Pseudohalide manganese(II) complexes of 2-hydroxymethylbenzimidazole – Synthesis, spectroscopy, X-ray structure and magnetic properties

Abstract

Three new manganese(II) complexes of 2-hydroxymethylbenzimidazole [Mn(hmbzim)2(NCS)2] (1), [Mn2(hmbzim)4(μ1,1-N3)2](NO3)2 (2) and [Mn(hmbzim)2(dca)2]n (3) were synthesized and characterised. On the basis of structural data, the influence of pseudohalide ions on a final complex structure and role of weak intermolecular interactions in creation of molecular architecture have been discussed. The structure 1 consists of the mononuclear molecules [Mn(hmbzim)2(NCS)2] assembled via O–H⋯S and N–H⋯S hydrogen bonds into three dimensional supramolecular network The reaction with using of sodium azide resulted in formation of 0D dimeric structure of 2, whereas the complex 3 incorporating dicyanamide ions displays two-dimensional coordination framework. Magnetic measurements revealed ferromagnetic coupling (J=0.82(1)cm−1) inside the dimer of 2 and weak antiferromagnetic coupling (J=−0.37(1) cm−1) in 2D lattice of 3. The complex 1 indicated a very small antiferromagnetic interaction between MnII ions transmitted in the crystal lattice.