Thiophen chemistry. Part XIII. Mass spectra of substituted thiophens

Abstract

The mass spectra of thiry-two substituted thiophens are reported and discussed. The compounds fragment in a well defined manner on electron impact; fragmentation processes have been substantiated by exact mass measurements and appropriate metastable ions. All mass spectra exhibit pronounced molecular ions, while skeletal rearrangement ions are present in many of the spectra. In general, isomeric thiophens containing substituents in either the 2- or 3-position cannot be differentiated by mass spectrometry.