Formation of copper(II) coordination polymers by a flexible double betaine: [{Cu(L)X2(H2O)} n ]·2nH2O [X=Cl, Br] and [{Cu(L)(H2O)4} n ](ClO4)2n ·2nH2O [L=−O2CCH (Me3N+)CH2CH2CH(Me3N+)CO 2 −

Abstract

Three polymeric copper(II) complexes of a flexible double betaine, namely, [{Cu(L)Cl2(H2O)}n]·2nH2O (1), [{Cu(L)Br2(H2O)}n]·2nH2O (2), and [{Cu(L)(H2O)4}n](ClO4)2n·2nH2O (3) [L=−O2CCH(Me3N+)CH2CH2CH(Me3N+CO2], have been prepared and characterized by singlecrystal X-ray analysis. Isomorphous complexes (1) and (2) crystallize in space groupC2/c (No. 15) witha=17.725(3),b=5.958(2),c=19.077(3) A, β=110.70(1)o,V=1881.4(4) A3, Z=4 anda=18.268(4),b=5.948(3),c=19.166(5) A, β=109.08(2)o,V=1964.7(9) A3, Z=4, respectively. Complex (3) belongs to space groupPĪ (No. 2) witha=6.203(1),b=9.293(2),c=12.035(2) A, α=86.56(2), β=87.33(3), γ=71.23(2)o,V=655.4(2) A3 and Z=1. The crystal structure of (1) and (2) features an infinite zigzag chain composed of an alternate arrangement of metal atoms and double betaines ligands, with each Cu(II) atom in a distorted CuX2O3 [X-Cl, Br] square-pyramidal geometry, and hydrogen bonding between adjacent chains leads to a layer structure concentrated the (200) family of planes. Complex (3) exhibits a layer structure corresponding to the (001) family of planes, in which neighboring chains constructed from the metal atoms and the double betaine ligands are cross-linked by hydrogen bonding between the aqua ligands. The Cu(II) atom is coordinated in a CuO6 octahedral geometry with Jahn-Teller distortion.