Formation of C6H7+ ions in ion–molecule reactions in vinyl chloride

Abstract

The formation of C6H7+ species in ion/molecule reactions in gaseous vinyl chloride was studied in a high pressure photoionization mass spectrometer and in a Fourier transform ion cyclotron resonance (FT-ICR) spectrometer. Collision-induced dissociation (CID) mass spectra of C4H5Cl+, C4H6Cl+, and C6H7+ species suggest a "butadiene-like" structure for the two former ions, and a non-benzenium structure for the last species. The C6H7+ ions are formed in a two-step mechanism involving C4H5+ as intermediate ions. These processes are in competition with condensation reactions leading to the formation of C6H7–9Cl+ species. Key words: ion–molecule reactions, gaseous vinyl chloride, collision-induced dissociation.