金的离子交换与吸附化学 II: 大孔交联聚甲基丙烯酸酯MET-802对AuCl4^-的吸附及解吸动力学

研究了大孔交联聚甲基丙烯酸酯树脂(相当于Amberlite-XAD-7)吸附和解吸AuCl4^-的动力学. 结果表明, 两种过程均由液膜扩散转向粒内扩散主控. HCl浓度对吸附AuCl4^-过程影响甚微, 研究了HCl-硫脲为解吸剂时的动力学, 表明液膜扩散常数R和粒内扩散常数B对树脂半径r0的关系服从Boyd方程.     

氨基酸与离子交换树脂相互作用的研究(Ⅱ)——高浓度下离子交换树脂超当量吸附氨基酸的机理

近年来,对氨基酸离子交换平衡虽有不少研究^[1～4],但涉及超当量吸附的研究并不多见,且解释亦各有不同^[6～7].本文拟对超当量吸附机理作深入研究.     

D201×4树脂对金(III)的吸附

Sorption behavior and mechanism of D201×4 resin for Au(III) were investigated. D201×4 resin has a good adsorptivity for Au(III) in HAc-NaAc medium at pH value of 2.63. The statically saturated Au(III) sorption capacity was 689.11 mg·g^-1 resin. The Au(III) adsorbed on D201×4 resin could be eluted by 10%NH₂CSNH₂-1 mol·L^-1 HCl(1∶1) and the elution rate was 92.2%.The adsorption of Au(III) on D201×4 follows the Freundlich isotherm. The ΔH of the adsorption was 11.03 kJ·mol^-1. The sorption rate constant was 5.42×10^-5 s^-1. The activation energy was 13.26 kJ·mol^-1. The molar coordination ratio of the functional group of D201×4 to Au(III) was about 1:1. The adsorption mechanism of resin for Au(III) was suggested according to chemical analysis and IR spectraoscopy results.     

BPR树脂对Au(Ⅰ)、Ag(Ⅰ)等氰合离子的离子交换与吸附研究(Ⅰ)——吸附、解吸动力学

考察了BPR树脂在碱性条件下对金的吸附性能。研究了BPR提取Au(Ⅰ)、Ag(Ⅰ)及其它金属氰合离子的单、双组分动力学传质过程。结果表明,树脂相上氰合离子的传质速率和摩尔比与其结构类型有密切的关系,对Au(Ⅰ)等氰合离子的NH₄SCN解吸动力学作了系统的考察。     

金的离子交换与吸附化学(Ⅱ)——大孔交联聚甲基丙烯酸酯MET-802对金的吸附平衡和柱穿透

研究了盐酸溶液中AuCl_4~-在MET-802(相当于AmberliteXAD-7)树脂上的吸附平衡和柱穿透过程。测算出0.25～1.00mol/L盐酸范围内AuCl_4~-对Cl~-的选择系数,确认AuCl_4~1在柱穿透时的传质为液膜扩散主控,液膜厚度6=5.8×10~(-2)(v)~(-0.65),与AuCl_4~-的浓度及树脂粒度无关,HETP服从Snyder方程h=1.8×10~2γ_0(v)~(0.35)。     

某些Au(III)、Au(I)配离子在溶液中扩散的研究

用毛细管色谱在25℃测定了AuCl4、[Au(SO3)2]、[Au(CSN2H4)2]、[Au(CN)2]等配位体离子在HCl溶液中的扩散系数及AuCl4阴离子的扩散活化能, 并与文献中其它配阴离子的D值比较, 认为扩散离子的质量和所载电荷可能是决定配阴离子扩散系数的主要因素.     

D201×4树脂对金(Ⅲ)的吸附

大量的金是从金矿中获得,但需要很多工序。从含金的废液、废料中再生回收金也是获得金的重要来源,如:化学电镀法、电解法、硫脲法等都比较简单易行,但有各自的局限性和缺陷。20世纪70年代,     

β-环糊精交联聚合物包结双硫腙络合物树脂对Au(Ⅲ)的吸附性能

以环氧氯丙烷为交联剂合成β-环糊精聚合物树脂被双硫腙包结的产物能与Au(Ⅲ)形成稳定的吸附络合物,并以此做吸附剂,结合原予吸收光谱法考察其对水体中痕量Au(Ⅲ)的吸附性能.研究了吸附、洗脱条件及富集倍数,提出了一种富集测定痕量Au(Ⅲ)的新方法.合成树脂对Au(Ⅲ)有良好的吸附性能,常温下静态饱和吸附量为30.98 m...     

