Energy-variable collision-induced dissociation study of 1,3,5-trisubstituted 2-pyrazolines by electrospray mass spectrometry

Sándor Kéki, Lajos Nagy, János Török, Katalin Tóth, Albert Lévai, Miklós Zsuga

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The pathways of the ([M+H]+) ions generated from electrosprayed solutions of nine 1,3,5-trisubstituted 2-pyrazoline derivatives were studied using energy-variable collision-induced dissociation (CID) and pseudo-MS 3 (in-source CID combined with MS/MS) methods. It was shown that under CID conditions several structurally important product ions such as the 2,4-substituted azete and 1,2-substituted aziridine ions were formed. The compositions of the product ions were unambiguously supported by accurate mass measurement (mass accuracy was within ±8 ppm). The fragmentation pathways of 1,3,5-trisubstituted 2-pyrazolines were established by means of pseudo-MS3. It was found that a substituent at the N-1 position greatly affects the fragmentation pathways of the 2-pyrazoline derivatives. The 1-acetyl- and 1-propionyl-2-pyrazoline derivatives dissociate mainly through formation of a pyrazolium cation, while in the case of 1-phenyl-2-pyrazoline derivatives product ions arising from the consecutive fragmentation of 2,4-substituted azete and 1,2-substituted aziridine ions dominate. Another interesting finding is the formation of a radical cation from the 2,4-substituted azete by loss of a methyl radical. The fragmentation yield as a function of the collision energy for each of the 1,3,5-trisubstituted 2-pyrazolines was determined. Based on the fragmentation yield versus collision energy curves the relative fragmentation stabilities for the 1,3,5-trisubstituted 2-pyrazoline derivatives were also evaluated.

Original languageEnglish
Pages (from-to)1799-1808
Number of pages10
JournalRapid Communications in Mass Spectrometry
Volume21
Issue number11
DOIs
Publication statusPublished - Jun 1 2007

ASJC Scopus subject areas

  • Analytical Chemistry
  • Spectroscopy
  • Organic Chemistry

Fingerprint Dive into the research topics of 'Energy-variable collision-induced dissociation study of 1,3,5-trisubstituted 2-pyrazolines by electrospray mass spectrometry'. Together they form a unique fingerprint.

  • Cite this