新型酰胺金属配合物的热力学稳定性研究

酰胺在自然界中广泛存在,生物体内很多金属酶中的酰胺都参与了金属配位,文献表明,配位的金属离子可以促进酰胺的去质子化,去质子后的酰胺氮原子是一种良好的电子授体,当前对酰胺配体的研究已有报道,为模拟抗癌药物博莱霉素,Rowland等合成了一个新型五齿酰胺配体：N,N-双(2-吡啶甲基)胺-N-乙基-2-吡啶-2-甲酰胺(L),并对其三价铁配合物的单晶结构进行了表征,实验证明此配体在配合物中的配位环境和化学性质与博莱霉素非常相似。     

吡啶-2, 6-二[N-(1′-咪唑基丙基)甲酰胺]及其锌(Ⅱ)、镉(Ⅱ)配合物的合成与光谱学研究

以吡啶-2,6-二甲酸为起始原料,经酯化后与N-(3-氨基丙基)咪唑反应合成了有机配体分子吡啶-2,6-二[N-(1'-咪唑基丙基)甲酰胺](L)及其锌(Ⅱ)、镉(Ⅱ)配合物。配体L的结构经1H NMR、13C NMR、IR、UV和元素分析表征,并采用单晶X-射线衍射方法确定了L的晶体结构,L属于正交晶系,Pbcn空间群,晶胞参数a=25.03(2),b=8.933(7),c=20.101(16),α=β=γ=90°,V=4495(6)3,Z=8,Dc=1.287g·cm-3,μ=0.095mm-1,F(000)=1856。通过元素分析确定锌(Ⅱ)、镉(Ⅱ)配合物的组成分别为(C19H23N7O2)2Zn2(ClO4)2·(CH3O)2·2H2O和(C19H23N7O2)2Cd2(ClO4)·(CH3O)3·2H2O,并采用对比分析的方法讨论了配位前后游离配体L和两种配合物的红外吸收光谱和紫外吸收光谱的谱学性质。     

2,6-双[N-(5′-羟基-3′-氮杂戊基)甲酰胺]吡啶及钴(Ⅲ)配合物的合成与光谱性质

合成了一种吡啶-2,6-双酰胺配体2,6-双[N-(5′-羟基-3′-氮杂戊基)甲酰胺]吡啶及其钴(Ⅲ)配合物,利用元素分析、核磁共振谱、红外吸收光谱和紫外-可见吸收光谱对目标产物进行结构表征与确认,经元素分析确定配合物组成为C30H46N10010Co2·4H2O·4CH3COONa,通过对比分析的方法讨论了配位前后...     

吡啶-2,6-二[N-(1′-咪唑基丙基)甲酰胺]稀土配合物的合成及其离子识别性能

将配体吡啶-2,6-二[N-(1′-咪唑基丙基)甲酰胺](L)与苦味酸稀土盐[RE(pic)-3]在甲醇中反应合成了9种吡啶-2,6-二[N-(1′-咪唑基丙基)甲酰胺\]稀土配合物,其结构经元素分析、红外光谱及紫外光谱表征,确定了配合物的结构为REL(pic)₃·nCH₃OH·H₂O(RE=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Er; n=1或2; pic为苦味酸根)。并采用紫外光谱研究了游离配体对金属离子的识别性能。结果显示：加入稀土金属离子后,L中216 nm处吸收峰消失,202 nm处吸收峰明显增强且红移至213～218 nm处,表明配体对稀土金属离子具有明显的识别能力。     

配位化学中的直线自由能关系──XX.铜(Ⅱ)-1,4,7,10-四氮杂环十三烧-11,13-二酮-α-氨基酸(5-取代邻菲罗啉)三元配合物的稳定性研究

本文采用pH法,在25.0±0.1℃,I=0.1mol·dm^-3KNO₃存在条件下,测定了铜(Ⅱ)-1,4,7,10-四氮杂环十三烷-11,13-二酮-α-氨基酸(5-取代邻菲罗啉)三元配合物的稳定常数,探讨了大环多胺配体与金属离子的配位能力、配位方式、及其在水溶液中铜(Ⅱ)配合物的稳定性,同时也研究了5-取代邻菲罗啉与铜(Ⅱ)之间的d-p反馈π键、取代基的Hammett诱导效应对三元配合物稳定性的影响。     

双[2-(2’-苯氧基)苯并噁唑]二吡啶合锰(Ⅱ)配合物的研究

X射线晶体结构分析结果表明,标题化合物晶体(C_(36)H_(26)MnN_4O_4)属单斜晶系,空间群为P2_1/a,a=0.9833(3),b=1.8646(3),c=0.9449(1)nm,Z=2,最终因子R_W=0.057利用热重分析对配合物晶体两步热分解过程进行了非等温热力学研究,探讨了反应的可能机理,得到其相应的动力学参数.第一步非等温动力学方程为:da/dt=A·exp(-E/RT)·2(1-a)~(1/2),第二步:da/dt=A·exp(-E/RT)·3/2(1-a)[-1n(1-a)]~(1/3).     

