Meso-functionalized octamethoxyporphyrins: A new class of nonasubstituted porphyrins

Abstract

Octamethoxyporphyrin containing multiple-donor substituents bas been functionalized for the first time. A large number of its mono-meso-substituted derivatives with substituents such as nitro, amino, N-methylamino, formyl, hydroxymethyl, oxime, cyano and carboxy functional groups have been synthesized and characterized. They form a new class of nonasubstituted porphyrins. Crystallographic studies on the cyano derivative show that the -C≡N group is in conjugation with the prophyrin π-system. The calculated optical transition energies and the electron densities on the imino nitrogens of the synthesised porphyrins using AMI calculations correlate well with the experimentally observed data. Mesosubstituted porphyrins are found to be essentially planar. © Indian Academy of Sciences.