Transannular Interaction in N-Aryl-5-Azocanones, A Semiempirical Quantum Mechanics and UV Spectroscopy Studies

The ability of the present semiempirical quantum mechanics methods are surveyed for reproducing the transannular interaction in the bifunctional N-phenyl-5-azocanones. The AM1 method is the best with the order of reliability being Am1, PM3, MNDO and MINDO/3. AM1 calculations were then carried out for quantification of transannular interaction. The n(o) ionization potential has been used for this purpose. A linear correlation is found between the n(o) ionization potential and the Hammett substituent constant (s). The UV spectroscopy was used to study the transannular bond formation N-aryl-5-azocanone derivatives.