Structural Diversity in the Solid-State Structures of the Rubidium and Cesium Salts of 2,6-Dimesitylphenylphosphane

A coordination environment reminiscent of a paddle-wheel is exhibited by aryl groups about one of the two cesium ions in CsP(H)Dmp (Dmp=2,6-dimesitylphenyl; structure depicted on the right), which has now been synthesized and is found to exhibit Cs⁺{Cs₂[P(H)Dmp]₃}⁻ contact ion pairs in the solid state. In contrast, the analogous rubidium compound displays a Rb₄P₄ cube as the central structural motif.     

Electroconduction of Potassium,Rubidium, and Cesium Orthophosphates

Russian Journal of Electrochemistry -     

Crystal Structures of Anhydrous Potassium, Rubidium, and Cesium Hypophosphites

Crystals of anhydrous K, Rb, and Cs hypophosphites have been obtained. The structures of these compounds were determined by X-ray diffraction analysis. The structure in general is a packing of layers of metal cations and hypophosphite anions coordinated to them. In all compounds, the hypophosphite anion performs the function of a bridge between four cations in a layer. Each oxygen atom is linked to two cations. The compounds RbH₂PO₂ and CsH₂PO₂ are isostructural.     

Synthesis and Crystal Structure of Rubidium Uranyltricarbonate

A procedure for the synthesis of uranyltricarbonatetetrarubidium Rb₄UO₂(CO₃)₃ was developed. Its crystal structure was determined by X-ray diffraction analysis: space group C2/c; a=10.778(5) , b=9.381(2) , c=12.509(3) . =94.42(3)°, Z=4; 1178 independent reflections, R=0.0662.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 5, 2005, pp. 387–390.Original Russian Text Copyright © 2005 by Chernorukov, Mikhailov, Knyazev, Kanishcheva, Zamkovaya.     

Application of the Study of Reactivity of Alkaline Salts of Isocyanuric Acid to the Synthesis of Mono- and Trisubstituted Isocyanurates

Reactivity of alkaline salts of isocyanuric acid has been studied. It has been established that the nucleophilic substitution is not selective because of the protonic exchanges between salts and substituted derivatives. The synthesis of mono or trisubstituted derivative is due to secondary reactions and to solvent effects. With this study, it has been possible to settle a method to prepare mono and trisubstituted derivatives of isocyanuric acid.     

Synthesis and Enzymatic Degradation of Aliphatic Polyesters Copolymerized with Trimesic Acid

Abstract

Network copolyesters were made from adipic acid and ethylene glycol with 10–40 mol% trimesic acid (Y). Prepolymers prepared by melt polycondensation were cast from dimethylformamide solution and postpolymerized at 260°C for various times to form a network. The degree of reaction (D _R), estimated from the infrared absorbance of hydroxyl and methylene groups, increased with increasing postpolymerization time and leveled out at about 90% after 4–6 hours. Heat distortion temperatures (T _h) measured by thermomechanical analysis increased greatly from ?83 to 48°C upon the incorporation of Y. Wide-angle x-ray diffraction patterns showed that the copolymer films are amorphous. Density, tensile strength, and Young's modulus decreased for the copolymers with 10–30 mol% Y, whereas they increased drastically for the copolymer with 40 mol% Y. The enzymatic degradation was estimated by the weight loss of the copolymer films in buffer solutions with a lipase at 37°C. The weight loss decreased remarkably with increasing Y and showed no weight loss for the copolymer with 40 mol% Y. On the other hand, the weight loss by alkali hydrolysis increased for the copolymers with 10 and 20 mol% Y, implying a difference in the degradation mechanism between enzymatic degradation and alkali hydrolysis.     

铷和铯含量的示波极谱滴定法测定

用了示波极谱滴定法测定硝酸盐样品中铷和铯的含量，回收率为９７７８％～１００３％，相对标准偏差均值为０２１％。该法以示波极谱图形突变来确定滴定终点，终点直观，不受溶液颜色、沉淀的影响，具有准、快、简、省的特点，有广泛的应用价值     

气相色谱法测定均三甲苯和均苯三甲酸

提出了均三甲苯及其液相氧化目标产物均苯三甲酸的色谱分析方法.通过甲醇酯化将均苯三甲酸转化为均苯三甲酸三甲酯再进行色谱分析,分别以异丙苯和苯甲酸苄酯为内标对均三甲苯和均苯三甲酸三甲酯进行气相色谱分析.结果表明:均三甲苯和均苯三甲酸三甲酯的相对标准偏差分别为0.68%,2.84%,均三甲苯和均苯三甲酸三甲酯、均苯三甲酸的回收率分别为97.72%～104.27%,98.41%～104.72%,98.38%～102.51%.     

用于肽合成的肟铯盐裂解剂的制备及性能

以获得侧链全保护的多肽为总目标,选择接入溴乙酰基把手的Wang树脂作为固相载体,采用多肽固相合成法制备了3种模型肽,将其用于对具有弱碱性和强亲核性的肟盐类裂解剂的研究;设计并制备了5种不同结构的肟铯盐,将其用于模型肽的裂解,并选择综合效果最好的2-吡啶甲醛肟铯盐进行裂解条件的优化.结果表明,肟铯盐类裂解剂可以温和、高效地裂解模型肽,得到侧链全保护的多肽.     

