甲基膦酸二(1-甲基庚基)酯萃取金(Ⅲ)的紫外光谱研究

中性含磷萃取剂萃取贵金属已有报道.Tocher等研究了磷酸三丁酯(TBP)和三辛基氧膦(TOPO)对HAuCl_4和HAuBr_4的萃取,用分配比法测定了萃合物的组成为H_3O~+·3R·yH_2O…AuX_4~-.陈景等研究了TBP和烷基氧膦(TAPO)对铂族金属萃取,发现TBP萃取HIrCl_6时,IrCl_6~(2-)萃取前后的中心离子光谱没有发生变化;萃取H_2PtCl_6时,纯TBP及萃合物红外光谱中P=O的振动频率几乎无改变.由此推断,萃取剂未与被萃离子发生配位作用,而是形成了离子缔合物2(H~+·nTBP·yH_2O)…MCl_6~(2-).可见,这类萃取剂在萃取贵金属时,首     

1-苯基-3-甲基-4-己酰基吡唑酮-5与中性磷氧供电子体对稀土元素的协同萃取

用斜率法研究了HPMCP与TOPO、TPPO、TBP三种协萃剂对三价稀土元素协同萃取的行为。探讨了氢离子浓度、萃取剂浓度与分配比的关系,确定了萃合物的组成。研究了TOPO、TBP、TPPO的协萃效应,用单浓度递变法拟定了协萃物的组成,并确定了协萃反应的形式,计算了协萃反应的平衡常数。     

N, N, N′, N′-四丁基丙二酰胺萃取Pr3+的研究

利用丙二酸二乙酯与二正丁胺反应高收率的制备了N，N，N′，N′-四丁基丙二酰胺(TBMA)萃取剂。研究了硝酸浓度、硝酸锂浓度、萃取剂浓度以及温度等对萃取Pr(Ⅲ)分配比的影响，确定了萃合物的组成，得到了不同稀释剂中萃取反应的热力学数据。结合红外光谱和摩尔电导数据初步推断了萃合物的结构。     

溶剂萃取动力学的研究III. 氯化铀酰在盐酸和磷酸三丁酯之间传质过程

本文采用上升液滴法, 研究了氯化铀酰在盐酸介质和磷酸三丁酯(TBP)之间的传质过程. 在一定浓度的盐酸溶液中, TBP 萃取铀的速率与[U] 成正比; 反萃速率与[U] 成正比, 而与[TBP] 成反比. 在温度为20~40 范围内分别测测定了萃取和反萃反应的活化能, 它们的差值与由萃取平衡分配 温度关胤系测得的焓变相符,可以认为, 萃合物UO2Cl2TBP 的生成和离解都是分步进行的中间 物是CU2Cl2TBP; 萃取速率的控制步骤是UO2Cl22TBP 的生成反应, 而反萃速率     

N，N′-二甲基-N，N′-二辛基-3-氧戊二酰胺从盐酸介质中萃取三价镧系金属的研究

以煤油/辛醇(7:3,V/V)为稀释剂,研究N,N′-二甲基-N,N′-二辛基-3-氧戊二酰胺(DMDODGA)从盐酸介质中萃取三价镧系金属的性能及反应机理;考察了水相盐酸浓度、萃取剂浓度及温度对其萃取性能的影响。结果表明分配比在所研究酸度范围内随盐酸浓度的增加先增大后减小;随萃取剂浓度的增加而增大;萃合物的组成为MCl3.2DMDODGA(M=Sm,Gd,Dy)或MCl3.DMDODGA(M=Er,Lu)。萃取过程为放热反应,升高温度不利于萃取。同时计算出了萃取反应的平衡常数及热力学函数。萃合物的红外光谱表明羰基氧、醚氧均与镧系离子配位。     

