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Fast atom bombardment mass spectrometry of some alkoxv‐ and chloro‐silanes
Author(s) -
Kallury Krishna M. R.,
Krull Ulrich J.,
Thompson Micliael
Publication year - 1991
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210260206
Subject(s) - silanes , chemistry , siloxane , hydrolysis , mass spectrum , ion , alkoxy group , fast atom bombardment , medicinal chemistry , mass spectrometry , spectral line , analytical chemistry (journal) , crystallography , organic chemistry , silane , alkyl , chromatography , physics , astronomy , polymer
The positive and negative FAB mass spectra of a series of alkoxy‐ and chloro‐silanes X m (CH 3 ) 3 ‐ m Si(CH 2 ) n R [ m = 1 or 3, n = 3, 10 or 17, X = Cl or OMe or OEt, R = Me, NH 2 , glycidoxy, COOMe, NHCO(CH 2 ) 7 COOMe or NHCO(CH 2 ) 10 CH 2 OAc] were recorded in NBA and NPOE matrices. The chlorosilanes underwent rapid hydrolysis into silanols which condense to form siloxanes, the process being complete in NBA and partial in NPOE, yielding siloxane‐based fragment ions in the positive spectra and silyloxyanions in the negative spectra. The alkoxysilanes were more resistant to hydrolysis, affording abundant [MH – HX] + ions (X = OMe or OEt) in their positive FAB spectra and moderate to high intensity [M – H] − ions in the negative mode, the latter undergoing characteristic sequential loss of C 2 H 4 , EtOH and C 2 H 4 . Significant variations were observed in the positive spectra of all the silanes with change of matrix.