【作者】 姚蕊；

【导师】 吴本来；

【作者基本信息】 郑州大学 ， 无机化学， 2013， 硕士

【摘要】 特定配体的选择性合成和配位超分子的自组装研究,为配合物在医药领域的发展提供了依据,使配位化学在生物医药领域的研究受到比以往更多的关注。本文所涉及到的配合物,其设计的初衷是利用与生物体内DNA的组成相似的肌苷为原料,通过对它的衍生获得具有丰富配位点的氮杂环羧酸类有机配体2-(6-oxo-6H-purin-1(9H)-yl) propionic acid(H2L),再与不同的金属盐自组装特定的配合物,研究其合成过程、结构及相关性能。本文最终得到了2个稀土金属配合物和4个过渡金属配合物,即,[La(HL)3(H2O)2]n·nH2O(1)、[Ce(HL)3(H2O)2]n·4nH2O (2)、[Co(HL)2(H2O)2]n (3)、[Cd(L)H2O]n(4)、[Pb(HL)(C2O4)0.5(H2O)]n·2nH2O(5)、[Zn(L)]n(6)。其中配合物1和2结构极为相似,同为单斜晶系,P21/c空间群,一维链状结构,配体中参与配位的均为羧基氧原子,咪唑氮原子以及嘧啶环上的羰基氧原子均未参与配位。所不同的是合成方法,前者采用常温挥发法,后者采用扩散法,所含晶格水的量也不同。相同点是都通过复杂的分子间氢键及嘧啶环与咪唑环间的π-π作用堆积形成三维超分子化合物。配合物3-5均为二维结构,配合物3属正交晶系,Pcab空间群,六配位的Co(Ⅱ)处于微扭曲的八面体的反演中心,二维结构由两种大小不同的格子所构成；配合物4为单斜晶系,P21/c空间群,Cd(Ⅱ)处于五配位环境中,配体上的两个咪唑氮都参与配位,二维结构中含有两个大小不同的环;配合物5为单斜晶系,P21/c空间群,Pb(Ⅱ)处于六配位环境中,六个配位原子均为氧原子,与稀土金属配合物所不同的是,草酸根通过氧原子参与配位；配合物6为三维网状结构,单斜晶系,P21/c空间群,中心金属Zn(Ⅱ)采取四配位模式形成变形四面体构型,Zn(Ⅱ)分别与两个羧基氧原子和两个咪唑氮原子配位。在以上配合物中配体共表现出四种配位模式,配合物1、2及5中仅有羧基氧原子参与配位,其中部分羧基为螯合配位,其余为单齿配位；配合物3中的羧基氧均为单齿配位,与咪唑氮的配位形成首尾桥联作用；值得一提的是配合物4和6,相同点是配体咪唑上的两个氮原子均同时参与配位,不同的是配合物4中配体为μ3桥联,而配合物6中为μ4桥联。更为有趣的是这两个配合物展示出了较为罕见的热稳定性,推测这一性质很可能与这样的配位模式有着密切关系。对配合物1和2的吸附试验表明,配合物1和2只有表面吸附,却未能进入到网络微孔中。配合物3的磁性研究表明,该配合物具有反铁磁性。更多还原

【Abstract】 The research of coordination chemistry in biomedical field has drawn increasing attention compared with the past decades because of the selective synthesis of specific ligand and the investigation upon the self-assembly of coordination supermolecules which will provide a basis for the development of medicine. The complexes mentioned in this paper were originally designed by using raw materials whose composition is similar to that of DNA, and through a further derivation an organic ligand containing N-heterocycle and carboxylic acid groups was finally gotten. The targeted ligand,2-(6-oxo-6H-purin-1(9H)-yl) propionic acid (H2L), is a multifunctional ligand and has multiple coordination atoms. By trying to reaction with various rare earth metal salts and the transition metal salts to obtain unique complexes, and it has been further proceeded to study upon the synthesis methods, structures and the relative properties.This paper has ultimately obtained two rare earth metal complexes and four transition metal complexes, namely,[La(HL)3(H2O)2]n·H2O (1),[Ce(HL)3(H2O)2n·4nH2O (2),[Co(HL)2(H2O)2]n (3),[Cd(L)H2O]n (4),[Pb(HL)(C2O4)0.5(H2O)]n·2nH2O (5), and [Zn(L)]n (6). Complexes1and2have similar structure, and crystallize in a monoclinic space group P21/c. In the1-D chain structure, the coordination atoms all are O atoms, the Nimidazole atoms and N pyrimidyl atoms do not involve in coordination. The differences between the two are that complex1was synthesed by evaporation at normal temperatures whereas complex2was produced by a diffusion method. The3-D supramolecular structures of both compounds are formed by the complicated hydrogen bonds and π-π stacking interactions. Complexes3-5all are2-D structures. Complex3crystallizes in the orthorhombic space group Pcab. The hexacoordinated metal ions are in the center of a slightly distorted octahedron, and the2-D structure is composed by two-sized nets. Complex4belongs to monoclinic space group P21/c, the Cd(Ⅱ) centers are in a five-coordinated environment, in which the two imidazole nitrogen atoms of ligand involved in the coordination. The2-D structure of4contains two different rings. Complex5also crystallizes in a monoclinic space group P21/c, and the metal nodes Pb(II) are in a eight-coordinated environment ligated by eight oxygen atoms from carboxyls of L and oxalate ligand. Complex6is a3-D network structure, and crystallizes in a monoclinic system P21/c space group. The central metal Zn(II) adopts a four-coordinated mode and locates in a distorted tetrahedral environment coordinated with two carboxyl oxygen atoms and two imidazole nitrogen atoms, respectively.Ligand H2L displays four coordination modes in the above complexes. In1,2and5, only carboxyl oxygen atoms participate in the coordination, with partial carboxyls in a chelating mode and the others in a monodentate mode. All carboxyl groups in L in complex3only adopt monodentate coordination in combination with the coordination of imidazole nitrogen to make L act as bridge ligand. It’s worth saying that two Nimidazoie atoms are participated in the coordination. In complexes4and6, H2L ligands adopt the μ3and μ4bridge mode, respectively. As to say the properties, the two complexes exhibit a relatively rare thermal stability, which may relate to their coordination modes.The N2adsorption experiments show that complexes1and2only have surface adsorption and failed to get to the microporosity of networks. The magnetic studies of complex3show that complex3has antiferromagnetism.更多还原