Mass Spectrometric Behaviour of (Z)-2-Chloro-3(Dichloromethyl)-4-Oxobutenoic Acid and (Z)-2-Chloro-3(Chloromethyl)-4-Oxobutenoic Acid (Open Forms of MX and CMCF Respectively) Molecular Ions

Abstract

Fragmentation pathways of ( Z)-2-chloro-3(dichloromethyl)-4-oxobutenoic acid (MX open form) and ( Z)-2-chloro- 3(chloromethyl)-4-oxobutenoic acid (CMCF open form) are discussed on the basis of recorded metastable ions and high-resolution data. It was found that the presence of the additional chlorine atom in the chloromethyl group affects the fragmentation pathways of MX. The elimination of the dichloromethyl radical was observed for the MX+• ion but elimination of the chloromethyl radical does not occur for the CMCF+• ion. For the latter compound, elimination of a CO molecule was registered. The elimination of an HCl molecule occurs for both ions.