Structures and Spectroscopic Properties of Bis(phthalocyaninato) Yttrium and Lanthanum Complexes: Theoretical Study Based on Density Functional Theory Calculations

Density functional theory (DFT) calculations were carried out to describe the molecular structures, molecular orbitals, atomic charges, UV−vis absorption spectra, IR, and Raman spectra of bis(phthalocyaninato) rare earth(III) complexes M(Pc)2 (M = Y, La) as well as their reduced products [M(Pc)2]- (M = Y, La). Good consistency was found between the calculated results and experimental data. Reduction of the neutral M(Pc)2 to [M(Pc)2]- induces the reorganization of their orbitals and charge distribution and decreases the inter-ring interaction. With the increase of ionic size from Y to La, the inter-ring distance of both the neutral and reduced double-decker complexes M(Pc)2 and [M(Pc)2]- (M = Y, La) increases, the inter-ring interaction and splitting of the Q bands decrease, and corresponding bands in the IR and Raman spectra show a red shift. The orbital energy level and orbital nature of the frontier orbitals are also described and explained in terms of atomic character. The present work, representing th...