| Abstract: | 7-Phenacylxanthopterin and its para-substituted derivatives, which exist in the chelate rign form initially lose CO from pyrazine rings followed by a hydrogen atom. This ion can also be formed in the reverse order, but not for the 4-amino analogues. Fragmentation of the intramolecularly hydrogen bonded sidechain also occurs involving loss of a benzoyl or phenyl radical. Linear plots at 40 eV for the loss of the benzoyl radical were obtained for log (Z/Z0) against the Hammet σ constants not only for the fragmentation of the xanthopterins but also for that of the amino analogues. |
