Structural identification of alkene isomers by photodissociation–photoionization mass spectrometry

✍ Scribed by Scott E. Van Bramer; Murray V. Johnston

• Book ID: 102964771
• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 530 KB
• Volume: 27
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210270904

✦ Synopsis

Photodissociation-phtoionization, mass spectrometry (PDPIWS) is used to probe the wutral dissociation chemistry of branched alkenes and dienes. Molecules are pbotodkociated with an ultraviolet laser and the resulting neutral fragments are subsequently photoionized with coherent vacuum ultraviolet radiation. The neutral fragmentation observed is useful for characterizing compounds which isomerize prior to ionic fragmentation. Unimolecular photodisaciation of d i e m and branched alkeoes is dominated by cleavage of the fl C-C bond. In a few cases,

a-cleavage is also observed. When two isomers produce isomass primary products, secondary fragmentation can be used to distinguish the structures. The primary and secondary product distributions are predictable and lsually occur without iomerization. As a result, PDPI/MS can be used to determine the sites of branching and unsata ration in small (C,-C,) aliphatic compounds.