Inomata Yoshie, Arai Yumiko, Yamakoshi Takao, Scott Howell F
Department of Chemistry, Faculty of Science and Technology Sophia University, 7-1 Kioicho,Chiyoda-ku, Tokyo 102-8554, Japan.
J Inorg Biochem. 2004 Dec;98(12):2149-59. doi: 10.1016/j.jinorgbio.2004.09.022.
Six cadmium(II) halide complexes with dl-piperidine-2-carboxylic acid (DL-Hpipe-2), dl-piperidine-3-carboxylic acid (DL-Hpipe-3), and piperidine-4-carboxylic acid (Hpipe-4), have been prepared and characterized by means of IR and Raman spectra and thermal analysis. The crystal structures of [CdCl2(DL-Hpipe-2)(H2O)], [CdBr2(DL-Hpipe-3)], and [CdCl2(Hpipe-4)] have been determined by X-ray diffraction. These three complexes have one-dimensional polymer structures bridged by halide atoms. The crystal of [CdCl2(DL-Hpipe-2)(H2O)] is orthorhombic with the space group Pca2(1). The cadmium atom is in an octahedral geometry, ligated by a carboxyl oxygen atom, two bridging chlorine atoms, a terminal chlorine atom, a water molecule and a carboxyl oxygen atom of a neighboring molecule. The carboxyl oxygen atoms of DL-Hpipe-2 are coordinated to two cadmium atoms. The unit cell consists of two types of one-dimensional polymer structures: [CdCl2(D-Hpipe-2)(H2O)] and [CdCl2(L-Hpipe-2)(H2O)]. Therefore, it is better to write [CdCl2(DL-Hpipe-2)(H2O)] as [CdCl2(D-Hpipe-2)(H2O)][CdCl2(L-Hpipe-2)(H2O)]. The crystal structure of [CdBr2(DL-Hpipe-3)] is monoclinic with space group P2(1). The cadmium atom is in a distorted octahedral geometry ligated by two carboxyl oxygen atoms and four bridging bromine atoms. This complex consists of either D-Hpipe-3 or L-Hpipe-3. Therefore [CdBr2(DL-Hpipe-3)] is written as [CdBr2(D or L-Hpipe-3)]. The crystal of [CdCl2(Hpipe-4)] is monoclinic with space group P2(1)/n. The structure is similar to that of [CdBr2(D or L-Hpipe-3)].
已制备出六种卤化镉（II）与dl-哌啶-2-羧酸（DL-Hpipe-2）、dl-哌啶-3-羧酸（DL-Hpipe-3）和哌啶-4-羧酸（Hpipe-4）形成的配合物，并通过红外光谱、拉曼光谱和热分析对其进行了表征。通过X射线衍射测定了[CdCl2(DL-Hpipe-2)(H2O)]、[CdBr2(DL-Hpipe-3)]和[CdCl2(Hpipe-4)]这三种配合物的晶体结构。这三种配合物具有由卤原子桥联的一维聚合物结构。[CdCl2(DL-Hpipe-2)(H2O)]的晶体为正交晶系，空间群为Pca2(1)。镉原子呈八面体几何构型，由一个羧基氧原子、两个桥联氯原子、一个端基氯原子、一个水分子和相邻分子的一个羧基氧原子配位。DL-Hpipe-2的羧基氧原子与两个镉原子配位。晶胞由两种一维聚合物结构组成：[CdCl2(D-Hpipe-2)(H2O)]和[CdCl2(L-Hpipe-2)(H2O)]。因此，最好将[CdCl2(DL-Hpipe-2)(H2O)]写成[CdCl2(D-Hpipe-2)(H2O)][CdCl2(L-Hpipe-2)(H2O)]。[CdBr2(DL-Hpipe-3)]的晶体为单斜晶系，空间群为P2(1)。镉原子呈扭曲的八面体几何构型，由两个羧基氧原子和四个桥联溴原子配位。该配合物由D-Hpipe-3或L-Hpipe-3组成。因此，[CdBr2(DL-Hpipe-3)]写成[CdBr2(D或L-Hpipe-3)]。[CdCl2(Hpipe-4)]的晶体为单斜晶系，空间群为P2(1)/n。其结构与[CdBr2(D或L-Hpipe-3)]的结构相似。
