Copper(II) 3,5-Dinitrosalicylate – The Unique System for Co-crystal Formation by Gentle Changes in Preparation Procedure
Milan Gembický a, Ján Moncoľ, Katarína Lebrušková, Ladislav Martiška , Dušan Valigura *
Department of Inorganic Chemistry, Slovak Technical University, Radlinského 9, SK-812 37 Bratislava, Slovakia
a Department of Chemistry State University of New York at Buffalo,
E-mail: * dusan.valigura@stuba.sk
Abstract: Reactions of copper(II) salts with 3,5-dinitrosalicylic acid in presence of zinc(II), or manganese(II) salts yield to the complexes (1) or (2) formation. The composition of complexes found from X-ray structural analysis show that the co-crystals of composition [Cu3{3,5-(NO2)2sal2–}2{3,5-(NO2)2sal1–}2(H2O)4]x[Cu{3,5-(NO2)2sal1–}2(H2O)2]2(1–x)·4H2O (3,5-(NO2)2salz– = 3,5-dinitrosalicylate(z–) anion, x = 0.420(2) for (1) and x = 0.225(2) for (2)) were obtained. The crystal structures have been determined and refined to R = 0.042 (wR = 0.092), and R = 0.039 (wR = 0.087) for complex (1) and (2), respectively. The complexes crystallizes in monoclinic system, space group P21/c, and the structure of the complexes comprise of the centrosymmetric trimeric [Cu3{3,5-(NO2)2sal2–}2{3,5-(NO2)2sal1–}2(H2O)4] molecules, that are to the extent x replaced by pairs of monomeric [Cu{3,5-(NO2)2sal1–}2(H2O)2]. The water molecules complete structures by system of different types of hydrogen bonds. The Cu2 atom in [Cu3{3,5-(NO2)2sal2–}2{3,5-(NO2)2sal1–}2(H2O)4] is centrosymmetrically coordinated by two 3,5-dinitrosalicylato dianion thus forming the square planar CuO4 chromophore. Each of the satellite Cu1 atoms are coordinated by one oxygen atom of bridging 3,5-dinitrosalicylato dianion, two oxygen atoms of chelating 3,5-dinitrosalicylato monoanion (in the phenolato form), and by two water oxygen atoms in the square pyramidal coordination polyhedron. The Cu1 atoms in monomeric molecules are coordinated by one oxygen atom of monodentately coordinated 3,5-dinitrosalicylato monoanion, by two oxygen atoms of chelating 3,5-dinitrosalicylato monoanion, and by two water oxygen atoms to form the square pyramidal coordination polyhedron.
Keywords: copper complex, co-crystal, crystal structure, salicylato ligand
Full paper in Portable Document Format: acs_0025.pdf
Acta Chimica Slovaca, Vol. 1, No. 1, 2008, pp. 290—300