BPR树脂对Au(Ⅰ)、Ag(Ⅰ)等氰合离子的离子交换与吸附研究(Ⅱ)——内扩散系数的测定及传质过程研究

测定了不同温度下Au(Ⅰ)、Ag(Ⅰ)、Ni(Ⅱ)、Cu(Ⅰ)、Fe(Ⅲ)氰合离子在Cl、NO₃、OH型BPR树脂中的内扩散系数和扩散活化能,BPR树脂提取Au(Ⅰ)、Ag(Ⅰ)等氰合离子的机理为离子交换过程,并求得了几种氰合离子的活化熵差值(△S-△S)。     

金(Ⅲ)与杯[4]乙酯合钠(Ⅰ)超分子化合物: [Na(C60H80O12)]+[Au(SCN)4]-的合成、结构及性能

A novel super molecule [Na(C₆₀H₈₀O₁₂)]⁺[Au(SCN)₄]^- was obtained by extraction of calix[4] arene (L) for an aqueous solution containing [AuCl₄]^-, and NaCl into CH₂Cl₂. The crystal structure and properties of the title super molecule were characterized by single-crystal X-ray diffraction, IR and ¹H NMR spectra. The X-ray single crystal structure analysis shows that the crystal was Tetragonal system with space group P4/n and the unit cell parameters were as follows: a=2.880 8(18) nm, b=2.880 8(18) nm, c=2.292 4(5) nm, and final R indices [I>2σ(I)]: R₁=0.048 5, wR₂=0.106 1. CCDC: 243229.     

碳氟表面活性剂与碳氢表面活性剂混合水溶液的表面吸附和胶团形成 I: 全氟辛酸钠-溴化辛基三甲铵体系

The surface adsorption and micelle formation of the mixed aqueous solutions of sodium perfluorooctanoate (7CFNa) and n-octyltrimethylamonium bromide (C8NBr) have been investigated by studying the surface tension-concentration relations of the solutions. It has been found that (1) The surface activity of the mixed system is much higher than that of 7CFNa and C8NBr. C8NBr is a very effective synergist for 7CFNa in surface activity, and vice versa. (2) By applying Gibbs adsorption equation, the total amount of adsorption (\I\t), the individual adsorption amount of the single surfactants (\I\7CF-, \I\C8N+) and the average molecular areas of them have been calculated. The adsorption value (saturated, \I\T) increases by 54% as the molal ratio of 7CFNa-C8NBr varies from 100:1 to 1:300. (3) From the adsorption data, it appears that the structure of surface layer of the 7CFNa-C8NBr solutions is peculiar and quite different from that of the cationic-anionic hydrocarbon surfactants. Firstly, the molal ratio of the two components in the surface layer of the 1:1 mixed solution is not 1:1 (7CFNa is adsorbed perferentially). Secondly, the molecular area at the maximum adsorption is very small (22.7A2). This could be attributed to the balancing of the electrical attraction between positive and negative ions and the mutual phobicity between the fluorocarbon and hydrocarbon chains. It has been concluded that the saturated adsorption film would possibly have a double-layer structure: the upper layer consists of the oriented 7CF- with the fluorocarbon chain toward the gaseous phase and the lower layer consists of randomly oriented C8N+ with the positive ionic head attached to the negative ionic head of 7CF- -- thus the 7CF- adsorption layer would behave as a platform for the adsorption of C8N+. (4) The limiting surface tension of the mixed solutions is very low (-15mNm-1) even if the molal ratio of 7CFNa-C8NBr is small, and so is the oil-water interfacial tension. Therefore it is capable of spreading the dilute aqu     

铌(V)-酒石酸-2-(5'-溴-2'-吡啶偶氮)-5-二乙氨基苯酚三元配便物的汞电极上的吸附

本文用线性变势吸附伏安法研究了铌(V)-酒石酸-2-(5'-溴-2'-吡啶偶氮)-5-二乙氨基苯酚三元配合物在汞电极上的电吸附性质, 测定了表面浓度, 讨论了吸附浓度的表达式及其与吸附时间、金属离子浓度、配位体浓度的关系, 验证了吸附量与电极面积及还原峰电流的关系。证明了配合物在电极上的还原是一个可逆吸附的还原过程。     

邻苯二酚-3,6-二甲撑亚氨基二乙酸的酸离解平衡及其与碱土金属、锰(II)、镉(II)、锌(II)、钴(II)、镍(II)、铜(II)、铁(II)、钍(IV)及铀酰离子配合物稳定性的研究

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.     

Dinuclear Au(I), Au(II) and Au(III) Complexes with (CF2)n Chains: Insights into The Role of Aurophilic Interactions in the Au(I) Oxidation

New dinuclear Au(I), Au(II) and Au(III) complexes containing (CF₂)_n bridging chains were obtained. Metallomacrocycles [Au₂{μ-(CF₂)₄}{μ-diphosphine}] show an uncommon figure-eight structure, the helicity inversion barrier of which is influenced by aurophilic interactions and steric constraints imposed by the diphosphine. Halogenation of LAu(CF₂)₄AuL (L=PPh₃, PMe₃, (dppf)_1/2, (binap)_1/2) gave [Au(II)]₂ species, some of which display unprecedented folded structures with Au−Au bonds. Aurophilic interactions facilitate this oxidation process by preorganizing the starting [Au(I)]₂ complexes and lowering its redox potential. The obtained [Au(II)]₂ complexes undergo thermal or photochemical elimination of R₃PAuX to give Au(III) perfluorinated auracycles. Evidence of a radical mechanism for these decomposition reactions was obtained.     

