Mass spectra of 1,3,5-triarylpentane-1, 5-diones: formation and decomposition of pyrilium cation from the molecular ion

Abstract

Electron impact mass spectra of 1,3,5-triarylpentane-1,5-diones are reported. All compounds studied show a tendency to eliminate a water molecule and also the elements of [H3O] before fragmentation to smaller ions. The [H3O] loss proceeds via loss of water to form a pyran ion, which subsequently eliminates a hydrogen atom to form the stable pyrillium cation.