Abstract
The crystal structure of Co(NCS)2[4-vinylpyridine]4 has been determined by X-ray diffraction methods. The complex crystallizes in space group Pbca, with a = 32.293(15) Å, b = 11.416(6) Å, c = 17.033(10) Å, and Z = 8. Full-matrix least-squares refinement of positional and thermal parameters for all atoms (H atoms fixed at calculated positions), with 1458 reflections (F >; 3.92 σ(F)) led to R = 0.075 and Rw = 0.079. The trans-octahedral complex consists of four vinylpyridine ligands, arranged in a propeller-shape, and two isothiocyanate ligands. Powder diffraction of Co(NCS)2(4-vinylpyridine)2 indicates an isomeric cell, with a = 13.77 Å. The analogous Ni(II) complexes are isomorphous with the Co(II) complexes, suggesting that the yellow–green complex Ni(NCS)2(4-vpy)2, previously thought to be polymeric, is in fact tetrahedral.