Negative-ion chemical ionization of phenothiazines with oxygen

Abstract

When O2 is used as a reagent gas for negative‐ion chemical ionization (NCI) of phenothiazines and related compounds, the majority of the ions observed are formed by surface‐catalyzed reactions prior to ionization. Both oxidation of the sulfur atom and formation of quinoid systems are observed. Alkyl derivatives also show degradation in addition to loss of the substituent. Deuterium labeling studies allowed several of the reaction paths to be elucidated. Copyright © 1999 John Wiley & Sons, Ltd.