Studies on the zinc(II)-azoimine system. Single-crystal X-ray structure of Zn(MeaaiMe)Cl-2 center dot H2O and Zn(HaaiMe)(2)(NCS)(2) (MeaaiMe=1-methyl-2-(p-tolylazo)imidazole, HaaiMe=1-methyl-2-(phenylazo) imidazole)

摘要

Dichloro zinc(II) complexes of 1-alkyl-2-(arylazo)imidazole, Zn(RaaiR')Cl-2.H2O (RaaiR'=p-R-C6H4-N = N-C3H2N-N(1)R': R = H, Me, Cl and R'= Me, CH2CH3, CH2Ph) are characterized by elemental analysis, IR, UV-Vis and H-1 NMR spectral data. The reaction of ZnCl2 and RaaiR' (excess) in the presence of NH4CNS has synthesized Zn(RaaiR')(2)(NCS)(2). The single-crystal X-ray structure of dichloro-{1-methyl-2-(p-tolylazo)imidazole)zinc(II)-monohydrate (Zn(MeaaiMe)Cl-2.H2O) suggests that the complex is distorted trigonal bipyramidal (TBP) around Zn(II) with a trigonal plane constituted from Cl(l), Cl(2), N(imidazole) (N(l)). Molecular packing shows a 1D chain via a hydrogen bonded eight membered ring. The X-ray structure of di-thiocyanatobis- {1-methyl-2-(phenylazo)-imidazole) zinc(II) also shows a distorted TBP around Zn(II). The coordination sphere is ZnN3 type: where one of the ligands acts as a bidentate chelating agent and the second one coordinates via only the imidazole-N along with two N-centers from the NCS group. (C) 2003 Elsevier Science Ltd. All rights reserved. [References: 26]