Synthesis and Properties of Onium Salts of Isocyanuric Acid. Crystal Structure of Tetraphenylphosphonium Isocyanurate

Previously unknown tetrabutylammonium and tetraphenylphosphonium isocyanurates were prepared, and their IR spectra were examined. The crystal structure of tetraphenylphosphonium isocyanurate was determined.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 3, 2005, pp. 417–421.Original Russian Text Copyright © 2005 by Flakina, Chekhlov, Kushch, Lyubovskaya.     

Study on Preparation and Catalytic Performance of Silica Supported Cesium Acid Salts of 12-tungstophoric Add

Supported Cesium Acid Salts of 12-tungstophric acid exhibit very high activities as catalysts for various reactions, because of their superacidity, high surface area and insolubility in water and polar solvents^[1,2]. In this work, supported Cesium acid salts are prepared by first impregnating the aqueous solution of Cesium Carbonate onto SiO₂, followed by drying and calcining, then impregnating the aqueous solution of H₃PW₁₂O₄₀, followed by drying and calcining. The etherification of Light FCC Gasoline with methanol was conducted in a Fixed-bed reactor. Products were analyzed by GC.     

Synthesis,Structure, and One-electron Redox Reactions of Novel Benzodithiolium Salts

Abstract

Novel stable benzodithiolium salts have been synthesized and characterized by X-ray crystallographic analysis, which have been readily converted to the first isolable dithiolyl radicals by one-electron reduction.     

二氧化硅负载磷钼钒酸铯选择性催化硝化苯酚为邻硝基苯酚

采用溶胶-凝胶法制备了二氧化硅负载磷钼钒酸铯催化剂,利用XRD、红外、SEM以及物理吸附等技术手段对催化剂进行了表征分析,并以稀硝酸（30%）为硝化剂,考察了该催化剂对苯酚硝化反应的催化性能,系统研究了反应时间、催化剂用量、硝酸与苯酚用量以及催化剂重复利用等对催化反应的影响。 结果表明,制备的负载磷钼钒酸铯催化剂具有典型的Keggin结构,在温和的苯酚硝化反应条件下,表现出优良的催化活性和高的邻硝基苯酚选择性,在实验优化条件下,邻硝基苯酚收率达到88%,催化剂回收方便可多次重复使用。 负载磷钼钒酸铯催化苯酚硝化反应结合水蒸汽蒸馏提供了一种简单可行的制备邻硝基苯酚的方法。     

N,N,N′′-三取代氨基甲酰脲类化合物的合成

N，N－二取代脲和取代三氯乙酰胺反应合成了10种未见文献报道的标题化合物，产物结构经元素分析、IR和^1H NMR确证。初步生物活性测定表明多数化合物具有明显的除草活性。     

t-BAMBP萃取-原子吸收分光光度法测定矿物中微量铷、铯

利用4-叔丁基-2-（α-甲苄基）酚（t-BAMBP）萃取矿物中微量的铷和铯,再利用原子吸收分光光度法测定其在萃取剂中的浓度．并对稀释剂的选择、萃取酸碱度、相比影响、萃取时间及干扰离子等进行了研究．实验结果表明,检出限分别为铷:0.02μg/g,铯:0.08μg/g。标准浓度在0~200μg/50mL时,线性关系大于0.9989,样品加标回收率为96.4%~104.4%之间,相对误差小于1%．     

Liquid Nickel Salts: Synthesis,Crystal Structure Determination,and Electrochemical Synthesis of Nickel Nanoparticles

New nickel‐containing ionic liquids were synthesized, characterized and their electrochemistry was investigated. In addition, a mechanism for the electrochemical synthesis of nanoparticles from these compounds is proposed. In these so‐called liquid metal salts, the nickel(II) cation is octahedrally coordinated by six N‐alkylimidazole ligands. The different counter anions that were used are bis(trifluoromethanesulfonyl)imide (Tf₂N^?), trifluoromethanesulfonate (OTf^?) and methanesulfonate (OMs^?). Several different N‐alkylimidazoles were considered, with the alkyl sidechain ranging in length from methyl to dodecyl. The newly synthesized liquid metal salts were characterized by CHN analysis, FTIR, DSC, TGA and viscosity measurements. An odd‐even effect was observed for the melting temperatures and viscosities of the ionic liquids, with the complexes with an even number of carbon atoms in the alkyl chain of the imidazole having a higher melting temperature and a lower viscosity than the complexes with an odd number of carbons. The crystal structures of several of the nickel(II) complexes that are not liquid at room temperature were determined. The electrochemistry of the compounds with the lowest viscosities was investigated. The nickel(II) cation could be reduced but surprisingly no nickel deposits were obtained on the electrode. Instead, nickel nanoparticles were formed at 100 % selectivity, as confirmed by TEM. The magnetic properties of these nanoparticles were investigated by SQUID measurements.