Ion-exchange behaviour of copper ferricyanide

A new inorganic ion exchanger, copper ferricyanide prepared by adding copper nitrate to a potassium ferricyanide solution at 80°C has been found to be stable in acids and salt solutions. It has been characterized by chemical analysis, thermogravimetry. X-ray and infrared spectroscopy. Distribution coefficients determined for various metal ions show that the exchanger has a high affinity for heavy univalent cations. The variation of K_d for a number of metal ions as a function of nitric acid concentration and ammonium nitrate has been investigated to elucidate the probable exchange mechanism and to work out conditions for elution. Binary separations of Cs from a number of other metal ions were achieved on the column of exchanger. The exchanger is useful for the separation of¹³⁷Cs.     

簇合物[WS_4Ag_3(PPh_3)_3{S_2P(OCH_2Ph)_2}]的合成、晶体结构及非线性光学性质

本文用(NH4)2WS4,Ag犤S2P(OCH2Ph)2犦和PPh3为原料合成了簇合物犤WS4Ag3(PPh3)3狖S2P(OCH2Ph)2狚犦,并得到了晶体。晶体属正交晶系,空间群为P212121,晶胞参数a=1.32370(4)nm,b=1.34427(4)nm,c=3.83246(11)nm。X-射线单晶结构测定结果表明它具有巢状分子结构,配体(PhCH2O)2PS2-(简称dtp)的两个S原子中的一个硫原子仅与一个金属原子配位,另一个硫原子则同时与两个金属原子配位。簇合物的非线性光学性质用脉宽8ns激光在532nm波长进行了研究。该化合物表现为一定的光学吸收和强的自聚焦效应,其三阶非线性吸收系数α2=1.50×10-10m·W-1,折射系数n2=2.45×10-11esu。     

Acceleration by aliphatic mercaptan in the photoexcited carbonyl-amine redox system

Low concentration of aliphatic mercaptan increase the quantum yield of photoreduction of benzophenone by 2-butylamine, nearly to the theoretical maximum value. It is proposed that the effect arises from catalysis by mercaptain of transfer of hydrogen from the amine radical cation to the ketyl radical anion in the charge-transfer of hydrogen complex.     

Determination of the herbicide diclofop in human urine

A simple and sensitive method for the gas chromatographic determination of diclofop residues in human urine is described. Recoveries of diclofop, as its methyl ester, from fortified urine were greater than 85% at 100, 50, 10 and 1 μg kg⁻¹, and were similar with and without the inclusion of a hydrolytic step in the analytical method. However, a hydrolytic step was necessary for analysis of 24-h urine samples collected from a male applicator following a single exposure to diclofop-methyl during application to wheat using a tractor-pulled sprayer. Diclofop residues determined with hydrolysis were approximately double those without hydrolysis, suggesting that a significant portion of diclofop was excreted in the conjugated form.     

Flow-injection determination of proteins based on the lowry spectrophotometric method

The flow-injection system is based on the use of Folin-Ciocalteus reagent, with 1,4-dithio-D,L-threitol to accelerate the formation of the coloured complex. The calibration graph for bovine serum albumin is linear between 0.01 and 0.1 mg ml^?1; the detection limit is 0.005 mg ml^?1 albumin and up to 0.5 mg ml^?1 can be determined. The injection frequency is 20 h^?1. The results obtained by the flow-injection method and by the manual Lowry procedure show excellent correlation. Egg lysozyme, alkaline phosphatase and β-lactoglobulin are also tested.     

