Synthesis, characterization, thermal and theoretical studies of cobalt(II) addition compounds with 2-hydroxy-phenones and α-diimines. Crystal and molecular structures of [Co(2-hydroxy-benzophenone)2(bipy)]·2- hydroxy-benzophenoneH (3) and [Co(2-hydroxy-benzophenone)2(phen)] (8)

摘要

Ten Co(II) addition compounds [Co(ketone)2Y], where ketone is the anion of 2-hydroxy-phenones and Y = the neutral α-diimines(bipy or phen), were synthesized and characterized by physicochemical and spectral (IR, UV-Vis) data. The molecular structures, vibrational and electronic spectra, and the energetics of the metal-ligand interactions for compounds [Co(2-hydroxy-benzophenone)2(bipy)]·2-hydroxy-benzophenoneH (3) and [Co(2-hydroxy-benzophenone)2(phen)] (8) were studied by means of density functional calculations (DFT). Good correlation was found between the theoretical calculations and the experimental values. The cyclic voltammetry study in CH_3CN gave all the expected waves for the redox processes of the metal Co(II) and the studied ligands. The X-ray diffraction study of the two compounds (3) and (8) verified their analogous proposed octahedral arrangement of the ligands around the cobalt(II) atom. The thermal behaviour was investigated by means of simultaneous TG/DTG-DTA technique in nitrogen atmosphere up to 1000 °C, where metallic cobalt was found as the solid residue.