七甲茚基稀土络合物和碱金属盐的化学反应

本文用核磁共振等方法研究了稀土络合物和碱金属盐中的七甲茚基的质子化或氘化反应、亲核取代反应及络合物中稀土离子的还原反应。七甲茚基络合物比相应的茂基或茚基化合物更易与盐进行上述反应。三氘代七甲茚基在氘化反应中显示了同位素效应。     

双烃基硫桥六羰基二铁化合物亲核取代反应动力学研究

本文用分光光度法和核磁共振法研究了三种双烃基硫桥六羰基二铁—(μ,μ—SCH_2S)Fe_2(CO)_6, (μ—phCH_2S)(μ—RS)Fe_2(CO)_6(R=Me, Et)—与一系列膦配体在三种有机溶剂中进行亲核取代反应的动力学。提出了反应机理, 讨论了配体的电子因素、空间因素以及溶剂效应对取代反应速率和机理的影响。     

KINETICS STUDIES OF MINERAL-WATER REACTIONS IN HYDROTHERMAL FLOW SYSTEMS AT ELEVATED TEMPERATURES AND PRESSURES

This paper describes new experimental results on mlneral-water reaction kinetics obtained in plug-flow systems at high temperatures and pressures. As an example, the rates of reaction between calcite, fluorite, albite and water in the continuous flowing system have been measured in three separate studies. All experiments are carried out by suspending a sample bag in the plug-flow vessel, by pumping water at carefully controlled rates through the vessel, and by collecting and analyzing the reacted solution. In addition, the reaction mechanisms of fluorite and albite in a packed bed reactor have been studied with the aid of an axial dispersion model. The main factors controlling the effective dissolution rate with respect to temperature, solvent flow rate, and chemistry of the input solutions have been evaluated. It is also found that a non-steady state process is, in some cases, still observed, even under conditions where steady state conditions should have been attained. These results provide informatio     

STERIC EFFECTS IN REACTIONS OF METAL COMPLEXES. THE LIGAND SUBSTITUTION PROCESSES

Abstract

A model for the calculation of the activation energy for the ligand substitution processes in the metal complexes, occuring in the polar solvents, is suggested. The model takes into account sharp repulsion between the ligands at small distances. The structure of the transition state is analysed depending on the sharp repulsion distance between the ligands, symmetry factor α, and position of the incoming group with respect to the outgoing group (cis or trans). It is shown that for certain values of the parameters cis-substitution may be preferable than trans-substitution.     

胺固化端环氧基二硅氧烷动力学及性能研究

合成了１，３－二甲基－１，３－二乙基－１，３－双［３－（２，３－环氧丙氧基）丙基］二硅氧烷（ＴＥＤＳ）．对其与二正丁胺的模型反应、与ＤＤＭ（４，４’－二氨基二苯基甲烷）的固化反应劝力学研究表明，反应对ＴＥＤＳ为一级反应．ＴＥＤＳ改性环氧Ｅ—５１体系的动态力学性能、冲击性能和形态结构的研究表明，随改性体系中ＴＥＤＳ含量的增加，体系的玻璃化温度是线性下降、冲击强度增大、冲击试样的断裂面渐渐显现出韧性断裂的特征．     

金属复合催化剂对煤气化的暂态动力学研究

采用阶跃扰动技术进行了金属复合催化剂对煤气化的暂态动力学研究。根据实验结果推导得出了该反应过程是催化剂表面富氧活性部位先与煤焦反应生成一个CO分子，然后此CO分子从催化剂表面脱附，接着催化剂吸附气态的CO2生成一个CO并且夺得一个氧原子实现自身还原的过程，在此基础上建立了煤的催化气化的物料平衡方程组，对各步骤的反应速率常数进行了求解，在本文采用的实验条件下，各反应步骤的反应速率常数分别为0.0703 mol·g-1·min-1·kPa-1;0.0959 mol·g-1·min-1·kPa-1;0.00539 mol·g-1·min-1·kPa-1; 0.0321mol·g-1·min-1·kPa-1。由此得出了该反应历程的控制步骤为CO2的吸附步骤等历程信息。     

过渡金属五卤苯基化合物的研究 Ⅸ. 双(二苯基甲基膦)合(五氯苯基)氯化镍(Ⅱ)与吡啶及取代吡啶亲核取代反应动力学和机理

前文报道了配合物trans-(Ph_2PR)_2Ni(C_8Cl_5)X(R=Me、Et、n-Pr;X=Cl、Br、I)与无机离子的亲核取代反应动力学和机理研究。反应遵循两项速率定律k_(obs)=k_1+k_2[Y],共中k_1、k_2分别为溶剂途径和试剂途径速率常数,[Y]为试剂浓度。然而,与吡啶或取代吡啶(am)进行反应时,表观速率常数     

