A. Marzotto, D. A. Clemente, Thomas Gerola
Apr 30, 2001
Citations
2
Influential Citations
38
Citations
Journal
Polyhedron
Abstract
Abstract The crystal and molecular structure of sodium 5-sulfosalicylate dihydrate, Na[(H2Ssal)(H2O)2], (1) (H3Ssal=5-sulfosalicylic acid) has been determined through X-ray diffraction analysis. The 5-sulfosalicylate anion has lost the proton at the SO3H group but retains the usual intermolecular hydrogen bond between phenolic and carboxylic oxygen. The reaction in water of 1 with [Cu(II)(H2O)4]SO4·H2O, gives rise to the green sodium[triaqua(5-sulfosalicylato)copper(II)] 2 hemihydrate, Na[(H2O)3(Ssal)Cu(II)]·2×0.5H2O, (2). The 5-sulfosalicylate anion, (Ssal3−), coordinates rather unusually in the syn–syn coordination mode since it binds bidentately the Cu(II) ion through the carboxylic and the phenolic oxygens, with Cu(II)Ocarboxylic=1.909(4) A and Cu(II)Ophenolic=1.885(4) A distances. Copper(II) completes its square-planar coordination with two water molecules and in addition, perpendicularly to the square-planar coordination plane, another two water molecules with long bonds are present (Cu(II)O=2.518 and 2.912 A). The green complex 2 reacts easily with adenine in water at pH 7 giving rise to the violet tetraadeninato(diaqua)-bis(copper(II)) dihydrate, [Cu2(Ade)4(H2O)2])]·2H2O, (3) (Ade−=adeninato monoanion). This complex, that geometrically resembles copper(II) acetate monohydrate, was already described by Sletten. Finally, on the basis of the present results a possible mechanism for the anticancer activity of complex 2 and of other Cu(II)–salicylate complexes is proposed and discussed.