Solution-solid-state study of the system Cu(II)/N-2-(4-amino-1,6-dihydro-1-methyl-5-nitroso-6-oxopyrimidinyl)glycine.: Mononuclear and polynuclear ladder-like chain complex crystalline structures

An aqueous solution-solid-state study of the Cu(II)/HL system (HL=N-2-(4-amino-1,6-dihydro-1-methyl-5-nitroso-6-oxopyrimidinyl)glycine) is reported. The solution studies have been carried out on the protonation equilibria of HL and the Cu(II)/HL system, at molar ratios of 1:1 and 1:5. Two complexes were obtained in the solid state, Cu(II)/HL molar ratio=1:1, and were characterized by spectroscopic and X-ray single-crystal diffraction techniques. Mononuclear complex 1 [(CuCl2(HL)(2)](n) crystallizes with a hexacoordinated coordination mode around the Cu(II) ion, while complex 2 [CuCl(L)(H2O)(2)] is an infinite polynuclear ladder-like chain, with a distorted asymmetric square-based bipyramid. None of those crystalline complexes were detected in the solution study. (C) 1999 Elsevier Science Ltd. All rights reserved.