THE CRYSTAL-STRUCTURE OF BIS(2,2' 6',2TERPYRIDINE)NICKEL(II) PERCHLORATE HYDRATE/

The crystal structure of bis(2,2':6',2 ''-terpyridine)nickel(II) bis(p erchlorate) hydrate has been determined by single-crystal X-ray diffra ctometry. The compound is monoclinic, space group P2(1), with two mole cules in a unit cell of dimensions a 8.827(4), b 8.910(2), c 20.148(9) Angstrom, beta 98.71(2)degrees. The structure was refined by least-sq uares to a residual of 0.065 for 2184 observed reflections. The compou nd is found to be isomorphic with the iron(II) analogue previously rep orted: the cation has approximate D-2d symmetry, with the main distort ion from octahedral symmetry being an axial compression. Both the soli d state reflectance and solution spectra have been measured and some s ignificant differences are noted.