A study of the photochemical behaviour and relaxation mechanisms of anti-syn isomerisation around quinazolinone -N-N[double bond, length as m-dash] bonds.

ABSTRACT: High-resolution NMR experiments revealed that differently substituted quinazolinone-based Schiff bases undergo anti to syn isomerisation on exposure to ultraviolet light in DMSO solution. The degree anti to syn conversion varied significantly upon substitution (between 5% and 100%) and also showed two noteworthy features: that relaxation back to the anti-form goes far faster (by at least 3 orders of magnitude) when the C₆ rings B and C have ortho-OH substituents, and that relaxation can also be significantly sped up by addition of acid. Two possible mechanisms explaining the differences in relaxation process have been proposed: (I) the interaction of the azomethine hydrogen with the carbonyl oxygen results in slower reversion to the a

SUBMITTER: Hricovini M 

PROVIDER: S-EPMC9524441 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature