Theoretical study of novel azo-tetraphenylporphyrins: potential photovoltaic materials.

A density functional theory study was performed to analyze the electron donor-acceptor properties of the cis and trans isomers of a novel azobenzene-containing tetraphenylporphyrin (TPPN2PhC14H29) with different substituents (Br or TMS). In general, the trans isomers are better electron acceptors than the correspondent cis homologues. Their UV-vis spectra were also obtained and a comparison with available experimental results is included.