首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 250 毫秒
1.
合成了邻羟基苄基氨乙酸与Cu(II)的双核配合物, 并得以了单晶; 同时合成了Cu(II)、Co(II)、Ni(II)与该配体的质子化配合物, 测定了它们的组成、溶解度和摩尔电导, 研究了它们的磁性、热谱、红外光谱及电子光谱. 用四圆衍射仪测定了单晶的结构. 讨论了这些配合物的配位情况以及结构与性能的关系.  相似文献   

2.
张锋  刘祁涛 《化学学报》1993,51(3):251-256
本文用pH电位法研究了在70%(v/v)乙醇-水溶液中Cd(II)与维生素D3(VD3)和乙二胺(en)或2,2'-联吡啶(bipy)在37±0.1℃和离子强度为0.10(KNO3)条件下, 三元混配配合物的稳定性。结果表明, 上述混合配位体系均形成稳定的1:1:1型混配配合物, 且△logK值均为较大的正值(分别为+1.06和+1.54), 但相应的logX值却并不很大(分别为2.18和2.83)。从统计效应和配合物分子内的配体间疏水相互作用, 讨论了造成这种反应常结果的可能原因, 并针对如何判断三元混配配合物相对稳定性高低等问题提出了作者的见解。  相似文献   

3.
本文用pH电位法研究了在70%(v/v)乙醇-水溶液中Cd(II)与维生素D3(VD3)和乙二胺(en)或2,2'-联吡啶(bipy)在37±0.1℃和离子强度为0.10(KNO3)条件下, 三元混配配合物的稳定性。结果表明, 上述混合配位体系均形成稳定的1:1:1型混配配合物, 且△logK值均为较大的正值(分别为+1.06和+1.54), 但相应的logX值却并不很大(分别为2.18和2.83)。从统计效应和配合物分子内的配体间疏水相互作用, 讨论了造成这种反应常结果的可能原因, 并针对如何判断三元混配配合物相对稳定性高低等问题提出了作者的见解。  相似文献   

4.
本文合成了1,1'-二(N-水杨酰腙乙基)二茂铁及其过渡金属配合物,ML.nH~2O[M=Mn(II)、Co(II)、Ni(II)、Cu(II)、Zn(II)和Cd(II)],并用元素分析、UV、IR、^1HNMR、TG-DTA和摩尔电导进行了表征.配体以烯醇式以通过亚胺基氮原子和酰胺基氧负离子与金属离子配位,按摩尔比1:1结合.Ni(II)配合物有一分子DMF配位.大部分配合物比配体热稳定性高.  相似文献   

5.
本文报道用PH滴定法测得KNO3水溶液中邻苯二酚-3,6-二甲撑亚氨基二乙酸(CBMIDA, H6L)的六级酸解离常数及CBMIDA的镁(II)、钙(II)、锶(II)、钡(II)、镍(II)、锌(II)、钴(II)、镉(II)、锰(II)、铜(II)、铁(II)、钍(IV)和铀酰离子的配合物稳定常数及配合物的质子化常数. 讨论了CBMIDA的逐级酸离解的动态平衡机理以及金属离子与CBMIDA形成的各种配合物的配位形式.  相似文献   

6.
使用改进的RD-1型热导式量热计测量了镍(II), 锌(II),钴(II)-N-(间甲苯基)亚氨基二乙酸-氮三乙酸三元配合物的生成焓, 发现其大小按金属离子来说符合Irving-William序列。利用配体的多环水化结构等讨论了该三元配合物的生成焓和相应的二元配合物的生成焓, 同时求得了上述三元体系的热力学参数, 指出上述三元体系的生成熵是导致这些三元体系具有较大稳定性的根本原因。  相似文献   

7.
使用改进的RD-1型热导式量热计测量了镍(II), 锌(II),钴(II)-N-(间甲苯基)亚氨基二乙酸-氮三乙酸三元配合物的生成焓, 发现其大小按金属离子来说符合Irving-William序列。利用配体的多环水化结构等讨论了该三元配合物的生成焓和相应的二元配合物的生成焓, 同时求得了上述三元体系的热力学参数, 指出上述三元体系的生成熵是导致这些三元体系具有较大稳定性的根本原因。  相似文献   

8.
应用断流分光光度计(Stopped-Flow Spectrophotometer)研究了镍(II)与N-(对位取代苯基)氨基乙酸-(ρ-RC6H4NHCH2COOH, R=CH3O, CH3, H, Cl, 简写为NROH或HL)在25℃及30%(v/v)乙醇溶液中生成配合物的反应动力学. 实验结果表明, 不仅氨基酸配体的负离子(NRO^-或L^-)具有较高的反应活性, 而且两性离子(HN^+RO^-或^+HL^-)也是有效的反应配体. 反应按双途径进行, 即按Eigen-Tamm机理进行的NRO^-途径和以质子迁移为速率控制步骤的两性离子途径. 两性离子的反应活性(以log kHL^±表示)与配体的碱性强度(pK2)之间呈现直线自由能关系. 并发现镍(II)配合物的离解反应速率常数(log k-L^-)与配体的碱性强度(pK2)和配合物的稳定常数(log KNiL^N^i)之间均存在直线自由能关系.  相似文献   

