Spektroskopische Untersuchungen, IX./Spectroscopic Investigations, IX.

Abstract

The mass-spectrometric investigation of esters and thiolesters of benzoic, thiobenzoic, salicylic and thiosalicylic esters shows that an analytical distinction with aid of the ortho effect is only possible under certain conditions between 1,2-disubstituted aromatic compounds and the other constitutional isomers. Absent or small intensive signals of rearrangement-ions do not exclude such a constitution. The apparent anomalous behaviour of the S-methyl, S-tolyl and O-tolyl esters is rationalized by energy considerations. The influence of the enthalpy of formation of the neutral particles on the product distribution (α-cleavage/ortho effect) is discussed.