三种中性磷萃取剂萃取分离铀(Ⅵ)与钍(Ⅳ)的研究

以磺化煤油作稀释剂,比较研究了三种中性磷萃取剂甲基膦酸二甲庚酯(P350)、磷酸三异戊酯(TiAP)和磷酸三丁酯(TBP)在HNO3溶液中对U(Ⅵ)、Th(Ⅳ)及自身对HNO_3的萃取行为。分别考察了两相接触时间、酸度、萃取剂浓度和温度对U(Ⅵ)、Th(Ⅳ)萃取分配比的影响。结果表明它们萃取HNO_3均形成1∶1型萃合物。随HNO_3浓度增加,U(Ⅵ)和Th(Ⅳ)的萃取分配比先增大后减小。相同条件下,P350对U(Ⅵ)、Th(Ⅳ)的萃取能力及铀/钍分离选择性显著大于TiAP和TBP。当被萃水相存在大量Th(Ⅳ)时,Th(Ⅳ)对U(Ⅵ)的萃取有盐析作用,U(Ⅵ)的分配比增加;Th(Ⅳ)的分配比下降。斜率分析表明三种萃取剂与U(Ⅵ)和Th(Ⅳ)分别形成2∶1和3∶1型萃合物。同时,给出了表观萃取平衡常数Kex和萃取反应热力学函数ΔH、ΔS和ΔG的值。用ICP-AES分析方法,还对三种萃取剂在不同浓度的HNO_3溶液中的溶解度进行了测定。此外,还测定了三者萃取Th(Ⅳ)的极限有机相浓度(LOC)。     

溶剂萃取动力学的研究——Ⅲ.氯化铀酰在盐酸和磷酸三丁酯之间的传质过程

本文采用上升液滴法,研究了氯化铀酰在盐酸介质和磷酸三丁酯(TBP)之间的传质过程.在一定浓度的盐酸溶液中,TBP 萃取铀的速率与[U]和[TBP]_(0)~2成正比;反萃速率与[U]_(0)成正比,而与[TBP]_(0)成反比.在温度为20～40℃范围内分别测定了萃取和反萃反应的活化能,它们的差值与由萃取平衡分配比与温度关系测得的焓变相符.可以认为,萃合物 UO_2Cl_2·2TBP 的生成和离解都是分步进行的,中间产物是 UO_2Cl_2·TBP;萃取速率的控制步骤是 UO_2Cl_2·2TBP 的生成反应,而反萃速率的控制步骤是 UO_2Cl_2·TBP 的离解反应.     

磷酸三丁酯与三烷基胺类萃取剂对锌离子的协同萃取

研究了磷酸三丁酯(TBP,B)和三烷基胺萃取剂(N235,R3N,R=C8~C10)在HCl介质中对Zn2 的萃取,该混合体系对Zn2 存在明显的协同效应,协萃系数为12.34。用斜率法和恒摩尔法探讨了萃取机理,确定了萃合物的组成为(R3N)1.5.ZnCl2.B,协萃反应方程式:ZnCl2(a) 1.5R3N(o) B(o)(R3N)1.5.ZnCl2.B(0)。计算了该反应的平衡常数和热力学函数ΔH、ΔG和ΔS,证明反应为放热过程。比较了TBP-N235的混合体系萃取Zn2 和Cd2 的性能,并考察了TBP与另一种胺类萃取剂N,N′-二(1-甲庚基)乙酰胺(N503)的混合体系对Zn2 和Cd2 的萃取。结果表明:TBP-N235的混合体系对Cd2 没有明显的协同效应;TBP-N503的混合体系对Zn2 和Cd2 协同效应都不明显。计算了TBP-N235的混合体系对Zn2 和Cd2 的分离系数,证明此体系可以从富镉溶液中分离锌。     

N，N，N′，N′-四丁基丁二酰胺的合成及其萃取稀土离子Pr（Ⅲ）的研究

合成了四取代双酰胺萃取剂N,N,N',N'-四丁基丁二酰胺(TBSA),并对萃取剂的结构进行了表征.研究了其萃取Pr(Ⅲ)的性能,考察了硝酸浓度、萃取剂浓度、硝酸锂浓度以及温度等对萃取分配比的影响.萃取反应在298K时,TBSA以甲苯为稀释剂时的热力学焓变为-12.83 kJ/mol.萃合物的组成结构为Pr(NO3)3·3TBSA.     

