Download (4Mb) - Etheses - Saurashtra University

Part-IResults and DiscussionThe fragmentation pattern of the compound IVxxxiii is depicted in Scheme-26.Decomposition of molecular ion involves neutral loss of SO to give the daughter ion (a)at m/e 392. The daughter ion (a) further loses neutral CO molecule to give fragment (b) atm/e 363. Molecular ion also loses single oxygen atom to yield daughter ion (c) at m/e245. The prominent daughter ion (d) at m/e 180 is attributed to the starting material, 2-mercapto-5-methoxybenzimidazole as a radical cation. The fragmentation patterncompliance with the structure assigned to the compound (Table-10).O+.ONNSNHSNHO-[O]O-SOOIVxxxiiiO+.NN+.NSNH HNO aIVxxxiiia, M + , m/e 392ONScOIVxxxiiic, M + , m/e 245+ O+.O-CONN+.NSNH HNbIVxxxiiib, M + , m/e 363OScheme-26HSNHdIVxxxiiid, M + , m/e 180The fragmentation pattern of the compound IVxxxv is depicted in Scheme-27.Decomposition of molecular ion involves loss of thiomethyl and methyl radicals to givethe daughter ion (a) at m/e 404. The molecular ion also ejects an oxygen atom to givedaughter ion (b) at m/e 270. The prominent daughter ion (c) at m/e 180 is attributed to thestarting material, 2-mercapto-5-methoxybenzimidazole as a radical cation. Thefragmentation pattern compliance with the structure assigned to the compound (Scheme-27) (Table-10).112