Bethany Lowe, Alejandro L. Cardona, Juana Salas, Andras Bodi, Paul M. Mayer, Maxi A. Burgos Paci
{"title":"一氯之差:甲酸苯酯和氯甲酸苯酯的非凡单分子离子化学。","authors":"Bethany Lowe, Alejandro L. Cardona, Juana Salas, Andras Bodi, Paul M. Mayer, Maxi A. Burgos Paci","doi":"10.1002/jms.5004","DOIUrl":null,"url":null,"abstract":"<p>Imaging photoelectron photoion coincidence (iPEPICO) spectroscopy and tandem mass spectrometry were employed to explore the ionisation and dissociative ionisation of phenyl formate (PF) and phenyl chloroformate (PCF). The threshold photoelectron spectra of both compounds are featureless and lack a definitive origin transition, owing to the internal rotation of the formate functional group relative to the benzene ring, active upon ionisation. CBS-QB3 calculations yield ionisation energies of 8.88 and 9.03 eV for PF and PCF, respectively. Ionised PF dissociates by the loss of CO via a transition state composed of a phenoxy cation and HCO moieties. The dissociation of PCF ions involves the competing losses of CO (<i>m</i>/<i>z</i> 128/130), Cl (<i>m</i>/<i>z</i> 121) and CO<sub>2</sub> (<i>m</i>/<i>z</i> 112/114), with Cl loss also shown to occur from the second excited state in a non-statistical process. The primary CO- and Cl-loss fragment ions undergo sequential reactions leading to fragment ions at <i>m</i>/<i>z</i> 98 and 77. The mass-analysed ion kinetic energy (MIKE) spectrum of PCF<sup>+</sup> showed that the loss of CO<sub>2</sub> occurs with a large reverse energy barrier, which is consistent with the computationally derived minimum energy reaction pathway.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"59 2","pages":""},"PeriodicalIF":1.9000,"publicationDate":"2024-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"What a difference a chlorine makes: The remarkable unimolecular ion chemistry of phenyl formate and phenyl chloroformate\",\"authors\":\"Bethany Lowe, Alejandro L. Cardona, Juana Salas, Andras Bodi, Paul M. Mayer, Maxi A. Burgos Paci\",\"doi\":\"10.1002/jms.5004\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Imaging photoelectron photoion coincidence (iPEPICO) spectroscopy and tandem mass spectrometry were employed to explore the ionisation and dissociative ionisation of phenyl formate (PF) and phenyl chloroformate (PCF). The threshold photoelectron spectra of both compounds are featureless and lack a definitive origin transition, owing to the internal rotation of the formate functional group relative to the benzene ring, active upon ionisation. CBS-QB3 calculations yield ionisation energies of 8.88 and 9.03 eV for PF and PCF, respectively. Ionised PF dissociates by the loss of CO via a transition state composed of a phenoxy cation and HCO moieties. The dissociation of PCF ions involves the competing losses of CO (<i>m</i>/<i>z</i> 128/130), Cl (<i>m</i>/<i>z</i> 121) and CO<sub>2</sub> (<i>m</i>/<i>z</i> 112/114), with Cl loss also shown to occur from the second excited state in a non-statistical process. The primary CO- and Cl-loss fragment ions undergo sequential reactions leading to fragment ions at <i>m</i>/<i>z</i> 98 and 77. The mass-analysed ion kinetic energy (MIKE) spectrum of PCF<sup>+</sup> showed that the loss of CO<sub>2</sub> occurs with a large reverse energy barrier, which is consistent with the computationally derived minimum energy reaction pathway.</p>\",\"PeriodicalId\":16178,\"journal\":{\"name\":\"Journal of Mass Spectrometry\",\"volume\":\"59 2\",\"pages\":\"\"},\"PeriodicalIF\":1.9000,\"publicationDate\":\"2024-02-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Mass Spectrometry\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/jms.5004\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"BIOCHEMICAL RESEARCH METHODS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Mass Spectrometry","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/jms.5004","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOCHEMICAL RESEARCH METHODS","Score":null,"Total":0}
What a difference a chlorine makes: The remarkable unimolecular ion chemistry of phenyl formate and phenyl chloroformate
Imaging photoelectron photoion coincidence (iPEPICO) spectroscopy and tandem mass spectrometry were employed to explore the ionisation and dissociative ionisation of phenyl formate (PF) and phenyl chloroformate (PCF). The threshold photoelectron spectra of both compounds are featureless and lack a definitive origin transition, owing to the internal rotation of the formate functional group relative to the benzene ring, active upon ionisation. CBS-QB3 calculations yield ionisation energies of 8.88 and 9.03 eV for PF and PCF, respectively. Ionised PF dissociates by the loss of CO via a transition state composed of a phenoxy cation and HCO moieties. The dissociation of PCF ions involves the competing losses of CO (m/z 128/130), Cl (m/z 121) and CO2 (m/z 112/114), with Cl loss also shown to occur from the second excited state in a non-statistical process. The primary CO- and Cl-loss fragment ions undergo sequential reactions leading to fragment ions at m/z 98 and 77. The mass-analysed ion kinetic energy (MIKE) spectrum of PCF+ showed that the loss of CO2 occurs with a large reverse energy barrier, which is consistent with the computationally derived minimum energy reaction pathway.
期刊介绍:
The Journal of Mass Spectrometry publishes papers on a broad range of topics of interest to scientists working in both fundamental and applied areas involving the study of gaseous ions.
The aim of JMS is to serve the scientific community with information provided and arranged to help senior investigators to better stay abreast of new discoveries and studies in their own field, to make them aware of events and developments in associated fields, and to provide students and newcomers the basic tools with which to learn fundamental and applied aspects of mass spectrometry.