Syntheses and study on nickel(II) complexes with thiodiglycolic acid and nitrogen-donor ligands.: X-ray structures of [Ni(bpy)(tdga)(H2O)•4H2O and [(en)Ni(μ-tdga)2NI(en)]•4H2O (tdgaH2= thiodiglycolic acid)

Mixed-ligand Ni(II) complexes involving thiodiglycolate(2-) anion (tdga) and nitrogen-donor ligands in the coordination sphere have been prepared. The complexes of composition [Ni(bpy)(tdga)(H2O)].4H(2)O (1), [(en)Ni(mu-tdga)(2)Ni(en)].4H(2)O (2), [Ni(phen)(tdga)(H2O)] (3), [Ni(1,8-dan)(tdga)(H2O)] (4), [Ni(nphen)(tdga)(H2O)].H2O (5), [Ni(ampy)(tdga)(H2O)] (6), where bpy = 2,2'-bipyridine,en = ethylenediamine,phen = 1,10-phenanthroline, 1,8-dan = 1,8-diaminonaphthalene, nphen = 5-nitro-1,10-phenanthroline and ampy = 2-(aminomethyl)-pyridine, have been characterized by elemental analysis, IR and UV-Vis spectroscopies, and magnetic susceptibility measurements. Room temperature effective magnetic moments for 1-6 are ranging from 3.06 to 3.28 mu(eff)/mu(B). and thus indicating that nickel atoms are six-coordinated in a deformed octahedral arrangement in all the prepared complexes. This conclusion has been confirmed by single-crystal X-ray analysis of [Ni(bpy)(tdga)(H2O)].4H(2)O (1). A binuclear structure of complex [(en)Ni(mu-tdga)(2)Ni(en)].4H(2)O (2) has been anticipated in connection with study of its magnetic properties over the 1.8-300 K temperature range (J = 4.35 cm(-1), D = 5.53 cm(-1), zJ = -0.94 cm(-1) for g = 2.00) and unambiguously proved by a single-crystal X-ray analysis. (C) 2004 Elsevier Ltd. All rights reserved.