Influence of the central metal on the structural, electronic, and spectroscopic properties of naphthalocyanine complexes: density functional theory calculations

A series of metal naphthalocyanine complexes (M = TiO 2+ , Fe 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , Ru 2+ ) have been investigated using density functional theory (DFT) and time-dependent DFT methods in vacuo and in the solvent dimethylsulfoxide in order to evaluate the influence of the different metal atoms on the geometries and optical properties of their complexes. The optimized geometries for the complexes without an axial ligand exhibit planar conformations. Most of the absorption bands of the metal complexes are blue-shifted compared to those of the metal-free naphthalocyanine, both in vacuo and in the solvent. The various transition metals could gradually tune the electronic and spectroscopic properties of their naphthalocyanine complexes, which may provide valuable information for tuning the properties of naphthalocyanine complexes for various applications.