N,N''''-双(4-甲基-2-苯并噻唑基)-2,6-吡啶二酰胺钴(Ⅱ) 配合物的合成和晶体结构

0IntroductionCobaltcomplexeswithnonmacrocyclicchelatingligandscontainingtheamidefunctionalityhavere鄄ceivedmuchattentioninpastyears[1~3].Somestudieshaverevealedthatdeprotonatednitrogensoforganicamides,beinganionicinnature,arecapableofstabi鄄lizingthetriva…     

稀土—丝氨酸配合物的热力学研究

在25℃和μ=0.15mol[NaCl]条件下,用电位法测定了L-丝氨酸的质子化常数、15个稀土元素与该配体生成配合物的稳定常数,表明稀土与L-丝氨酸可生成1:1及1:2配合物。讨论了“四分组效应”及钇的位置。用量热滴定法直接测定了稀土与L-丝氨酸生成1:1配合物的△H_(101)值,计算了△S_(101)和△G_(101)值。     

桥基取代的四氮杂大环配合物热力学稳定性的研究

用电位pH法测得了5,5,7,12,12,14-六甲基-1,4,8,11-四氮杂环十四烷与Co~(2+),Ni~(2+),Cu~(2+),Zn~(2+)生成配合物的稳定常数。探讨了它们在水溶液中的可能结构,并对大环碳上甲基取代的取代数与稳定常数间的关系作了研究.发现它们在水溶液中结构为五配位的四方锥体。大环碳原子上的氢被烷基取代后,配合物稳定性下降,下降的主要原因是空间效应并非电子效应之故.     

稀土-蛋氨酸配合物的热力学

在25 ℃和μ=0.15 mol·L~(-1)[NaCl]条件下, 用pH电位法测定了L-蛋氨酸的质子化常数、15个稀土元素与该配体生成配合物的稳定常数。表明稀土与L-蛋氨酸可生成1:1配合物。讨论了“四分组效应”及钇的位置。用量热滴定法直接测定了稀土与L-蛋氨酸生成1:1配合物的△H_(101)值, 计算了△S_(101)和△G_(101)值。     

Metal ion catalysis in the beta-elimination reactions of N-[2-(4-pyridyl)ethyl]quinuclidinium and N-[2-(2-pyridyl)ethyl]quinuclidinium in aqueous solution

Catalysis of the beta-elimination reaction of N-[2-(4-pyridyl)ethyl]quinuclidinium (1) and N-[2-(2-pyridyl)ethyl]quinuclidinium (2) by Zn(2+) and Cd(2+) in OH(-)/H(2)O (pH = 5.20-6.35, 50 degrees C, and mu = 1 M KCl) has been studied. In the presence of Zn(2+), the elimination reactions of both isomers occur from the Zn(2+)-complexed substrates (C). The equilibrium constants for the dissociation of the Zn(2+)-complexes are as follows: K(d) = 0.012 +/- 0.003 M (isomer 1) and K(d) = 0.065 +/- 0.020 M (isomer 2). The value of k(C)(H2O) for isomer 1 is 4.81 x 10(-6) s(-1). For isomer 2 both the rate constants for the "water" and OH(-)-induced reaction of the Zn(2+)-complexed substrate could be measured, despite the low concentration of OH(-) in the investigated reaction mixture [k(C)H2O)= 1.97 x 10(-6) s(-1) and k(C)(OH-)= 21.9 M(-1) s(-1), respectively]. The measured metal activating factor (MetAF), i.e., the reactivity ratio between the complexed and the uncomplexed substrate, is 8.1 x 10(4) for the OH(-)-induced elimination of 2. This high MetAF can be compared with the corresponding proton activating factor (Alunni, S.; Conti, A.; Palmizio Errico, R. J. Chem. Soc., Perkin Trans. 2 2000, 453), PAF = 1.5 x 10(6) and is in agreement with an E1cb irreversible mechanism (A(xh)D(E)* + D(N)) (Guthrie, R. D.; Jencks, W. P. Acc. Chem. Res. 1989, 22, 343). A value of k(C)(H2O)>or= 23 x 10(-7) s(-1) is estimated for the Cd(2+)-complexed isomer 2, while catalysis by Cd(2+) has not been observed for isomer 1.     