9.
徐息良  黄仲贤 《化学学报》1986,44(10):1005-1010
本文报道了L-苏氨酸同Cu(II),Zn(II),Fe(II),Mn(II),Ca(II),Mg(II),Ni(II),Cd(II)的二元及三元配合物的pH电位法研究.电位滴定数据是使用MINIQUAD和ESTA计算机程序处理的.在每个体系中确定了最佳配合物粒子模型,并测定了在生理条件下(温度为37±0.1℃离子强度为150mmol.dm^-3NaCl)的稳定常数.结果表明在铜配合物中Cu,Thr.His混配配合物是与Cu(His)~2^-同样重要的配合物,因此需要重新计算在血浆中铜在这些配合物中的分布.虽然苏氨酸可以看作为三齿配位体,但本工作的结果并无证据支持羟基参与配位,然而在Cd-The-His体系中,Cd.Thr.His同它的1:2母体二元配合物相比表现了显著的稳定性,这可能显示了不同的配位状况.但这一点有待于进一步证实.  相似文献   

10.
冯云龙  刘世雄 《化学学报》2002,60(5):947-949
合成了两个异亚硝基乙酰丙酮亚胺Pd(II)配合物,Pd(o-BrC_6H_4-IAI)_2 (1) 和Pd(C_6H_5CH_2-IAI)_2 (2)(IAI = isonitrosoacetylacetoneimino),用IR和 Raman光谱对两个配合物进行了表征,并测定了配合物1的晶体结构。配合物1晶体 属单斜晶系,空间群为P2_1/c,晶胞参数:a = 0.8013(2) nm,b = 1.8775(4) nm,c = 0.7905(2) nm,β = 98.22(3)°,V = 1.1770(5) nm~3,Z = 2,D_c = 1.892 g·cm~(-3),F(000) = 656,R = 0.0663。在这两个配合物中,二齿 Schiff碱配体的异亚硝基(肟基)的N原子和亚胺的N原子与Pd(II)配位,形成反式 的PdN_4平面正方形配位构型。  相似文献   

11.
陈荣悌  林华宽 《化学学报》1983,41(2):103-109
The stepwise formation constants of complex compounds formed from N-(m-substituted-phenyl) glycines (m-RC6H4NHCH2COOH(m-RPhG), R = H, CH3, CH3O, Cl, NO2) with Cu(II) and Ni(II) were determined by pH method at 15, 25 35`C in 30% (V/V) ethanol solution in the presence of 0.1m NaClO4. Their thermodynamical parameters were calculated. It was found that the N-(m-substituted-phenyl) glycine complexes also showed linear free energy relationships between the stability of complex compounds and the base strength of the ligands just as the para-substituted isomers reported previously. Linear relationships not only existed between their thermodynamical parameters and the base strength of the ligands but also existed between the formation enthalpy of complex compounds and the neutralization enthalpy of the ligands and between the formation entropy of complex compounds and neutralization entropy of the ligands as well.  相似文献   

12.

The formation constants of binary and ternary complexes involved in the systems methioninehydroxamic acid (MX), glycylglycine (GG) and Cu(II) or Ni(II) were determined by pH-metric titration in aqueous solution at an ionic strength (I)= 0.15 M NaCl) and T = 25°C. Ternary species of the type (MX : GG : Ni(II) or Cu(II) : H) = (1 : 1 : 1 : r), (2 : 1 : 1 : r) and (1 : 2 : 1 : r) exist in the pH range ~3 to ~10. Differential pulse polarography (DPP) was used to follow complex formation and to study the reduction properties of these metal ions in the presence of MX, and GG. The metal oxidation states were more stabilized in the ternary systems than in the binary systems except for a few Ni(II) systems. Spectral studies in the UV-Vis-nIR were used to monitor the presence of ternary species in the Ni(II) and Cu(II) systems. In addition, EPR studies were also used to record the magnetic properties of the binary and ternary species in the Cu(II) systems.  相似文献   

13.
Cu(Ⅱ)与α-氨基肟配体PnAO配位反应的热力学及热化学研究   总被引:1,自引:0,他引:1  
林华宽  张渊明  古宗信  陈荣悌 《化学学报》1994,52(10):1017-1021
用pH法测定了PnAO的质子化常数及Cu(Ⅱ)-PnAO,Cu(Ⅱ)-5-R-Phen-PnAO配合物的稳定常数.用直接量热法测定了PnAO的质子化热及Cu(Ⅱ)二元,三元配合物的生成热.Cu(Ⅱ)三元配合物体系与5-R-Phen的质子化体系之间存在线性热力学函数关系.并对取代基效应作了解释  相似文献   