磷酸三丁酯、4-甲基-2戊酮对铝锂溶液中锂的萃取行为

以磷酸三丁酯(TBP)作为主要萃取剂,4-甲基2-戊酮(MIBK)作为协助萃取剂,三氯化铁(FeCl₃)作为共萃剂,以铝锂溶液体系作为试验对象,全面系统的研究了萃取剂的各组成成分、水相溶液的pH值、铁锂原子比、萃取相比、萃取时间以及静置时间对铝锂溶液中锂的萃取效果的影响。通过正交试验确定了萃取反应的最佳反应参数：萃取相比为5∶2,铁锂原子比为2∶1,pH值为1.5,TBP体积分数为70%,MIBK体积分数为15%,萃取时间为10 min。在此条件下,锂的单级萃取率可达82%,锂铝单级分离因数可达51。对萃取分离过程的反应机理进行了研究,深入探索了铁锂共萃取效应,确定了反应产生的萃合物形态为LiFeCl₄·2TBP·MIBK,并探究了萃合物形成过程中的键合方式。该萃取方法经济高效,适用于铝锂溶液中锂的分离。     

堆积模型在萃取中的应用I: 水相介质协同效应

根据推积模型提出一种新的协萃体系,即:(简单阴离子)1+(简单阴离子)2+萃取剂,并以实验证实了水相混合介质的协同效应.研究了UO2/OAc,C1/TBP-二甲苯体系的协萃效应,测定了萃合物的组成以及各种影响分配比的因素.     

聚酰胺微胶囊的制备及其在处理低浓度含铬废水中的应用研究

如何处理低浓度的含铬废水一直是工业生产中亟待解决的问题之一 ,作者就这一问题进行了大量的基础研究 .首先采用界面缩聚法制备了聚酰胺微胶囊 ,将制得的微胶囊经表面处理后使其具有主动输送功能 ,具有这一特性的微胶囊可以高效、快速提取低浓度废水中的铬 .作者还讨论了微胶囊处理含铬废水的机理、提取速率 .实验证明 ,用微胶囊处理低浓度的含铬废水是行之有效的新技术     

低温晶化对B-ZSM-5和Ti-ZSM-5物化性能的影响

 以改进方法合成的B-ZSM-5分子筛为母体,采用气固相法合成了Ti-ZSM-5分子筛,并以XRD,FT-IR,UV-Vis,XRF,SEM,ICP-AES和MAS NMR等手段对B-ZSM-5和Ti-ZSM-5进行了表征,考察了Ti-ZSM-5对苯酚羟基化反应的催化性能. 结果表明,合成B-ZSM-5时的前期低温晶化有助于晶粒的减小; 以其为母体制备的Ti-ZSM-5对苯酚羟基化反应具有优异的催化性能. 在n(PhOH)/n(H2O2)=3,n(Me2CO)/n(PhOH)=2.7,m(cat)/m(PhOH)=5%,T=353 K和t=6 h的反应条件下,苯酚转化率可达20%以上.     

Aqueous nonionic copolymer-functionalized laponite clay. A thermodynamic and spectrophotometric study to characterize its behavior toward an organic material

The affinity of functionalized Laponite clay toward an organic material in the aqueous phase was explored. Functionalization was performed by using triblock copolymers based on ethylene oxide (EO) and propylene oxide (PO) units that are EO(11)PO(16)EO(11) (L35) and PO(8)EO(23)PO(8) (10R5). Phenol (PhOH) was chosen as organic compound, which represents a contaminant prototype. To this purpose, densities and enthalpies of mixing as well as PhOH UV-absorption spectra were determined. The enthalpy and the spectrophotometry revealed PhOH-Laponite interactions whereas the volume did not. It emerged that the area occupied by PhOH on the Laponite surface is equal to that computed from the partial molar volume of PhOH in water, corroborating the insensitivity of the experimental volumes to the adsorption process. The situation where both PhOH and copolymer are simultaneously present in the aqueous Laponite suspension was also investigated. It turned out that the copolymer replaces PhOH from the water/Laponite clay interface, resulting in L35 being the more efficient. Moreover, the lateral copolymer-phenol interactions enhance the anchoring of PhOH to the solid surface. The reverse copolymer exercises the most important relevant effect. The UV-absorption spectra of PhOH in the water + copolymer + Laponite mixtures provided information that is consistent with those given by the calorimetric experiments. In conclusion, the aqueous copolymer-functionalized Laponite presents surface properties very different from the bare Laponite, favoring the removal of the organic compound from the solid surface.     