不对称变色酸双偶氮衍生物与某些非稀土元素的显色反应及其应用研究 Ⅲ:偶氮氯膦-pN与铋(Ⅲ)的β型反应的研究

本文报道铋(III)与不对称变色酸双偶氮衍生物之间的一类特殊反应──β型反应, 研究了试剂分子结构与反应性能的关系, 着重探讨铋(III)与偶氮氯膦-pN的β-型反应行为, 在高氯酸介质中, 铋(III)与上述试剂形成灵敏度很高的稳定β型配合物, λmax=713nm, εmax=9.84×10^4L·mol^-^1·cm^-^1, 并考察了反应酸度、显色剂浓度、有机溶剂(或表面活性剂)、显色温度及显色时间等对反应的影响, 测定了α和β型配合物的组成, 初步探索了α和β型配合物之间相互转化的规律。     

Coordination chemistry of the cyclo-(P(5)tBu(4))(-) ion: monomeric and oligomeric copper(I), silver(I) and gold(I) complexes

[Na{cyclo-(P(5)tBu(4))}] (1) reacts with [CuCl(PCyp(3))(2)] (Cyp=cyclo-C(5)H(9)) and [CuCl(PPh(3))(3)] (1:1) to give the corresponding copper(I) complexes with a tetra-tert-butylcyclopentaphosphanide ligand, [Cu{cyclo- (P(5)tBu(4))}(PCyp(3))(2)] (2) and [Cu{cyclo-(P(5)tBu(4))}(PPh(3))(2)] (3). The CuCl adduct of 2, [Cu(2)(mu-Cl){cyclo-(P(5)tBu(4))}(PCyp(3))(2)] (4), was obtained from the reaction of 1 with [CuCl(PCyp(3))(2)] (1:2). Compounds 2 and 3 rearrange, even at -27 degrees C, to give [Cu(4){cyclo- (P(4)tBu(3))PtBu}(4)] (5), in which ring contraction of the [cyclo-(P(5)tBu(4))](-) anion has occurred. The reaction of 1 with [AgCl(PCyp(3))](4) or [AgCl(PPh(3))(2)] (1:1) leads to the formation of [Ag(4){cyclo-(P(4)tBu(3))PtBu}(4)] (6). Intermediates, which are most probably mononuclear, "[Ag{cyclo-(P(5)tBu(4))}(PR(3))(2)]" (R=Cyp, Ph) could be detected in the reaction mixtures, but not isolated. Finally, the reaction of 1 with [AuCl(PCyp(3))] (1:1) yielded [Au{cyclo-(P(5)tBu(4))}(PCyp(3))] (7), whereas an inseparable mixture of [Au(3){cyclo-(P(5)tBu(4))}(3)] (8) and [Au(4){cyclo-(P(4)tBu(3))PtBu}(4)] (9) was obtained from the analogous reaction with [AuCl(PPh(3))]. Complexes 3-7 were characterised by (31)P NMR spectroscopy, and X-ray crystal structures were determined for 3-9.     

Fluorescence study of the interaction between metal ions and methyl methacrylate–methacrylic acid copolymers in aqueous solutions: thallium(I), calcium(II), and terbium(III)

 The binding of the cations thallium(I), calcium(II) and terbium(III) to methyl methacrylate– methacrylic acid copolymers with different fractions of acid groups (x) has been studied in aqueous solution at various pH values using the fluorescence of covalently bonded 9-vinyl anthracene as a probe. In all cases, the extent of binding increases as a function of the charge of the polymer with either increasing fraction of carboxylic acids or of pH. However, differences are observed in the behavior of the three cations. With Tl(I), quenching of the anthracene group fluorescence is observed, indicating that the thallium(I) approaches the probe and suggesting that the alkylanthracene is probably in a relatively polar region. Binding constants have been determined from anthracene quenching data and from studies with the fluo-rescent-probe sodium pyrenetetra-sulfonate. Good agreement is obtained between the two methods, and values for the binding constants increase from 250 to 950 M^-1 as x increases from 0.39 to 1. It is suggested that the cation is held in the polyelectrolyte domain, partly by Debye–Hückel effects and partly by more specific interactions. Stronger binding is found with calcium(II) and terbium(III), and in this case increases in fluorescence intensity are observed on complexation due to the anthracene group being in a more hydrophobic region, probably as a result of conformational changes in the polymer chain. In the former case the stoichiometry of the interaction was determined from the fluorescence data to involve two carboxylate groups bound per calcium. Association constants were found using murexide as an indicator of free calcium to vary from 8400 to 37 000 M^-1 as x increases from 0.39 to 1. It is suggested that in this case specific calcium(II)–carboxylate interactions contribute to the binding. With terbium(III), a greater increase in the probe fluorescence intensity was observed than with calcium, and it is suggested that the interaction with the polymer is even stronger, leading to a more pronounced conformational change in the polymer. It is proposed that the terbium(III) interacts with six carboxylic groups on the polymer chain, with three being coordinated and three attracted by electrostatic interactions. Received: 10 June 1997 Accepted: 24 October 1997