Separation of proteins of nuclear ribonucleoprotein particles by high-performance liquid chromatography

High-performance liquid chromatography (h.p.l.c.) is used to fractionate the proteins of the 30–40 S nuclear ribonucleoprotein particles. The major core proteins of the particles are eluted from a SynChropak AX-300 anion-exchange column before the more acidic higher-molecular-weight minor particle proteins. Each of the three major core proteins which can be separated from the other particle proteins by preparative polyacrylamide gel electrophoresis are eluted from the SynChropak AX-300 column as one peak. Isoelectric focusing separates each of these three apparently homogeneous peaks into a series of charge isomers ranging in isoelectric pH (pI) from 5.5 to 9.0. The core proteins of the ribonucleoprotein particles have a strong affinity to each other and form aggregates. The elution of each of the charge isomers of the three major proteins in one peak and their elution from an anion exchanger before the elution of the more acidic higher-molecular-weight minor proteins of the nuclear ribonucleoprotein particles is explained by the formation of these aggregates. The separation of the total proteins of the nuclear ribonucleoprotein particles by h.p.l.c. is similar to the separation which can be obtained by preparative electrophoresis but the l.c. technique is simpler, substantially quicker, and adaptable to large-scale preparation.     

Characterisation of the complexes of VIVO,CrIII, FeIII,CoIII, NiII and CuII with phenanthrenequinone monoxime

Summary Coordination complexes of phenanthrenequinone monoxime with V^IVO, Cr^III, Fe^III, Ni^II or Cu^II have been synthesised and characterized by magnetic moment, i.r., and thermogravimetric analysis, and electronic and electron spin resonance spectral studies.     

Hydration of alumina cluster anions in the gas phase

Hydration reactions of anionic aluminum oxide clusters were measured using a quadrupole ion trap secondary ion mass spectrometer, wherein the number of Lewis acid sites were determined. The extent of hydration varied irregularly as cluster size increased and indicated that the clusters possessed condensed structures where the majority of the Al atoms were fully coordinated, with a limited number of undercoordinated sites susceptible to hydrolysis. For maximally hydrated ions, the number of OH groups per Al decreased in an exponential fashion from 4.0 in Al(1) cluster to 1.4 in the Al(9) cluster, which was greater than that expected for a highly hydroxylated surface but less than that for solution phase alumina clusters.     

Excess Volume of Mixing of 1:1 Electrolyte Solutions at 298.15 K in the Aquo-1,4-Dioxane Mixed-Solvent System

Excess volumes of mixing for six possible binary combinations of solutions of NaCl, KCl, NaBr and KBr have been determined at constant ionic strengths of 1.000 and 2.000 mol-kg^{− 1} at 298.15 K using a dilatometer in the water + 1,4-dioxane mixed-solvent system. Pitzer’s ion-interaction model has been utilized to obtain binary and triplet interaction parameters, i.e., θ^V and ψ^V. The data were also analyzed by the Friedman Model and it is suggested that interactions between solvated ions are dictated not only by coulombic interactions but also by appreciable asymmetric effects. The data are dependent on the nature of the common ion and do not support Young’s cross-square rule. The deviation from the cross-square rule is considered to arise from preferential solvation of the ions and ion clusters in the mixed-solvent system as reflected by the appreciable contribution of triplet interactions.     

Ethylation and disproportionation of ethylbenzene over substituted AFI type molecular sieves

The vapour and liquid phase ethylation of ethylbenzene was performed over AlPO₄-5 and its substituted counter parts. The results obtained for vapour phase reactions have shown a higher catalytic activity at 350 and 400 °C. The catalysts, however, exhibited a faster deactivation rate. The results obtained for liquid phase reaction have shown a higher selectivity for para-diethylbenzene (84.4%) than the vapour phase reaction (41.5%). MnAPO-5 was found to be active up to 240 h for the liquid phase reaction. para-Diethylbenzene, meta-diethylbenzene and polyalkylbenzene were the major products obtained for ethylation of ethylbenzene. When ethylbenzene passed over MnAPO-5 yielded products, such as benzaldehyde, acetophenone, styrene and 2,3-diphenylbutane. This showed a preference for oxidation rather than disproportionation followed by alkylation. Notwithstanding the better acid characteristics of ZSM-5, MnAPO-5 could be a better choice for this class of reaction essentially due to its higher para selectivity.