节点文献
4-磺基苯甲酸配合物的合成及结构研究
Syntheses and Structural Studies of 4-Sulfobenzoate Coordination Compounds
【作者】 张丽平;
【导师】 朱龙观;
【作者基本信息】 浙江大学 , 化学, 2007, 博士
【摘要】 本博士毕业论文主要研究4—磺基苯甲酸(4-sb)与中性含氮配体形成的金属配合物的合成、晶体结构和性质。使用的中性配体为2,2′-联吡啶(2,2′-bipy)、4,4′-联吡啶(4,4′-bipy)、1,10-邻菲罗啉(1,10-phen)和8—羟基喹啉(HQ),研究的金属离子为主族金属Pb以及过渡金属Cu、Zn、Cd和Mn。总共合成了17个配位化合物和一个复合物,并解析了所有化合物的结构。1.对于金属铅配合物研究了在水热合成条件下中性配体对配合物空间拓扑结构的影响,共合成六个含铅单晶、一个复合物,分别为:{[Pb(4-sb)(phen)}·(H2O)}n(1),[Pb(4-sb)(2,2′-bipy)]n(2),[Pb2(4-sb)2(H2O)2]n(3),[Pb2(4-sb)2(H2O)4]n(4),{[Pb(4-sb)(4,4′-bipy)1/2]·(4,4′-bipy)1/2}n(5),[Pb(4-sb)2(H2O)2]2-[(H2Q)2]2+·4H2O(6)和[Hbpe]22+[4-sb]2-·3H2O(7)。配合物1和2中的中性含氮配体为2,2′-bipy和1,10-phen,中心金属铅周围都有七个配位原子,扩展结构为2—D空间网络拓扑结构;配合物3和4仅含有Pb、4-sb和配位水分子,这两个配合物具有不同的空间网络结构:配合物3具有3—D空间网络结构,而配合物4则是1—D链状结构;配合物5是一个三维具有孔道的化合物,孔道被客体分子4,4′-bipy占据,配合物6则为1—D结构;六个铅的配合物中,4—磺基苯甲酸共有八种配位方式,配合物3和6中各存在两种配位方式,配合物1、2、4、5中共四种配位方式。在化合物1、2和6中铅的配位数是7,化合物4中铅的配位数是6,而化合物3中的二个铅为6和7,这几个化合物中铅的孤对电子具有立体化学活性;在配合物5中,铅的配位数为8,孤对电子基本上不具有立体化学活性。总之,对于金属铅化合物的配位情况分析与研究手段一般从以下几个方面考虑:(1)中性配体的影响(2)孤对电子的影响(3)小于范德华半径作用范围的弱键(4)铅的键价是否大约在2左右。要把以上几个方面的因素综合起来考虑,分析其配位构型,并最终确定铅化合物的配位环境及其扩展空间网络结构。2.对于过渡金属Cu、Zn、Cd和Mn与桥联配体4,4′-bipy和4-sb形成的配合物,我们研究了在不同配合物中4,4′-bipy配位方式的变化,共合成七个配位化合物,它们分别是:{[Cu(4,4′-bipy)(H2O)4](4-sb)}n(8),[Zn(4,4′-bipy)2(H2O)4](4-Hsb)2(9),{[Zn(4,4′-bipy)(H2O)4](4-sb)}n(10),[Mn(4,4′-bipy)2(H2O)4](4-Hsb)2(11),[Mn(4,4′-bipy)2(H2O)4](4-sb)(4H2O)(12),{[Mn(4-sb)(4,4′-bipy)(H2O)3](2H2O)}n(13),{[Cd2(4-sb)2(4,4′-bipy)4(H2O)3]4H2O}n(14)。在配合物8和10中,4,4′-bipy为双齿桥联配体,配合物8的空间扩展结构为一维链状;在配合物9、11—13中,4,4′-bipy都是单齿配位,这种4,4′-bipy呈现系列单齿配位的情况比较少见;在配合物14中,4,4′-bipy有三种配位方式,单齿配位,双核桥联子和一维桥联方式,这种在同一个化合物中,同时出现三种配位方式的现象也是非常少见的。我们这一章介绍的几个单齿配位的4,4′-bipy与4-sb形成的配位聚合物中,由氢键扩展形成三维网络结构。本章获得的一系列单齿配位的4,4′-bipy的配位聚合物为研究4,4′-bipy与其他体系组合,合成具有多样的拓扑结构的配位聚合物提供了很好的参考价值。3.除了前面提到的Mn(Ⅱ)/4,4′-bipy配合物外,我们进一步研究了2,2′-bipy和1,10-phen与Mn/4-sb体系的配合物。共合成了三个配合物,分别是[Mn(phen)2(H2O)2](4-sb)·6.5H2O(15),[Mn(4-Hsb)2(phen)2](16)和[Mn(4-sb)(2,2′-bipy)(H2O)3]·H2O(17)。其中,配合物15和16合成自同一体系,但分子结构完全不同。它们的合成采用的反应物是同一体系,配合物15中4-sb以游离态存在,而且羧基脱掉质子,但配合物16中4-sb参与配位、羧基质子化。它们结构的不同主要有两个方面的影响因素:一、反应的时间和温度的影响,即晶体15是动力学稳定的产物,晶体16是热力学稳定的产物;二、溶液pH值的影响,即晶体15在pH值较大(≈6)的情况下析出,而晶体16在pH值较小(≈4)的条件下析出。配合物17为单核化合物,中心金属离子7配位,在锰(Ⅱ)化合物中这种配位方式相对较少见。通过对配合物15和16的研究可以看出:在同一体系,配比相同,同样的实验方法和温度下,溶液的pH值对配合物的结构有至关重要的影响,pH值变化的原因是随着溶液中溶剂水的挥发,溶液中[H+]逐渐增大,pH值就逐渐变小。4.水热(溶剂热)条件的in situ反应目前大部分机理还不甚清楚,这是近年来广大化学工作者关注的一个焦点。我们用4-sb、4,4′-bipy与硝酸铜在水热条件下反应,获得了一种in situ单晶产物,即Cu3(SO4)(OH)4(18),这个化合物单晶制备十分困难,本文成功制备的主要原因是硫酸根在实验过程中由4-sb水解缓慢生成、这样有利于高质量晶体的形成。
【Abstract】 In this presentation, we report the syntheses, crystal structures and properties of the metal coordination complexes constructed from 4-sulfobenzoate (4-sb). In the procedures of syntheses, we chose 2,2’-bipyridine (2,2’-bipy), 4,4’-bipyridine (4,4’-bipy), 1,10-phenanthroline (1,10-phen) and 8—hydroxyquinoline (HQ) as neutral ligands, and lead, copper, zinc, cadmium and manganese as metal ions in our research. Totally, we got eighteen compounds, listed as follows:1. For lead complexes, we focused on the effect of neutral ligands on the structures. We discuss six lead(Ⅱ) complexes and one organic complex: {[b(4-sb)(phen)]·(H2O)}n (1), [Pb(4-sb)(2,2’-bipy)]n (2), [Pb2(4-sb)2(H2O)2]n(3), [Pb2(4-sb)2(H2O)4]n (4), {[Pb(4-sb)(4,4’-bipy)1/2]’(4,4’-bipy)1/2}n(5), [Pb(4-sb)2(H2O)2]2-[(H2Q)2]2+·4H2O (6) and [Hbpe]22+ [4.sb]<sup>2-·3H2O(7). Complexes 1 and 2 consist of 2-D networks in which the Pb(Ⅱ) atoms are seven-coordinated to terminal ligands and sb2-. In complexes 3 and 4, the