14.
采用pH法, 在25.0±0.1℃, I=0.1 mol.dm^-^3 (KNO3)条件下, 测定了13-取代苄基-1, 4, 8, 11-四氮杂环十四烷-12,14-二酮的质子化常数及其与Cu(II)配位的平衡常数。讨论了配体与金属离子的配位方式。在25.0±0.1℃, 离子强度为0.1mol.dm^-^3 (KNO3)下, 采用分光光度法, 研究了这些配体铜(II)配合物的酸分解动力学行为。探讨了配合物酸分解机理,得到了速控步的速率常数。发现配位反应平衡常数与配体的质子化常数及配合物酸分解反应速率常数之间存在较好的Hammett型和Bronsted型直线自由能关系。同时探讨了取代基对配合物生成及酸分解的影响情况。  相似文献   

15.
The reaction of 2-mercaptonicotinic-copper (II) complex (Cu2+-MENA, 1 3n 1) with thiosalicylic acid (TSA) has been investigated spectrophotometrically in ethanol-water solution (50%, v/v) at I=O.IM (NaClO4) and 25°C. Under the acidic conditions encountered in this study, there are competing equilibria between protonation of the Cu2+-MENA binary chelate, the formation of the Cu(MENA)(TSA) ternary complex and protonation of the second ligand (TSA). The equilibrium constants for the complexation reactions and the stability of the mixed-ligand complex are determined. The optimum conditions for the predominance of the ternary complex are established and the enhancement of this complex over binary complex formation is evaluated. Complex-forming equilibria have also been examined by potentiometric-pH titrations and the experimental data are discussed in relation to various equilibria existing in solution. Structural and bonding features of the mixed-ligand complex are illustrated from considerations of the IR spectral data.  相似文献   

16.
The formation constants of ternary mixed ligand complex compounds (logK_(MAB~(MA)) formed from 1,10-phenanthroline or 2,2'-bipyridyl (A), N-(meta-substituted phenyl) glycines, (B, m-RphG, R=CH_3, H, CH_3O, Cl) with Nickel(Ⅱ), Cobalt(Ⅱ) and Zinc(Ⅱ) were determined by pH method at 25 ℃ in 30% (Volume) ethanol solution in presence of 0.1 mol·dm~(-3) NaClO_4 or 0.1 mol·dm~(-3) KNO_3. It was found that linear free energy relationships exist between the stability of ternary complex compounds and the base strengths of ligands in all six ternary systems investigated. The stability of the ternary complex compounds was discused in terms of ΔlogK_M values and HSAB theory. It was found that linear relationships also exist between ΔlogK_M and pK_2 in the Ni(II)-phen-m-RPhG ternary system.  相似文献   

17.
《Polyhedron》1986,5(7):1253-1257
Complex formation between Ni(II), Co(II) and Mn(II) and 3-(2-furyl)-2-mercaptopropenoic and 3-(2-furyl)-2-mercaptopropanoic acids has been studied using glass electrode potentiometry. Ligand-metal ion mixtures in 10% (v/v) ethanol-water containing 0.1 mol dm–3KNO3 were titrated with potassium hydroxide. The e.m.f. data obtained have been analyzed using the linearization method, and initial estimates of protonation constants for the ligands and complex formation constants have been refined with the MINIQUAD program.  相似文献   

18.
陈荣悌  林华宽 《化学学报》1988,46(8):808-811
报道了铜(II)-乙酰甘氨酸-α-氨基酸三元配合物体系的直线自由能关系. 以研究竞争性三元混配型配合物稳定性. 为认识生物体内所进行的生化反应的实质、用pH法测定了铜(II)-乙酰甘氨酸-α-氨基酸的竞争三元配合物的络合物生成常数.此处应用的α-氨基酸为L-脯氨酸, D,L-α-氨基异丁酸, L-异亮氨酸, L-缬氨酸,甘氨酸、L-丝氨酸、L-苏氨酸, 结果发现, 三元混配合物的稳定性与α-氨基酸的碱性强度间以及与原来的二元络合物间存在有线性自由能关系.  相似文献   

19.
The interaction of zinc(II), lead(II), and cadmium(II) with Glutathione (S‐L‐glutamyl‐Lcysteinylglycine) as primary ligand and zwitterionic buffers (N‐[2‐Hydroxyethyl]piperazine‐N′‐[2‐ethanesulfonic acid]) (HEPES) and (N‐Hydroxyethyl]piperazine‐N′‐[2‐hydroxy‐propanesulfonic acid]) (HEPPSO) as secondary ligands were studied by potentiometric‐pH titration in 1:1:1 ratio at 25.0 °C and I = 0.1 mol.dm?3 (KNO3). The formation constants of different normal and protonated binary and ternary complex species were calculated. Formation constants for the monohydroxy, and dihydroxy complexes for the binary systems M(II) + HEPES and M(II) + HEPPSO have been evaluated. The distribution curves for the various complex species as a function of pH were constructed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号