气相色谱法研究配位化合物的热稳定性V.活性炭负载的铁(III)草酸配合物的热分解

本文用气相色谱法跟踪热分解气相产物,配合穆斯堡尔谱检测固相产物,研究了活性炭负载的草酸铁(Ⅲ)和三草酸合铁(Ⅲ)酸钾在H_2中的热分解过程,比较了与相应纯盐的异同。发现活性炭对负载的铁(Ⅲ)的草酸配合物的性质和热分解过程有很大的影响,使其分解起始温度低于纯盐,产物在载体表面高度分散,Fe(Ⅱ)的还原困难。研究结果表明,载体和金属离子、配体之间存在较强的相互作用,形成了区别于纯盐的载体表面配合物。     

气相色谱法研究金属草酸配合物的热分解

用气相色谱(GC)、热重(TG)和差示扫描量热(DSC)法研究金属草酸配合物的热分解已有报道。本文用GC法研究两种合成的草酸配合物[三水合三草酸合铁(Ⅲ)酸钾和三水合三草酸合钴(Ⅲ)酸钾]的热分解反应,配合TG,DSC测试数据,探讨了分解机理,并用微机编程序计算获得反应级数和活化能。     

气相色谱法研究配位化合物的热稳定性VI.含氧载体负载的铁(III)草酸配合物的热分解

本文用气相色谱法、穆斯堡尔谱和红外光谱研究了硅胶、氧化铝和氧化镁负载的草酸铁(Ⅲ)和三草酸合铁(Ⅲ)酸钾的性质及在H_2中的热分解。结果表明,含氧载体对负载型配合物的影响涉及到载体表面配合物的热稳定性、热分解机理,分解产物、金属离子的还原和产物的分散度等各个方面,而且不同载体的影响也各不相同。红外光谱研究表明,由于载体表面与配体C_2O_4~的相互作用,在氧化铝和氧化镁表面形成一些新的载体表面配合物,故其热分解性质不同于纯盐。     

三草酸合铁(Ⅲ)酸钾的室温固相合成与晶体结构表征

以草酸钾和氯化铁为原料,通过室温固固反应合成了三草酸合铁(Ⅲ)酸钾配合物,用ICP、元素分析、X-射线单晶衍射、X-射线粉末衍射、红外光谱及热分析等方法对其组成和结构进行了表征.实验结果表明:三草酸合铁(Ⅲ)酸钾K3[Fe(C2O4)3]·3H2O的晶体结构属于单斜晶系,P2(1)/n空间群,晶胞参数a=0.774 52(4) nm,b=1.990 39(10) nm,c=1.034 31(5) nm,β=107.704(2)°,Z=4,Dc=2.148 g/cm~3.草酸根中的O原子与Fe原子形成了配位数为6的变形八面体配合物,在N2气氛中的热分解过程分4步,最后的残余物为FeO和K_2CO_3.     

1,2-双烷基(芳基)硫代乙烷对金的萃取性质和配合物的研究

本文研究了1,2-双烷基(芳基)硫代乙烷(L)——1,2-双(正辛基硫代)乙烷(BOTE)、1,2-双(正戊基硫代)乙烷(BATE)、1,2-双(苯基硫代)乙烷(BPTE)对金的萃取及其配合物的性质.双烷基硫代乙烷对金具有很强的萃取能力,可定量地萃取金.在溶液中,当[L]≥[Au~(3 )]时,Au与L形成1∶1Au-L配合物,而在[L]<[Au~(3 )]时,则为2∶1Au-L配合物.固态时,Au(Ⅲ)、Au(Ⅰ)与L只形成2∶1配合物(AuCl_3)_2L和AaCl)_2L.讨论了BOTE和BATE与Au(Ⅲ)、Au(Ⅰ)配合物的IR和~1H NMR谱.IR谱证实了关于Au(Ⅰ)配合物为线型结构的推断,并借助金原子的交换机理,解释了配合物与配位体的~1H NMR谱外观相似的原因.详细分析了Au(Ⅲ)配合物低频区的IR数据,提出了配合物有离子型结构的新证据.     

单核配合物溶液配位体亲核体系分光光度数据的一般处理

本文提出单核配合物溶液配位体亲核体系分光光度数据的一般处理。本法可由已知稳定常数的配合物,测定未知配合物的稳定常数,溶液组成和摩尔吸光系数;数据处理是直线外推,可见不可见光区都适用,ε也可自由选择,接续配合物的数目不受限制,选择了βi较小βj较大(硫代硫酸锌-EDTA)和βi较大βj较小(氟化铁-草酸铁)二体系进行了试验。本文提出的方法将为分光光度法研究配合物溶液提供一个新途径。     

设计功能性多核配合物的一种重要桥基—1.2—二硫代草酸根

本文综述了１．２－二硫代草酸根（ｄｔＯ）的配位性质及其多核配合物的合成及结构特征，并讨论了ｄｔＯ配合物的光，电，磁性及应用。     

固态配合物RE(C5H8NS2)3(C12H8N2)的光谱性质

在无水乙醇中, 合成了组成为RE(C5H8NS2)3(C12H8N2) (RE=La, Pr, Nd, Sm～Lu) 的固态配合物. IR光谱表明配合物中稀土离子(RE3 )与吡咯烷二硫代氨基甲酸铵 (APDC)中的硫原子和1, 10-邻菲咯琳(o-phen) 中的氮原子均双齿配位; UV光谱显示配合物中o-phen与稀土离子之间的能量传递是主要过程, 配合物的最大吸收与o-phen相比有微小的红移; FS光谱表明配合物Sm(C5H8NS2)3(C12H8N2)和Eu(C5H8NS2)3(C12H8N2)具有很强的荧光性质.     

