DFT/TD-DFT study on spectroscopic properties of zinc(II), nickel(II), and palladium(II) metal complexes with a thiourea derivative

The geometries, electronic structures, and spectral properties of three metal complexes Zn(C10H12N3OS)2 ( 1 ), Ni(C10H12N3OS)2 ( 2 ) and Pd(C10H12N3OS)2 ( 3 ) with N -2-pyridinylmorpholine-4-carbothioamide as a ligand were investigated by means of the DFT (density functional theory) and TD-DFT (time-dependent density functional theory) methods. Complex 1 has a distorted tetrahedral geometry, while complexes 2 and 3 present a distorted square-planar coordination environment. In the simulated range, the spectrum of complex 1 has five obvious absorption peaks and one of them has the strongest intensity. The latter two complexes have one more absorption peak and a shoulder with similar intensity. Moreover, the strongest peak of com­plexes 2 and 3 is blue-shifted as compared with that of complex 1 .