Synthesis, Isolation and X-ray Crystal Structure Characterization of Trans -γ-{(C- meso -5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane)(diisothiocyanato)} Nickel(II) Complex

摘要

A new isomer of [Ni(tet-a)](2+) (assigned as gamma-isomer) (tet-a = C-meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane), which is found in the complex of trans-gamma-[Ni(tet-a)(NCS)(2)], has been isolated from the reaction of beta-[Ni(tet-a)](ClO4)(2) with NaSCN in a mixture of MeOH-H2O (1:1, v/v) solution and characterized by X-ray crystallography. The complex crystallizes in orthorhombic Pca2(1) space group with the crystal cell parameters of a = 12.5787(10) angstrom, b = 11.6834(10) angstrom, c = 15.4019(12) angstrom, V = 2263.5(3) angstrom(3), and Z = 4. The crystal structure shows that the complex is noncentrosymmetric. The conformations of the six-asymmetric centers are assigned as 1R,4R,8S,11S,7R,14S or 1S,4S,8R,11R,7S,14R (Trans-III). The coordination polyhedron around the nickel atom is axially elongated octahedron with an N-6 chromophore. The association of the complex units through N(3)-H center dot center dot center dot S(1) (2.665 angstrom) hydrogen bonding interactions leads one-dimensional hydrogen bonded network along c-axis.