Structures and properties of 2,3,9,10,16,17,23,24-octasubstituted phthalocyaninato-lead complexes: The substitutional effect study on the basis of density functional theory calculations

Density functional theory (DFT) and time-dependent DFT calculations were carried out to comparatively describe the molecular structures, atomic charges, molecular orbital energy gaps, UV-vis spectra, infrared (IR) and Raman spectra of PbPc(R)8 (R = F, Cl, Br, H, -CH3, -C2H5, -C3H7) (1-7). Both the calculated structure and infrared spectrum of PbPc (4) are in good consistency with the experimental results. It has also been found that substitution of electron-withdrawing halogen groups and electron-donating alkyl groups at the peripheral positions of phthalocyanine ring add obvious and different effects to the structures and properties of phthalocyaninato lead compounds. The change rules of the parameters studied have no linear relationship with the Hammett constants of the substituents due to the complexity of phthalocyanine macrocycle.