that the in-vacuum gas-phase Meerwein reaction of (thio)acylium ions is general in nature and useful for class-selective screening of cyclic (thio)epoxides. Herein we report that this gas-phase reaction can also be performed efficiently at atmospheric pressure under both electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) conditions. This alternative expands the range of molecules that can be reacted by gas-phase Meerwein reaction. Phenyl epoxide, thiirane, 3-methoxy-2,2-dimethyloxirane, propylene oxide, 2,2'-bioxirane, trans-1,3-diphenyl-2,3-epoxypropan-1-one, epichloridrine and propylene oxide are shown to react efficiently in both ESI and APCI conditions. Tetramethylurea (TMU) and (thio)TMU were both used as dopants, being co-injected with either toluene, acetonitrile or methanol solutions of the (thio)epoxides, with similar results. In both ESI and APCI, (thio)TMU is protonated preferentially, and these labile species dissociate promptly to yield (CH3)2N-C+=O and (CH3)2NCS+, which are the least acidic and most reactive (thio)acylium ions so far tested in the gas-phase Meerwein reaction. Under the low-energy ESI conditions set to favor both the formation of the (thio)acylium ion and ion/molecule reactions, (CH3)2NCO(S)+ react competitively with (thio)TMU to form acylated (thio)TMU and with the (thio)epoxide to form the characteristic Meerwein products. Enhanced selectivity in structural characterization or for the screening of (thio)epoxides is achieved by performing on-line collision-induced dissociation of Meerwein products, particularly for the more structurally complex (thio)epoxides.
Collapse
Affiliation(s)
- Eduardo C Meurer
- Institute of Chemistry, State University of Campinas, UNICAMP, 13083-970, Brazil
| | | |
Collapse
|
19
|
Eberlin MN. Structurally diagnostic ion/molecule reactions: class and functional-group identification by mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2006; 41:141-56. [PMID: 16447303 DOI: 10.1002/jms.998] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
This article discusses the application of gas-phase ion/molecule reactions for fine structural elucidation in mass spectrometry. This approach is illustrated via a representative collection of class- and functional group-selective reactions, a few of historical relevance as well as by more recent and instructive examples, and their applications. The focus is on reactions performed under well-controlled conditions of sequential mass spectrometry, discussing key mechanistic details and potential applications. Recent and innovative strategies that allow these reactions to be performed under ambient conditions, making this fast, selective and sensitive approach for structural investigation much more generally applicable, are also discussed.
Collapse
Affiliation(s)
- Marcos N Eberlin
- Institute of Chemistry, State University of Campinas, ThoMSon Laboratory for Mass Spectrometry, 13083-970 Campinas, SP, Brazil.
| |
Collapse
|
20
|
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.
| | | | | | | | | |
Collapse
|
21
|
Dalmázio I, Santos LS, Lopes RP, Eberlin MN, Augusti R. Advanced oxidation of caffeine in water: on-line and real-time monitoring by electrospray ionization mass spectrometry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2005; 39:5982-8. [PMID: 16173554 DOI: 10.1021/es047985v] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
High performance liquid chromatography (HPLC), ultraviolet spectroscopy (UV), and total organic carbon (TOC) analyses show that caffeine is quickly and completely degraded underthe oxidative conditions of the UV/H2O2,TiO2/ UV, and Fenton systems but that the organic carbon content of the solution decreases much more slowly. Continuous on-line and real-time monitoring by electrospray ionization mass (ESI-MS) and tandem mass spectrometric experiments (ESI-MS/MS) as well as high accuracy MS measurements and gas chromatography-mass spectrometry analysis show that caffeine is first oxidized to N-dimethylparabanic acid likely via initial OH insertion to the C4=C8 caffeine double bond. A second degradation intermediate, di(N-hidroxymethyl)parabanic acid, has been identified by ESI-MS and characterized by ESI-MS/MS and high accuracy mass measurements. This polar and likely relatively unstable compound, which is not detected by off-line GC-MS analysis, is likely formed via further oxidation of N-dimethylparabanic acid at both of its N-methyl groups and constitutes an unprecedented intermediate in the degradation of caffeine.