OCTAHEDRAL METAL CARBONYLS. XXVIII.1 KINETICS AND MECHANISM OF OXIDATIVE ELIMINATION REACTIONS OF SUBSTITUTED GROUP VI-B METAL CARBONYLS WITH TIN- AND GERMANIUM-CONTAINING OXIDIZING AGENTS

Abstract

The kinetics and mechanism of reactions of (2,2′-dipyridyl)W(CO)₄ with SnCl₄, (C₆H₅)SnCl₃, (n-C₄H₉)SnCl₃ and (C₆H₅)₂SnCl₂, and of (o-phenanthroline)Mo(CO)₄ with GeI₄ have been investigated employing stopped flow and conventional kinetic techniques. The oxidizing agent-dependent rate laws are encompassed in a mechanism which involves reversible addition of two successive molecules of the oxidant to the substrate, followed by other, rapid, steps. For the reaction of (C₆H₅SnCl₂ with (dipy)W(CO)₄ at 95–115°, a parallel reaction path probably involving rate-determining dissociation of CO was also observed. Rates were found to be very sensitive to the nature of the substituents bonded to the Group IV-A metal, being greatest for electron-withdrawing substituents. Different rate laws were observed for reactions which yielded products of different stereochemistries.     

对苯乙烯磺酸钠聚合动力学及与丙烯酰胺共聚合的研究

采用膨胀计法研究了对苯乙烯磺酸钠(SSS)在水溶液中聚合动力学,确定了聚合速率方程,测定了聚合表观活化能,并研究了对苯乙烯磺酸钠与丙烯酰胺(AM )在水溶液中共聚合的动力学行为,利用聚电解质———共聚物P(SSS -co -AM)与阳离子表面活性剂N ,N ,N- 三甲基十六烷基溴化铵(CTAB)的复合作用,采用电导滴定法测定了共聚物的组成,从而测得了对苯乙烯磺酸钠与丙烯酰胺的竞聚率.研究结果表明,对苯乙烯磺酸钠聚合速率方程为RP =K[M]1 .0 [I]0 .53,说明链终止为双基终止方式,引发过程与单体浓度无关;聚合表观活化能为84 . 96kJ·mol- 1 ;采用Kelen Tudos方法,求得对苯乙烯磺酸钠(SSS)和丙烯酰胺(AM)两单体的竞聚率分别为rSSS =0 . 2 7,rAM =2 . 2 1;采用Alfrey Price经验规则估算了单体苯乙烯磺酸钠的Q、e值为QSSS=0 .2 2 ,eSSS=0 .4 6 .     

程序升温焙烧技术研究水滑石热分解动力学

催化剂前体一般为硝酸盐、碳酸盐、草酸盐和水滑石等易热分解的化合物,经过干燥、高温焙烧以及还原、活化处理后,得到催化剂的活性组分。焙烧条件的选择是催化剂制备过程中的重要环节,一般采用ＴＧＤＴＡ分析来确定［１］。高温下有些载体分子内失水以及含结晶水的前体,在不同温度下水的逐步脱除会使ＴＧＤＴＡ曲线变得复杂,影响对这些化合物本身热分解动力学的计算。程序升温焙烧（ＴＰＣ）技术是一种比较简易、方便的实验方法［２］,可以灵敏、直观地研究催化剂前驱体的热分解过程并进行动力学计算。水滑石（ｈｙｄｒｏｔａｌｃ…     

苯乙烯Ziegler-Natta聚合扩散控制动力学研究

本文研究苯乙烯在TiCl_3-Al(C_2H_5)_3催化下于甲苯、正庚烷或甲苯-正庚烷混合物介质中的聚合动力学。提出了一个含催化剂球形聚合物颗粒中发生单体扩散控制聚合的模型,导出的式子统一解释了不同介质中扩散阻力造成的不同程度的速率表减,定量说明了在聚笨乙烯良溶剂中聚合时扩散阻力小于在不良溶剂中时。     

碱金属盐和碱土金属盐溶液的红外光谱研究进展

利用红外光谱技术可以直观地从分子水平上研究溶液中离子-离子和离子-分子之间的相互作用情况,本文引了44篇参考文献,对碱金属盐及碱金属盐溶液的红外光谱研究进展情况进行了综述。     

