X-ray studies, spectroscopic characterisation and DFT calculations for Mn(II), Ni(II) and Cu(II) complexes with 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine

Abstract

New complexes with formula [M(SCN)2(L)2] where M = Mn(II), Cu(II) were synthesized in simple reactions of metal chlorides with ammonia thiocyanate and 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine (pytz) ligand in methanol solutions. In the reaction of NiCl2 6H2O and pytz ligand the [NiCl2(pytz)2] 2CH3OH complex was obtained. The complexes were studied by IR, UV–vis, EPR spectroscopy and X-ray crystallography. Electronic structures of the complexes were calculated using DFT method, and apart from the descriptions of frontier molecular orbitals and the relocation of the electron density of the compounds, the bonding properties in the complexes were determined.