三草酸合铁(Ⅲ)酸钾的制备及结构组成测定

通过对三草酸合铁(Ⅲ)酸钾合成的实验条件进行优化,可在2 h内获得晶体产物。用KMnO4滴定法和磁化率测定方法,对产物结构组成进行测定,确定所合成的配合物化学式为K3[Fe(C2O4)3]·3H2O,有关测定数据与理论值相吻合。     

N,N'-双(2-吡啶乙基)二硫代草酰胺根桥联的三核铜(Ⅱ)配合物的合成及性质

0引言多原子桥联配体的多核配合物中,顺磁离子间磁偶合作用的研究对阐明磁性和结构的关系以及设计新型分子基磁性材料具有重要的理论意义。草酸根及草酰胺根桥联的多核配合物得到了较为广泛和深入的研究[1~5]。硫原子取代两个氧原子后,形成二硫代草酸根及二硫代草酰胺根,由于硫     

有机配合剂稳定高价稀土元素的研究 I.丙二酸水溶液中稳定Pr(IV)的研究

本文通过751G型发光光度计和pHS-2型酸度计, 研究了有机配合剂(Pr(IV)-CH~2(COO)~2^-^2)碱式碳酸盐溶于丙二酸水溶 液中, Pr(IV)在该溶液中的行为和稳定情况。总Pr量用EDTA配位滴定法, 二甲酸橙作指示剂;Pr(IV)分析用碘量法, 并扣除空白。     

Antipyrilquinoneimine dye formation by coupling aniline derivatives with 4-aminoantipyrine in the presence of ruthenium nanoparticles

The coupling of 4-aminoantipyrine (4-AAP) with aniline derivatives catalyzed by ruthenium nanoparticles (Rnp) has been studied by UV-Vis spectroscopy in aqueous medium. The rate constant for antipyrilquinoneimine dye formation depends on the nature of the aniline substituent and the pH, ionic strength and temperature of the reaction medium. The maximum rate constant of the dye formation reaction is observed at pH 3.6. Aniline derivatives with electron donating substituents show higher rate constant values than those with electron withdrawing substituents, with increasing rate constant values in the order: N,N-dimethyl aniline > o-toluidine > o-chloroaniline > m-chloroaniline. With pseudo first order kinetics, the total order is 1.0 + 1.0 + 1.0 = 3.0, which includes the orders with respect to amine, 4-AAP and Rnp. Studies on these effects help to complete the kinetic analysis as well as propose the reaction pathway. Furthermore, TEM measurement confirms that the nanoscalar size of the Rnp is 7 nm.     

A Novel Green Synthesis of Silver Nanoparticles Using Gum Karaya: Characterization,Antimicrobial and Catalytic Activity Studies

Stable silver nanoparticles have been synthesized using gum karaya acting as both reducing and stabilizing agent without using any synthetic reagent. The reaction is performed using water, which is an environmentally safe solvent. This reaction was carried out in an autoclave at a pressure of 15 psi and 120 °C temperature by varying the time. The influence of different parameters such as time, change of concentration of silver nitrate and concentration of gum karaya on the formation of silver nanoparticles has been studied. The synthesized silver nanoparticles are characterized by UV–Vis spectroscopy, FTIR, XRD and TEM. UV–Vis analysis of the sample confirmed the formation of silver nanoparticles exhibiting a sharp peak at a wavelength of 420 nm. TEM micrographs showed the formation of well-dispersed silver nanoparticles of size 2–4 nm. The antimicrobial activity of silver nanoparticles stabilized in gum karaya is tested against Escherichia coli, Micrococcus luteus and is found to be possessing inhibiting property. The silver nanoparticles stabilized in gum karaya exhibited very good catalytic activity and the kinetics of the reaction was found to be pseudo first order with respect to the 4-nitrophenol.     

