DFT and TDDFT study of chemical reactivity and spectroscopic properties of M(TePh)2 [TMEDA] M=Zn, Cd, and Hg complexes

A series of complexes of the type M(TePh)2 [TMEDA], where M = Zn, Cd, or Hg and TMEDA: N, N′, N′-tetra methyl ethylene diamine, have been investigated by the means of density functional theory (DFT) and time-dependent density functional theory (TDDFT) with LANL2DZ basis set. The geometric parameters, related energies, spectroscopic properties, namely, infrared and UV–visible spectra, and reactivity descriptors of these complexes were computed. The calculated values of the structural parameters show a good agreement with the available experimental data. The calculation of the reactivity descriptors confirm that the complex Zn (TePh)2 [TMEDA] is the most active biologically. The latter is of potential medical importance, mainly due to the presence of zinc, which is required for proper functioning of human biological systems. The frequencies of metal-Te, in the infrared spectra, are in the terahertz region, which find applications in multitude of areas in science and engineering, ranging from imaging tissue in medicine to security systems. The wavelengths, in the UV–visible spectra, are in near ultraviolet and visible regions. Three types of charge transfer are distinguished: intra-ligands, metal–ligand, and ligand–metal charge transfers.