Structural and magnetic studies of a syn-anti carboxylate-bridged helix-like chain copper(II) complex

The preparation, magnetic properties, and crystal and molecular structure of [CuL(H 2 O)] n are described (L stands for the doubly deprotonated form of 1,3-dimethyl-5-((2-carboxyphenyl)azo)barbituric acid). The crystals are orthorhombic, of space group P2 1 2 121 , with cell constants a=8.171 (1) A, b=10.302 (3) A, c=17.006 (5) A, and Z=4. The structure was solved and refined to R=0.052. The copper(II) ions are in a distorted square-pyramidal environment