Collapse
Affiliation(s)
- Ilza Dalmázio
- Chemistry Department, Federal University of Minas Gerais-UFMG, Belo Horizonte, MG 31270-901, Brazil
| | | | | | | | | |
Collapse
|
22
|
Qian R, Guo H, Liao Y, Guo Y, Ma S. Probing the Mechanism of the Palladium-Catalyzed Addition of Organoboronic Acids to Allenes in the Presence of AcOH by ESI-FTMS. Angew Chem Int Ed Engl 2005; 44:4771-4. [PMID: 15988772 DOI: 10.1002/anie.200463101] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Rong Qian
- Shanghai Mass Spectrometry Center, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, P. R. China
| | | | | | | | | |
Collapse
|
23
|
Qian R, Guo H, Liao Y, Guo Y, Ma S. Probing the Mechanism of the Palladium-Catalyzed Addition of Organoboronic Acids to Allenes in the Presence of AcOH by ESI-FTMS. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200463101] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
24
|
Paim LA, Augusti DV, Dalmázio I, Alves TMDA, Augusti R, Siebald HG. Electrospray ionization and tandem mass spectrometry characterization of novel heterotrimetallic Ru(η5-C5H5)(dppf)SnX3 complexes and their heterobimetallic Ru(η5-C5H5)(dppf)X precursors. Polyhedron 2005. [DOI: 10.1016/j.poly.2005.03.053] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
25
|
Popov IA, Chen H, Kharybin ON, Nikolaev EN, Cooks RG. Detection of explosives on solid surfaces by thermal desorption and ambient ion/molecule reactions. Chem Commun (Camb) 2005:1953-5. [PMID: 15834469 DOI: 10.1039/b419291e] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple, fast and direct method is presented for detecting traces of solid explosives on cotton swabs or in particulate samples: ions are transferred into a mass spectrometer after thermal desorption and corona discharge chemical ionization in ambient air; specificity is enhanced using ambient ion/molecule reactions or by conventional tandem mass spectrometry.
Collapse
Affiliation(s)
- Igor A Popov
- Department of Chemistry, 560 Oval Drive, Purdue University, West Lafayette, IN 47907, USA
| | | | | | | | | |
Collapse
|
26
|
Gozzo FC, Santos LS, Augusti R, Consorti CS, Dupont J, Eberlin MN. Gaseous Supramolecules of Imidazolium Ionic Liquids: ?Magic? Numbers and Intrinsic Strengths of Hydrogen Bonds. Chemistry 2004; 10:6187-93. [PMID: 15515085 DOI: 10.1002/chem.200305742] [Citation(s) in RCA: 219] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Electrospray ionization mass spectrometry (ESI-MS) is found to gently and efficiently transfer small to large as well as singly to multiply charged [X+]n[A-]m supramolecules of imidazolium ion (X+) ionic liquids to the gas phase, and to reveal "magic numbers" for their most favored assemblies. Tandem mass spectrometric experiments (ESI-MS/MS) were then used to dissociate, via low-energy collision activation, mixed and loosely bonded [A- - - -X- - - -A']- and [X- - - -A- - - -X']+ gaseous supramolecules, as well as their higher homologues, and to estimate and order via Cooks' kinetic method (CKM) and B3LYP/6-311G(d,p) calculations the intrinsic solvent-free magnitude of hydrogen bonds. For the five anions studied, the relative order of intrinsic hydrogen-bond strengths to the 1-n-butyl-3-methylimidazolium ion [X1]+ is: CF3CO2- (zero) > BF4- (-3.1) > PF6- (-10.0) > InCl4- (-16.4) and BPh4- (-17.6 kcal mol(-1)). The relative hydrogen-bond strength for InCl4- was measured via CKM whereas those for the other anions were calculated and used as CKM references. A good correlation coefficient (R=0.998) between fragment ion ratios and calculated hydrogen-bond strengths and an effective temperature (Teff) of 430 K demonstrate the CKM reliability for measuring hydrogen-bond strengths in gaseous ionic liquid supramolecules. Using CKM and Teff of 430 K, the intrinsic hydrogen-bond strengths of BF4- for the three cations investigated is: 1-n-butyl-3-methyl-imidazolium ion (0) > 1,3-di-[(R)-3-methyl-2-butyl]-imidazolium ion (-2.4) > 1,3-di-[(R)-alpha-methylbenzyl]-imidazolium ion (-3.0 kcal mol(-1)). As evidenced by "magic" numbers, greater stabilities are found for the [(X1)2(BF4)3]- and [(X1)5A4]+ supramolecules (A not equal InCl4-).