单核铁配合物与过氧酸反应的研究

本文用波谱及高压液相色谱（ＨＰＬＣ）方法研究了二氯代三－２－吡啶甲基胺的铁（Ⅲ）配合物（ＦｅＴＰＡＣｌ＿２ＣｌＯ＿４），三─６─甲基─２─吡啶甲基胺合铁（Ⅱ）与苯甲酸的配合物（Ｆｅ（Ⅱ）ＴＬＡＯＢｚＣｌＯ＿４）同单过氧化邻苯二甲酸六水合镁盐（ｍｏｎｏｐｅｒｏｘｙｐｈｔｈａｌｉｃａｃｉｄ，ｍａｇｎｅｓｉｕｍｓａｌｔｈｅｘａｈｙｄｒａｔｅ，即ＭＰＰＡ）的反应。提出了过氧键的两种断裂（即均裂和异裂）机理，分析了中心离子价态、配体结构等因素对反应机理的影响；并通过ＦｅＴＰＡＣｌ＿２ＣｌＯ＿４与间氯代过氧代苯甲酸（ｍｃＰＢＡ）的反应，研究了过氧酸结构对反应机理的影响。实验结果表明：就过氧酸中过氧键发生均裂的程度而言：三价铁配合物与过氧酸的反应＞二价铁配合物与过氧酸的反应；ＭＰＰＡ反应体系＞ＭＣＰＢＡ反应体系。     

A PROTON NMR STUDY OF THE STEREOCHEMISTRY AND KINETICS OF THE REACTIONS OF DIMETHYL SULFOXIDE WITH POTASSIUM DICLOROGLYCINATOPLATINATE(II) AND ITS METHYL DERIVATIVES

Abstract

Amino acid complexes of general formula K[Pt(NO)Cl₂], where NO denotes the metal bonded atoms of the amino acid, react completely with solvent DMSO to yield two products, cis- and trans-Pt(NO) (DMSO)Cl, where cis and trans refer to positions of DMSO relative to coordinated nitrogen. The products were identified and kinetic data were obtained from changes in the proton nmr spectra of the amino acid, when DMSO-d₆ was the solvent, or of both amino acid and coordinated DMSO, when ordinary DMSO was the solvent. For glycine and π-aminoisobutyric acid complexes, the rate of displacement of trans chloride exceeds that of cis chloride by a factor of 3. However, subsequent equilibration favors the cis isomer over the trans isomer by a factor of 10. By contrast, for the corresponding N, N-dimethyl derivatives, the rates of formation of the two isomers are more nearly the same and the equilibrium ratio does not differ from the kinetic ratio. In addition to providing a sensitive technique for evaluating small differences in kinetic trans-effects, these observations strongly suggest that the stereochemistry of Pt(NO) (DMSO)Cl for the corresponding alanine complex described by Kukushkin and Guryamava should be denoted cis, rather than the trans reported.     

SYNTHESIS,CHARACTERIZATION, AND BIOLOGICAL STUDIES OF NOVEL ISOXAZOLIDINES: 1,3-DIPOLAR CYCLOADDITION REACTIONS

ABSTRACT

1,3-Dipolar cycloaddition reaction of nitrones to olefins is of synthetic interest. In the present work, isoxazolidines have been synthesized in high yield via intermolecular cycloaddition of N-arylnitrone with monosubstituted olefins and are employed for biological evaluation.     

乙二醇与顺丁烯二酸及邻苯二甲酸酐聚酯化反应动力学的研究

<正> 聚酯化反应是逐步增级的缩聚过程。是由氢离子催化的反应,总的动力学方程为     

铈离子与乙酰苯胺及其衍生物引发丙烯酰胺聚合动力学的研究

以铈离子和酰苯胺引发体系进行丙烯酰胺的聚合,研究了不同结构酰苯胺对聚合的影响。在H_2O-CH_3CN(3∶1)介质中聚合时,乙酰对甲苯胺对聚合的促进作用最为明显,聚合速度可提高一个数量级。测定了聚合反应的表观活化能和聚合动力学方程、由聚合物的原子发射光谱,UV光谱和端基测定,提出了聚合反应机理。     

甲壳质-重金属离子配合物的红外光谱研究

制备了多种甲壳质（ＣＴＮ）与重金属廓了的配合物,研究了其在４０００￣４００ｃｍ＾－１范围内ＦＴＩＲ特征,并对其主要吸收谱带作了经验归属。研究结果表明,在ＣＴＮ的金属螯合物中,除了－ＯＨ和－ＮＨ－参与了配位外,－Ｃ＝Ｏ亦在不同程度上参与了配位。配位后的特征峰的变化主要表现在峰强度上而非峰位置。