Formation of Nickel(II) Coordination Polymers by a Double Betaine: [{Ni(L)(H2O) 2} n] Cl2n.2nH2O and [{Ni(L)2(H2O)2} n

Abstract

Two novel polymeric nickel(II) complexes of a double betaine with a rigidtris(ethylene) bridge between the pair of nitrogen atoms, namely [ {Ni(L)(H2O)4 }n]Cl2n.2nH2O(1)and [ {Ni(L)2(H2O)2} n](ClO4)2n.4nH2O(2) [L =¯O2CCH2N+(CH2CH2)3N+CH2CO2¯], have been prepared and characterized by X-ray crystallography. Thenickel(II) atom in either complex is coordinated by unidentate carboxylategroups and aqua ligands in a distorted octahedral geometry. The crystalstructure of (1) features an infinite zigzag chain composed of an alternatearrangement of metal atoms and double betaine ligands, and hydrogen bondingamong adjacent chains leads to a three-dimensional network. Complex (2)exhibits a wave-like layer structure corresponding to the (2 0 0) family ofplanes.