二过碘酸合镍(IV)氧化酒石酸钠的动力学

1 引言近年来,关于超常价态过渡金属氧化还原反应动力学的研究逐渐增多。四价镍的各种配合物氧化有机物和低价金属离子的动力学及机理在文献中也有报导.但对Ni(Ⅳ)和高碘酸根的配合物(DPN)氧化有机物的动力学研究尚处于起步阶段.本文采用停止流动分光光度法对DPN在碱性介质中的动力学机理进行了研究。提出了一个包括两组相互平行的两步单电子转移连串反应的反应机理。据此导出了能够解释本文全部实验事实的速率方程,并求得了表观活化参数。     

新不对称偶氮羧衍生物的合成及其与钙离子的β型显色反应

我们合成了五种新的不对称偶氮羧衍生物,并研究了它们与钙离子之间的一种特殊反应-β型反应,考察了试剂分子结构与反应性能的关系。着重探讨了对羧基偶氮羧与钙离子的β型反应行为,在柠檬酸介质中,钙离子与该试剂形成组成比为1:2的灵敏的稳定配合物,最大吸收波长为718nm(Δλ=157nm),表观摩尔吸光系数ε=1.51×10^5L.mol^-^1.cm^-^1,测定条件下,1-13μgCa/25mL符合Beer定律,采用小体积显色,反应可在15分钟内进行完全,配合物可稳定4小时不变。动力学研究结果表明,对羧基偶氮羧与钙离子只发生β型反应,反应级数为2。     

偶氮染料吸附和光催化氧化动力学

以甲基橙和酸性大红两种偶氮染料为模拟污染有机物,对它们的暗吸附和光催化氧化行为进行研究.实验结果表明,两种偶氮染料的吸附受溶液酸碱度影响很大,酸性（pH=3）条件下,两种染料吸附量都很大,酸性大红吸附量更大；近中性（pH≈6）时两种染料的吸附显著减少；碱性（pH=9）条件下两种染料不发生吸附.光催化反应结果显示,碱性条件或酸性条件下两种染料降解速度都很快.说明在不同酸碱度条件下,光催化反应按不同机理进行.酸性条件下,反应在催化剂表面进行,在碱性介质中,光催化氧化在溶液中进行.提出了一个碱性条件下的动力学方程,经过进一步简化,可以得到表观一级方程,形式上和准一级L-H方程十分相似,但其含义不同.     

Kinetics and mechanism of naringenin reaction with Ce(IV) in different aqueous solutions of dimethylsulfoxide

The reaction of naringenin with Ce(IV) was studied in different aqueous solutions of DMSO (50–80% v/v) and various sulfuric acid concentrations using a spectrophotometric method. The reaction was arranged to be under pseudo‐first‐order condition with respect to Ce(IV). It was found that 1 mol of Ce(IV)sulfate on average has consumed by about 2 mol of naringenin to complete the reaction. To determine the stoichiometric ratios of metal ion and the ligand in the formed complex species, the continuous variation method has been used. The results showed that pseudo‐first‐order rate constants increase with increasing naringenin concentration and decrease by increasing the amount of DMSO and sulfuric acid in solution. The rate constant (k₁) was measured at different conditions. Finally, a mechanism consistent with the observed results has been proposed and discussed at various aqueous DMSO solutions. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 715–724, 2011     

Kinetic study of the complex reaction between copper(II) and 2-(2′-hydroxy-3′-methoxyphenyl)benzothiazole

2-(2′-Hydroxy-3′-methoxyphenyl)benzothiazole reacts with copper(II) in an ethanol/water mixture to form an O,S chelate which exhibits the remarkable property of changing the chelation site above a pH of ca. 5.0, to the O,N site. The detailed kinetics of this reaction in an ethanol/water mixture (3:1) at a temperature of 25 °C was investigated using a stopped-flow spectrophotometric technique employing a wavelength of 400 nm. The initial complex, Cu(O,S), is formed via a fast, reversible second-order complex formation step whereupon the formation of the Cu (O,N) follows first order kinetics. The Cu(O,N) complex is, however, unstable towards internal electron exchange and after the reaction is complete, a black polymeric material very slowly precipitates out of solution. Rate and equilibrium constants for the postulated reactions are presented and discussed.     

CeO2 nanorods and gold nanocrystals supported on CeO2 nanorods as catalyst

The formation mechanism of uniform CeO2 structure at the nanometer scale via a wet-chemical reaction is of great interest in fundamental study as well as a variety of applications. In this work, large-scale well-crystallized CeO2 nanorods with uniform diameters in the range of 20-30 nm and lengths up to tens of micrometers are first synthesized through a hydrothermal synthetic route in 5 M KOH solution at 180 degrees C for 45 h without any templates and surfactants. The nanorod formation involves dehydration of CeO2 nanoparticles and orientation growth along the 110 direction in KOH solution. Subsequently, gold nanoparticles with crystallite sizes between 10 and 20 nm are loaded on the surface of CeO2 nanorods using HAuCl4 solution as the gold source and NaBH4 solution as a reducing agent. The synthesized Au/CeO2 nanorods demonstrate a higher catalytic activity in CO oxidation than the pure CeO2 nanorods.     

碱性介质中二过碲酸合铜(III)氧化乙二醇的反应动力学及机理

本文采用分光光度法研究了碱性介质中二过碲酸合铜(III)(DTC)氧化乙二醇(Glgcol)在291.2-303.2K的反应动力学机理。结果表明, 反应对氧化剂(DTC)是一级, 对乙二醇也是一级, 准一级([Glycol]0>>[DTC]0)速率常数Kobs随着[OH^-]增加而增加, 随着[TeO4^2^-]增加而降低, 并且有负盐效应, 提出了一种含有前期平衡的反应机理。据此导出了一个能够解释全部实验事实的速率方程, 求出平衡常数、速控步骤的速率常数及298.2K时的活化参数。