| Abstract: Density functional theory (DFT) calculations were carried out to describe the molecular structure, atomic charges, molecular orbital energy gaps, HOMO orbital map, and infrared (IR) spectrum of metal-free porphyrazine with annulated 1,2,5-thiadiazole and 1,4-diamyloxybenzene groups (cis-S2A2)PzH2 (A=the annulated 1,4-diamyloxybenzene ring, S=the 1,2,5-thiadiazole ring) in the peripheral position of the porphyrazine macr-ocycle. The calculated structure and IR spectrum of (S2A2)PzH2 are in good consistency with the experimental results. It has been found that the electron-withdrawing 1,2,5-thiadiazole groups and the electron-donating 1,4-diamyloxybenzene groups at the peripheral positions of porphyrazine ring add obviously different effect to different pyrrole and pyrrolenine rings. In addition, time dependent-DFT (TD-DFT) calculations were also performed on the electronic absorption spectrum of (S2A2Pz)Mg, the nature of the main transitions have been assigned accordingly. With the assistance of animated pictures produced on the basis of the normal coordinates, the vibration modes in the IR spectrum of (S2A2)PzH2 have also been identified. |
