Syntheses and crystal structures of zinc(II) complexes with three kinds of priperidine carboxylic acids

摘要

Zinc(II) complexes with DL-piperidine-2-carboxylic acid (Hpipe-2), DL-piperidine 3-carboxylic acid (Hpipe-3), and piperidine-4-carboxylic acid (Hpipe-4):ZnCl_2(Hpipe 2)_2, ZnCl_2(Hpipe-3)_2(H_2O)_3, and ZnCl_2(Hpipe-4) have been prepared and characterized by means of IR spectra and thermal analysis. The crystal structures of [ZnCl_2(Hpipe-3)_2].3H_2O and [ZnCl_2(Hpipe-4)] have been determined by X-ray diffraction. The crystal of [ZnCl_2(Hpipe-3)_2].3H_2O is monoclinic with the space group P2_1/c. The zinc atom is in a tetrahedral geometry, ligated by two carboxylato oxygen atoms and two chlorine atoms. The crystal of [ZnCl_2(Hpipe-4)] is triclinic with space group P1. This complex consists of a binuclear molecule bridged by two carboxylato oxygen atoms. The zinc atom is in a tetrahedral geometry ligated by two carboxylato oxygen atoms and two chlorine atoms.