Collapse
Affiliation(s)
- Fabio C Gozzo
- Thomson Mass Spectrometry Laboratory, Institute of Chemistry, State University of Campinas, UNICAMP, 13083-970 Campinas, SP, Brazil
| | | | | | | | | | | |
Collapse
|
27
|
Domingos JB, Longhinotti E, Brandão TAS, Santos LS, Eberlin MN, Bunton CA, Nome F. Reaction of Bis(2,4-dinitrophenyl) Phosphate with Hydrazine and Hydrogen Peroxide. Comparison of O- and N- Phosphorylation. J Org Chem 2004; 69:7898-905. [PMID: 15527267 DOI: 10.1021/jo048737k] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nonionic hydrazine reacts with anionic bis(2,4-dinitrophenyl) phosphate (BDNPP), giving 2,4-dinitrophenyl hydrazine and dianionic 2,4-dinitrophenyl phosphate by an S(N)2(Ar) reaction, and at the phosphoryl center, giving 2,4-dinitrophenoxide ion and a transient phosphorylated hydrazine that rearranges intramolecularly to N-(2,4-dinitrophenyl)-N-phosphonohydrazine. Approximately 58% of the reaction at pD = 10 occurs by N-phosphorylation, as shown by (31)P NMR spectroscopy. Reaction of HO(2)(-) is wholly at phosphorus, and the intermediate peroxophosphate reacts intramolecularly, displacing a second 2,4-dinitrophenoxide ion, or with H(2)O(2), giving 2,4-dinitrophenyl phosphate and O(2). Rate constants of O- and N-phosphorylation in reactions at phosphorus of NH(2)NH(2), HO(2)(-), and NH(2)OH and its methyl derivatives follow Bronsted relationships with similar slopes, but plots differ for oxygen and nitrogen nucleophiles. The reaction with NH(2)NH(2) has been probed by using both NMR spectroscopy and electrospray ionization mass and tandem mass spectrometry, with the novel interception of key reaction intermediates in the course of reaction.
Collapse
Affiliation(s)
- Josiel B Domingos
- Chemistry Department, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil
| | | | | | | | | | | | | |
Collapse
|
28
|
Domingos JB, Longhinotti E, Brandão TAS, Bunton CA, Santos LS, Eberlin MN, Nome F. Mechanisms of Nucleophilic Substitution Reactions of Methylated Hydroxylamines with Bis(2,4-dinitrophenyl)phosphate. Mass Spectrometric Identification of Key Intermediates. J Org Chem 2004; 69:6024-33. [PMID: 15373487 DOI: 10.1021/jo0494735] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mono- and dimethylation of hydroxylamine on nitrogen does not significantly affect rates of initial attack of NHMeOH and NMe(2)OH on bis(2,4-dinitrophenyl)phosphate (BDNPP), which is largely by oxygen phosphorylation. O-Methylation, however, blocks this reaction and NH(2)OMe then slowly reacts with BDNPP via N-attack at phosphorus and at the aryl group. With NHMeOH, the initial product of O-attack at phosphorus reacts further, either by reaction with a second NHMeOH or by a spontaneous shift of NHMe to the aryl group via a transient cyclic intermediate. There is a minor N-attack of NHMeOH on BDNPP in an S(N)2(Ar) reaction. Reactions occurring via N-attack are blocked by N-dimethylation, and reaction of NMe(2)OH with BDNPP occurs via O-attack, generating a long-lived product. Reaction mechanisms have been probed, and intermediates identified, by using both NMR and MS spectroscopy, with the novel interception of key reaction intermediates in the course of reaction by electrospray ionization mass and tandem mass spectrometry.
Collapse
Affiliation(s)
- Josiel B Domingos
- Chemistry Department, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil
| | | | | | | | | | | | | |
Collapse
|
29
|
Meurer EC, Chen H, Riter LS, Cooks RG, Eberlin MN. Meerwein reaction of phosphonium ions with epoxides and thioepoxides in the gas phase. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2004; 15:398-405. [PMID: 14998542 DOI: 10.1016/j.jasms.2003.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2003] [Revised: 11/06/2003] [Accepted: 11/06/2003] [Indexed: 05/24/2023]
Abstract
Phosphonium ions are shown to undergo a gas-phase Meerwein reaction in which epoxides (or thioepoxides) undergo three-to-five-membered ring expansion to yield dioxaphospholanium (or oxathiophospholanium) ion products. When the association reaction is followed by collision-induced dissociation (CID), the oxirane (or thiirane) is eliminated, making this ion molecule reaction/CID sequence a good method of net oxygen-by-sulfur replacement in the phosphonium ions. This replacement results in a characteristic mass shift of 16 units and provides evidence for the cyclic nature of the gas-phase Meerwein product ions, while improving selectivity for phosphonium ion detection. This reaction sequence also constitutes a gas-phase route to convert phosphonium ions into their sulfur analogs. Phosphonium and related ions are important targets since they are commonly and readily formed in mass spectrometric analysis upon dissociative electron ionization of organophosphorous esters. The Meerwein reaction should provide a new and very useful method of recognizing compounds that yield these ions, which includes a number of chemical warfare agents. The Meerwein reaction proceeds by phosphonium ion addition to the sulfur or oxygen center, followed by intramolecular nucleophilic attack with ring expansion to yield the 1,3,2-dioxaphospholanium or 1,3,2-oxathiophospholanium ion. Product ion structures were investigated by CID tandem mass spectrometry (MS(2)) experiments and corroborated by DFT/HF calculations.
Collapse
Affiliation(s)
- Eduardo C Meurer
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | | | | | | | | |
Collapse
|