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Gas‐phase reactivity of the OP(OCH 3 ) 2 + phosphonium ion with aliphatic esters in a quadrupole ion trap. Spontaneous elimination of ketenes
Author(s) -
Leclerc Eric,
Taphanel MarieHélène,
Morizur JeanPierre
Publication year - 2002
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.347
Subject(s) - chemistry , phosphonium , ketene , adduct , fragmentation (computing) , ion , propionate , mass spectrometry , methyl acetate , medicinal chemistry , electron ionization , reactivity (psychology) , molecule , chemical ionization , ion trap , photochemistry , organic chemistry , ionization , medicine , alternative medicine , chromatography , pathology , computer science , acetic acid , operating system
Ion–molecule reactions between the OP(OCH 3 ) 2 + phosphonium ions and five aliphatic esters (methyl acetate, methyl propionate, methyl 2‐methylpropionate, methyl butyrate and ethyl acetate) were performed in a quadrupole ion trap mass spectrometer. The OP(OCH 3 ) 2 + phosphonium ions, formed by electron ionization from neutral trimethyl phosphite, were found to react with aliphatic esters to give an adduct ion [RR′CHCOOR″, OP(OCH 3 ) 2 ] + , which loses spontaneously a molecule of ketene CH 2 CO or substituted ketenes RR′CCO. Isotope‐labeled methyl acetate was used to elucidate fragmentation mechanisms. The potential energy surface obtained from B3LYP/6–31G(d,p) calculations for the reaction between OP(OCH 3 ) 2 + and methyl acetate is described. Copyright © 2002 John Wiley & Sons, Ltd.