Coordination of a mesogenic Schiff-base with MnII, CoII, NiII, CuII and ZnII: Synthesis, spectral studies and crystal structures
摘要:
A novel mesogenic (nematic) Schiff-base, N,N'-di-4-(4'-pentyloxybenzoate)salicylidene diaminoethane, H(2)dpbsde (abbreviated as H2L5) was synthesized and its structure studied. The Schiff-base crystallizes in the non-centrosymmetric space group Pna2(1) with Z = 4, and the mesogenic isomorphous nickel and copper complexes, [NiL5](2) and [CuL5], in the centrosymmetric space group P2(1)/c with Z = 4. The (L-5)(2)-species coordinates to the metal ions through two phenolate oxygens and two azomethine nitrogens. Both the [NiL5](2) and [CuL5] complexes involve cis-MN2O2 planes; the former complex has a low-spin distorted square-pyramidal geometry with a Ni-Ni bonding of 3.337 angstrom and the latter, a square-planar geometry. (c) 2008 Elsevier Ltd. All rights reserved.