Synthesis, structure and luminescence properties of cadmium(II) complexes with 2,4,6-tri(2-pyridyl)-1,3,5-triazine

The paper presents a combined experimental and computational study for two cadmium(II) complexes [Cd(dca)(NO3)(tptz)(H2O)]·2H2O (1) and [Cd(dca)(OAc) (tptz)(H2O)]·2H2O (2) (tptz=2,4,6-tri(2-pyridyl)-1,3,5-triazine and dca=dicyanamide anion). The compounds have been studied by IR, UV–vis spectroscopy and single crystal X-ray analysis. Due to the presence of multidentate N-donor ligand, coordinated water molecule and nitrate or acetate groups together with the lattice water molecules their crystal structures are dominated by the hydrogen-bonding interactions that give rise to the supramolecular architectures. The luminescent properties of compounds 1 and 2 have been studied in solution and solid state and compared with the free ligand. The studies revealed that the fluorescence of tptz ligand and complexes 1 and 2 was concentration and solvent dependent. To get detailed insight into the electronic structure and spectroscopic properties of [Cd(dca)(NO3)(tptz)(H2O)] and [Cd(dca)(OAc) (tptz)(H2O)], the density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were performed.