Metal(II) complexes with monodentate S and N ligands as structural models for zinc–sulfur DNA-binding proteins
摘要:
The reaction of several metal salts with various amounts of the monodentate ligands N-(2-thiophenyl)-2,5-dimethylpyrrole (H-tpdp) and N-methylimidazole in the presence of a base provided a series of novel complexes. They are of the general formulas [M-II(tpdp)(4)](2-)[M-II(tpdp)(2)(N-MeIm)(2)] (M = Zn, Co, Cd) and [M-II(tpdp)(3)(N-MeIm)](-) (M = Zn, Co). The products were characterized by X-ray structure analyses as well as by elemental analyses and infrared spectroscopy, and for the cobalt complexes by additional UV-Vis spectroscopy. Crystallographic parameters: [Et3NH](2)[Zn(tpdp)(4)]. MeCN (1), [Et3NH](2)[Co(tpdp)(4)]. MeCN (2), [Zn(tpdp)(2)(N-MeIm)(2)] (6) and [Co(tpdp)(2)(M-MeIm)(2)] (7) are monoclinic, space group P2(1)/c, with Z = 4; [Cd(tpdp)(2)(N-MeIm)(2)] (8) is monoclinic, space group P2(1)/n, with Z = 4; [Ph4P](2)[Cd(tpdp)(4)] (3), [Me4N] [Zn(tpdp)(3)(N-MeIm)] (4), and [Me4N][Co(tpdp)(3)(N-MeIm)] (5) are triclinic, space group P (1) over bar, with Z = 2. All compounds have tetragonally compressed metal cores. The complexes are significant as models for many zinc-containing DNA-binding proteins. (C) 1999 Elsevier Science S.A. All rights reserved.