A NEW HYDROGEN-BONDED DINUCLEAR COMPLEX INVOLVING COPPER(II) IONS IN A PSEUDOTETRAHEDRAL N3O ENVIRONMENT - MOLECULAR AND CRYSTAL-STRUCTURE AND MAGNETIC AND SPECTROSCOPIC PROPERTIES

The preparation, spectroscopic and magnetic properties, and crystal structure of [CuLpy]2.0.5H2O are described (L stands for the dideprotonated form of 6-amino-1,3-dimethyl-5-((2-carboxyphenyl)azo)uracil and py stands for pyridine). Crystals are monoclinic, of space group P2(1)/c, with cell constants a = 9.740 (3) angstrom, b = 19.258 (7) angstrom, c = 10.361 (3) angstrom, beta = 108.57 (3)-degrees, and Z = 2. The structure was solved and refined to R = 0.059. The structure comprises discrete dinuclear entities resulting from pairwise association of mononuclear fragments via two extended bridging networks Cu-O-C-O...H-N-Cu, which comprise long hydrogen bonds. The geometry of each CuN3O chromophore is intermediate between square planar and tetrahedral. The magnetic study points to an antiferromagnetic (singlet) ground state. The magnitude of the magnetic interaction is discussed on the basis of structural data.