PuH2气态分子热力学稳定性的理论研究

用密度泛函B3LYP方法计算了PuH2分子的微观性质、不同温度下气态PuH2分子的能量（E）、熵（S）及气态PuH2分子生成反应的标准焓变ΔH、标准熵变ΔS和标准自由能变ΔG.计算结果表明，气态PuH2分子不具有热力学稳定性.     

Spectroscopic and Electrochemical Studies of Some Molybdenum and Ruthenium Complexes of N-[(2-pyridyl)methyl]-2,2′-dipyridylamine

Interaction of the tripodal ligand N-[(2-pyridyl)methyl]-2,2′-dipyridylamine (pmdpa) with [Mo(CO)₆] under reduced pressure gave two complexes [Mo(CO)₄(pmdpa)] and [Mo(CO)₂(pmdpa)₂], depending on the mole ratio and reaction time. The i.r. spectra of the two complexes gave patterns in the metal carbonyl region confirming the proposed structures. Reaction of [Ru₃(CO)₁₂] with pmdpa in benzene gave the mononuclear complex [Ru(CO)₃(pmdpa)]. The electronic absorption spectra of the complexes exhibited visible transitions due to metal-to-ligand charge transfers. Electrochemical investigation of the complexes showed some irreversible and quasi-reversible redox reactions due tautomeric interconversions through electron transfer.     

碳酸盐热力学性质和键效应关系的研究

应用CASP标度法考察离子电荷、半径和电子构型等化学键结构因素对碳酸盐热力学性质的影响,建立了一种定量计算碳酸盐标准生成自由能△G_f⁰的新方法,计算结果与文献值相符。     

Investigation on corrosion inhibition effect of N-[4-(1,3-benzo[d]thiazol-2-ylcarbamoyl)phenyl]quinoline-6-carboxamide as a novel organic inhibitor on mild steel in 1N HCl at different temperatures: Experimental and theoretical study

A new novel organic corrosion inhibitor N-[4-(1,3-benzo[d]thiazol-2-ylcarbamoyl)phenyl]quinoline-6-carboxamide (NBCPQC) has been synthesized. The synthesized novel organic inhibitor NBCPQC used to be carried out on mild steel corrosion in 1N HCl for the first time. The studied inhibitor was once evaluated as corrosion inhibitor for mild steel in 1N of HCl solution using electrochemical research which advocated that a protective film is form by the process of inhibitor absorption on the surface of mild steel. Inhibitor shows a better inhibiton efficiency of maximum above 90% in 1N HCl medium. Inhibitors show a better efficiency by way of reducing and sluggish down the corrosion process however on growing the temperature it is weakened on controlling corrosion. In addition to this adsorption isothermal models had been interpreted to fit the adsorption behaviour of the inhibitor compound on mild steel surface. Thus the result reveals that the compound shows a Langmuir adsorption isotherm.     

The Crystal Structure of Bis[N-(2,6-diisopropylphenyl)imino] Acenaphthene and Studies of its Copper(I) and Copper(II) Complexes

The crystal structure of the rigid bidentate nitrogen ligand bis[N-(2,6-diisopropylphenyl)imino]acenaphtene (o, o'-iPr₂C₆H₃-BIAN) is described. Syntheses, electronic spectra and electrochemical properties of two copper complexes containing (o,o'-iPr₂C₆H₃-BIAN), namely, [CuCl(o,o'-iPr₂C₆H₃-BIAN)₂]Cl (1) and [Cu(o,o'-iPr₂C₆H₃-BIAN)₂](CIO₄)(AcOH)₂ (2), where AcOH=acetic acid, are reported. Although in both complexes two o,o'-iPr₂C₆H₃-BIAN ligands are coordinated, geometries about the copper atom are significantly different. While complex 2 displays a strongly "flattened" distortion towards square-planar geometry, in complex 1 square-pyramidal coordination with an almost perfect planar arrangement of two o,o'-iPr₂C₆H₃-BIAN ligands around the copper centre is suggested.     

稀土钬丙氨酸配合物的热力学性质

合成了稀土氯化钬丙氨酸配合物，[Ho2(Ala)4(H2O)8]Cl6，的晶体.用绝热量热法测定了其在78～363 K温区的热容.在214～255 K温区发现一固－固相变，相变峰温、相变焓和相变熵分别为235.09 K，3.017 kJ•mol－1和12.83 J•K－1•mol－1.用最小二乘法将实验热容值拟合成热容随温度变化的多项式方程,利用此方程式和热力学函数关系,计算出以298.15 K为参考温度的热力学函数值.在40～800 ℃温区，用热重分析和差示扫描量热法研究了该配合物的热稳定性，观察到[Ho2(Ala)4(H2O)8]Cl6分两步分解，第一步从80 ℃开始，179 ℃结束；第二步从242 ℃开始，479 ℃结束.从热分析结果推测出该配合物可能的热分解机理.