Regio-isomeric effects in tandem mass spectra of sulfonium cations generated from thiacyclane based sulfonium salts under soft ionization conditions. Issue 1 (February 2018)

• Record Type: Journal Article
• Authors: Zaikin, Vladimir G; Kozlov, Anton V; Borisov, Roman S; Shchapin, Igor Yu
• Is Part Of: European journal of mass spectrometry. Volume 24:Issue 1(2018)
• Page Start: 108
• Page End: 115
• Publication Date: 2018-02
• Subjects: Mass spectrometry -- collision-induced dissociation -- electrospray -- matrix-assisted laser desorption/ionization -- sulfonium salts -- thiacyclanes -- regio-isomers; Mass spectrometry -- Periodicals; Mass Spectrometry; Mass spectrometry; Periodicals; Periodicals; 543.6505
• DOI: 10.1177/1469066717723909
• Languages: English
• ISSNs: 1469-0667

Abstract

The influence of regio-isomerism of even-electron sulfonium ions on tandem electrospray and matrix-assisted laser desorption/ionization mass spectra recorded by using collision-induced dissociation was investigated. The initial organic sulfides belonged to isomeric thiabicyclane series (substituted 7- and 8-thiabicyclo[4.3.0]nonanes, 2- and 3-thiabicyclo[4.4.0]decanes) and phenylthiolanes. To investigate by the abovementioned mass spectrometry methods, the sulfides were preliminary S-alkylated by methyl, ethyl iodides, their deuterated analogs and trialkoxonium tetrafluoroborates to form corresponding sulfonium salts. The latter salts readily gave off corresponding sulfonium cations under abovementioned desorption/ionization conditions and these cations were precursor ions in collision-induced dissociation experiments. The main quantitative and frequently qualitative differences between collision-induced dissociation spectra of isomers were manifested in mass numbers and relative intensities of the ions Alk-S + = CHR (formal structure) that originated from the destruction of sulfur-containing ring. Corresponding peaks are particularly abundant for cations Alk-S + = CH2 and their intensities are usually greater than for other C-substituted homologues. Qualitative difference between fragmentation features of 2- and 3-phenylthiolanium cations is that only the latter can eliminate neutral C2 H4 S molecule.