Two novel 1D chain bis(benzimidazole) Co(II) complexes, their crystal structures and magnetic properties
Abstrakt
Two cobalt(II) complexes with 2-[2-[2-(1H-benzimidazol-2-yl)ethylsulfanyl]ethyl]-1H-benzimidazole (tebb) of compositions [Co(tebb)Cl2](n) . nCH3OH [1] and [Co(tebb)Br2](n) . 3/2nCH3OH [2] have been prepared. Their poly-meric structures were determined by X-ray crystallography.
In both cases, the central cobalt(II) atoms are in tetrahedral vicinity. There are two halogen anions and two nitrogen atoms of neighboring benzimidazole rings coordinated to cobalt.
Methanol molecules are outside the coordination sphere and connected by hydrogen bonds to polymeric molecules. Magnetic properties of the complexes have been studied in the temperature range of 2-300 K.
The moderate values of the zero-field splitting parameters were determined, D = -7.2(2) cm(-1) for [1] and D = -3.7(1) cm(-1) for [2]. The theoretical calculations based on CASSCF/NEVPT2 method supported these findings.