Stereochemical analysis of deuterated alkyl chains by MS/MS

Vicinally deuterated sec-alkyl phenyl ethers, CH(3)(CH(2))(m)()CH(OPh)CHD(CH(2))(n)()CH(3), display significant differences in mass spectra between threo and erythro stereoisomers. MS/MS experiments, in which parent ions of a single mass are selected and their fragmentation patterns subsequently measured, show that alkene expulsion represents virtually the only decomposition pathway. Two types of MS/MS experiment are reported: mass-analyzed ion kinetic energy (MIKE) spectroscopy of metastable ions and collisionally activated decomposition (CAD) of stable ions. The expulsion of a deuterated alkene from a monodeuterated precursor yields ionized phenol, PhOH(*)()(+) (m/z 94). The expulsion of an undeuterated alkene yields PhOD(*)()(+) (m/z 95). Without exception, the ratios (PhOD(*)()(+)/PhOH(*)()(+)) from precursors in the threo series have values greater than their diastereomers in the erythro series. The ratio of ratios, r = PhOD(*)()(+)/PhOH(*)()(+) for the threo divided by PhOD(*)()(+)/PhOH(*)()(+) for the erythro, has a value of 1.2 for the 2-phenoxy-3-deuteriobutanes and larger values for all of the higher homologues up through the monodeuterated phenoxyoctanes (m + n = 4). The highest degree of stereoselectivity, r = 5.8, is measured for 3-phenoxy-4-deuteriohexane. Experiments with multiply deuterated analogues show that alkene elimination is highly regioselective, unlike the corresponding decompositions of ionized sec-alcohols or their acetates. The fact that a large fraction of ionized sec-alkyl phenyl ethers undergo stereospecific syn-elimination means that mass spectrometry has a useful capacity to distinguish one isotopically labeled diastereomer from another.     

五氯亚硝酰合铱酸根[Ir(NO)Cl5][-]在盐酸-磷酸三丁酯体系中的萃取行为

铱在萃取过程中的行为与其存在状态有关.王水溶解含铱物料有[Ir(NO)Cl_5]~-生成,亚硝酸盐配位法分离贵金属时,盐酸酸化可使[Ir(NO_2)_6]~(3-)转变为[Ir(NO)Cl_5]~-。[Jr(NO)Cl_5]~-在溶液中的变化极其复杂,它在冶金过程中必然影响到有关的分离.本文研究[Ir(NO)Cl_5]~-在盐酸-磷酸三丁酯(TBP)体系中的萃取行为,寻求最佳萃取条件.     

The phenoxy/phenol/copper cation: a minimalistic model of bonding relations in active centers of mononuclear copper enzymes

The "bare" complex [Cu(PhOH)(PhO)](+) with a phenol (PhOH) and a phenoxy (PhO) ligand bound to copper is studied both experimentally and computationally. The binding energies and structure of this complex are probed by mass spectrometry, infrared multi-photon dissociation, and DFT calculations. Further, the monoligated complexes [Cu(PhO)](+) and [Cu(PhOH)](+) are investigated for comparison. DFT calculations on the [Cu(PhOH)(PhO)](+) complex predict that a phenolate anion interacts with copper(II) preferentially through the oxygen atom, and the bonding is associated with electron transfer to the metal center resulting in location of the unpaired electron at the aromatic moiety. Neutral phenol, on the other hand, interacts with copper preferentially through the aromatic ring. The same arrangements are also found in the monoligated complexes [Cu(PhO)](+) and [Cu(PhOH)](+). The calculations further indicate that the bond strength between the copper atom and the oxygen atom of the phenoxy radical is weakened by the presence of neutral phenol from 2.6 eV in bare [Cu(PhO)](+) to 2.1 eV in [Cu(PhOH)(PhO)](+).     

二正辛基亚砜萃取钯(II)和金(III)的动力学研究

应用连续自动测定的恒界面池装置, 研究了二正辛基亚砜(DOSO)在盐酸介质中萃取钯(II)和金(III)的动力学行为。得以了各自的萃取速率方程和表观活化能。测定了DOSO的两相分配和界面吸附性能。结果表明, DOSO萃取钯(II)为界面配本取代反应控制类型, 而萃取金(III)则为扩散或混合控制类型。     

D2HEDTPA和D2EHPA萃取汞(II)的研究

The extration of Hg2+ from HNO3 solution with (D2EHPA) and bis(2-ethylhexyl dithiophosphate (D2EHDTPA) was studied. The composition of extracted complex was determine by saturation and mol. ratio methods. The bonding of the extracted species is discussed on the basis of IR and NMR data. EHMO calcns. show that the extration capacities of the 2 extractants for Hg2+ are quite different.