SYNTHESIS AND CHARACTERIZATION OF ZN(II), CD(II) AND HG(II) COMPLEXESWITH IMIDAZOLE DERIVATIVES - CRYSTAL-STRUCTURE OF 4-CARBOETHOXY-1-P-METHOXYPHENYL-IMIDAZOLE)ZINC(II)

Two imidazole-derivative ligands, 5-amino-4-carboethoxy-1-p-methoxyphe nyl-imidazole (L) and 5-amino-4-nitrile-1-p-methoxyphenylimidazole (L' ), have been prepared and their interactions with Zn(II), Cd(II) and H g(II) reported. For the L ligand a series of complexes of general form ulae MCl2Lx, where x=1 or 2, has been obtained while for the L' ligand only the Cd(II) complex fits with the general formulae. For this latt er ligand the corresponding Hg(Il) complexes were not isolated and a Z n(II) complex was obtained with the ligand in the protonated form All the complexes have been characterized by spectroscopic and thermal tec hniques. In addition, the crystal structure of the ZnCl2L2 complex is reported. The compound crystallized in the monoclinic system, space gr oup P-1, with cell constants a=8.7328(18), b=10.5494(21) and c=17.3269 (34) Angstrom, alpha=75.265(10), beta=81.094(17) and gamma=70.939(11)d egrees and Z=2. The structure was served and refined to R=0.056 (R-w=0 .031). The structure consists of discrete neutral ZnCl2L2 entities in which the L ligand coordinates through the N atom belonging to the imi dazole ring, the Zn(II) ion exhibiting a distorted tetrahedral geometr y.