lead(Ⅱ) atoms are surrounded by 4-sb ligands and water molecules. The molecular structure of the complex 3 is a 3-D network, while 4 is a 1-D linear chain. Complex 5 is a 3-D coordination polymer with 1-D cavities, filled with 4,4’-bipy guest molecules. In the 1-D complex 6, the neutral ligand is protonated and non-coordinating. The coordination numbers of Pb(Ⅱ) atoms are seven in complexes 1, 2 and 6, and six in complex 4, six and seven in complex 3, where the lone electron pairs are all stereo-chemical activity. However, in complex 5 the lone electron pair is stereo-chemical inactivity. In a word, we can analyse the coordination environment of Pb(Ⅱ) atoms according to the following regulations: (1) the effect of neutral ligands; (2) the impact of lone pair electron; (3) the short contacts near lead(Ⅱ) atoms; (4) the bond Value of lead.2. For transition metal (Cu, Zn, Cd, Mn) complexes constructed from 4,4’-bipy and 4-sb, we report the diverse coordination modes of 4,4’-bipy ligands. We have synthesized seven compounds: {[Cu(4,4’-bipy)(H2O)4](4-sb)}n(8), [Zn(4,4’-bipy)2(H2O)4] (4-Hsb)2(9), {[Zn(4,4’-bipy) (H2O)4] (4-sb)}n(10), [Mn(4,4’-bipy)2(H2O)4] (4-Hsb)2(11), [Mn(4,4’-bipy)2(H2O)4](4-sb)(4H2O) (12), {[Mn(4-sb)(4,4’-bipy)(H2O)3] (2H2O)}n(13), {[Cd2(4-sb)2(4,4’-bipy)4(H2O)3]4H2O}n(14).In complexes 8 and 10, the 4,4’-bipy ligands are bidentate, generating1-D chains; while the most interesting topological feature in complexes 9 and 11-13, is the monodentate function for 4,4’-bipy. It is worth noting that the 4,4’-bipy ligands exhibit three kinds of coordination modes in complex 14, which is sparse. Successful exploration in these seven complexes may provide useful information for other combination systems with 4,4’-bipy to control the coordination ability of bridging ligands and construct novel functional frameworks with specific topologies.3. We research ulterriorly the effect of terminal ligands (2,2’-bipy, 1,10-phen) on the coordination geometries of Mn-4-sb system. Three complexes are synthesized in this chapter: [Mn(phen)2(H2O)2](4-sb)·6.5H2O(15), [Mn(4-Hsb)2(phen)2] (16) and [Mn(4-sb)(2,2’-bipy)(H2O)3]·H2O(17). Complexes 15 and 16 were obtained from the same reactant system, but they have different composition and structures. In complex 15, the 4-sb ligand does not coordinate to Mn2+ ion and only acts as counteranion, while in complex 16, the 4-sb ligand coordinates to metal ion. There are two main factors govern the diverse structures of complexes 15 and 16: (1) reaction time and temperature, that is to say, complex 15 is kinetically stable complex, while complex 16 is thermally stable one. (2) pH value, complex 15 was grown from aqueous solution with higher pH (≈6), while for 16, the pH value is lower (≈4).4. Hydro(solvo)thermal in situ ligand synthesis has been rapidly developed over the past several years due to its effectiveness, simplicity and environmental friendliness. However, up to now, most of the mechanisms of the in situ ligand syntheses have not been very clear. When we put copper nitrate, 4-sb and 4,4’-bipy together under hydrothermal conditions, complex Cu3(SO4)(OH)4(18) was obtained. Furthermore, no sulfonate was used in the preparation of 18, which was the product of the hydrolysis of 4-sb. The work about in situ ligand synthesis of 4-sb has been done a little, and we will make greater efforts on it in the future.
【Key words】 metal complex; crystal structure; hydrogen bonds; π-πstacking; 4-sulfobenzoate;