tert.-butylpentafluorophenylmethylchlorosilane as a reagent for the formation of hydrolytically stable alkylsilyl derivatives with electron-capturing properties

Mass Spectrometric Fragmentation of Trimethylsilyl and Related Alkylsilyl Derivatives

“…tert ‐Butyl(pentafluorophenyl)methylsilyl derivatives of alcohols, phenols, carboxylic acids, thiols and amines have been found to be suitable for gas chromatography with electron‐capture detection and GC/MS and were found to be many‐fold more stable towards hydrolysis than the flophemesyl derivatives (Poole et al, ). Their spectra showed features of both TBDMS and flophemesyl derivatives in that molecular ions were of low abundance but very abundant [M − tert ‐C 4 H 9 • ] + ions ([M − 57] + ) were present.…”

“…found to be suitable for gas chromatography with electroncapture detection and GC/MS and were found to be manyfold more stable towards hydrolysis than the flophemesyl derivatives (Poole et al, 1980a). Their spectra showed features of both TBDMS and flophemesyl derivatives in that molecular ions were of low abundance but very abundant [M − tert-C 4 H 9…”

Diagnostic Fragmentation of Saturated and Unsaturated Fatty Acids by Gas Chromatography–Mass Spectrometry with Pentafluorophenyldimethylsilyl Derivatization

“…Consequently, glycine causes synthesis of a defective but a "leaky" or more permeable cell wall, allowing selective discharge of periplasmic contents (6). Glycine supplementation in the medium has been reported to increase the electroporation efficiency of bacteria (7,8). Here we report that glycine supplementation imparts to E. coli an ability to be transformed with exogenous DNA with significantly enhanced frequencies reaching values close to those obtained by electroporation, thus alleviating the need for…”

“…Also, the flophemesyl derivatives are characterized by m/z 58 and 77. Another significant ion is the m/z 121, which is given by the elimination of the F 2 at the fluorohydrocarbon tropylium ion (m/z 159) (7).…”

Derivatization reactions in the gas—liquid chromatographic analysis of drugs in biological fluids

“…However, some reagents have been developed that appear to be more resistant to hydrolysis. For example, tert-butyldimethylsilylated compounds are more stable than their TMS counterparts; rerr-buflophemesyl derivatives are much more stable towards hydrolysis than the flophemesyl derivatives, allowing partitioning of these compounds in liquid-liquid systems of an organic solvent and an acidic or basic aqueous solution [108]. Silylating reagents and their derivatives contaminate the FID detectors with silica deposits on the electrodes, changing the sensitivity of the detector or the response factors.…”