Synthesis, crystal structure and properties of catena-poly[[[bis(3-methylpyridine-κN)nickel(II)]-di-μ-1,3-thiocyanato] acetonitrile monosolvate

Abstract

In the crystal structure of the title compound, {[Ni(NCS)2(C6H7N)2]·CH3CN} n , the NiII cation is octa-hedrally coordinated by two N-bonding and two S-bonding thio-cyanate anions, as well as two 3-methyl-pyridine coligands, with the thio-cyanate S atoms and the 3-methyl-pyridine N atoms in cis-positions. The metal cations are linked by pairs of thio-cyanate anions into chains that, because of the cis-cis-trans coordination, are corrugated. These chains are arranged in such a way that channels are formed in which disordered aceto-nitrile solvate mol-ecules are located. This overall structural motif is very similar to that observed in Ni(NCS)2[4-(boc-amino)-pyridine]2·CH3CN reported in the literature. At room temperature, the title compound loses its solvent mol-ecules within a few hours, leading to a crystalline phase that is structurally related to that of the pristine material. If the ansolvate is stored in an aceto-nitrile atmosphere, the solvate is formed again. Single-crystal X-ray analysis at room-temperature proves that the crystals decompose immediately, presumably because of the loss of solvent mol-ecules, and from the reciprocal space plots it is obvious that this reaction, in contrast to that in Ni(NCS)2[4-(boc-amino)-pyridine]2·CH3CN, does not proceed via a topotactic reaction.