Synthesis and molecular structure of polymeric bis(N-methylthiourea-κS)bis(thiocyanato-κN)nickel(II), [Ni(Metu)2(NCS)2] ; DFT analysis of [Ni(Metu)2(NCS)2] and [Ni(Thiourea)2(NCS)2]

A Nickel(II) complex, catena-poly[bis(N-methylthiourea)bis(thiocyanato-κN)nickel(II)], [Ni(Metu)2(NCS)2]n (1) was prepared and its structure was determined by single crystal X-ray analysis. In 1, the nickel(II) ion is bound to four sulfur atoms of bridging Metu ligands and two nitrogen atoms of thiocyanate adopting a distorted octahedral environment. The crystal structure is stabilized by both intra and intermolecular hydrogen bonding interactions. The complex was also characterized by IR spectroscopy and the spectroscopic data is discussed in terms of the nature of bonding. The structures of [Ni(Metu)2(NCS)2]n (1) and its analogous thiourea (Tu) complex, [Ni(Tu)2(NCS)2]n (2) were predicted by DFT calculations. The IR frequency calculations were performed using DFT/B3LYP-D3 methodology. The atomic charges and spin densities were calculated using natural bond orbital (NBO) analysis for complexes 1 and 2.