两种铯的水杨酸化合物的合成与表征

一直以来,水杨酸(2-羟基苯甲酸)及其衍生物被认为具有抗肿瘤活性,将水杨酸及其衍生物制成各种金属化合物,它们的活性会大大增强。通常人们对碱金属Na 、K 研究的比较多,原因是它们在生物体中大量存在。近年来,人们对稀碱金属Rb 、Cs 日益感兴趣,主要在于Rb 、Cs 的生物必需性及     

Synthesis of mesocyclic and macrocyclic polythioethers using the cesium dithiolate technique

The mesocyclic trithioethers, 1,4,7-trithiacyclodecane, 1,4,7-trithiacycloundecane, 1,4,8-trithiacycloundecane, and 1,5,9-trithiacyclododecane; the mesocyclic trithioether ketones, 1,4,7-trithiacyclodecan-9-one; 1,4,8-trithiacycloundecan-6-one, and 1,5,9-trithiacyclododecan-3-one; and the mesocyclic trithioether alcohols, 1,4,7-trithiacyclodecan-9-ol, 1,4,8-trithiacycloundecan-6-ol, and 1,5,9-trithiacyclododecan-3-ol, have been synthesized using the cesium dithiolate technique. In some cases, the corresponding macrocyclic hexathioether was isolated from the reaction mixture in addition to the mesocyclic trithioether; 1,4,7,11,14,17-hexathiacycloeicosane, 1,4,7,11,14,17-hexathiacycloeicosan-9,19-dione, 1,4,7,12,15,18-hexathiacyclodocosane, and 1,5,9,13,17,21-hexathiacyclotetracosane. Single-crystal X-ray structures have been determined for 1,5,9-trithiacyclododecan-3-ol and 1,4,7,12,15,18-hexathiacyclodocosane. For 1,5,9-trithiacyclododecane-3-ol, the compound crystallizes in the monoclinic space group, C2/c, with a = 10.5926( 9 ) Å, b = 15.582(2) Å, c = 13.6015(8) Å, β = 98.186(6)⁰, Z = 8, and R = 0.038. The macrocycle, 1,4,7,12,15,18-hexathiacyclodocosane, crystallizes in the orthorhombic space group, Pbca, with a = 21.406(5) Å, b = 9.810(2) Å, c = 10.225(2) Å, Z = 4, and R = 0.020.     

Synthesis of novel calixcrown derivatives with selective complexation towards cesium ions

A series of novel calix[4]arenecrown-6 derivatives with an alkenyl loop of various sizes 5-8 were synthesized via intramolecular ring closing olefin metathesis and characterized by ~1H NMR,~(13)C NMR and ESI-HRMS.Their complexation property towards cesium ion was studied by ~1H NMR technique.Two-phase extraction of alkali metal ions using UV-vis spectroscopy revealed remarkably different extractabilities.These results indicate that the complexation capacities towards cesium ions can be tuned and controll...     

Synthesis,structure, and thermal properties of fluorinated cesium beta-diketonates

Four fluorinated cesium beta-diketonates, Cs(CF₃COCHCOCF₃) (Cs(hfac)), Cs(CF₃COCHCOCH₃) (Cs(tfac)), Cs(OH₂)((Me)₃CCOCHCOCF₃) (Cs(OH₂)(ptac)), and Cs(OH₂)(PhCOCHCOCF₃) (Cs(OH₂)(btfac)), were synthesized by interaction of the corresponding beta-diketone and Cs₂CO₃ in Et₂O. The formation of Сs(CF₃C(OH)₂CH₂C(OH)₂CF₃)(CF₃COO) or Cs(CF₃C(OH)₂CH₂COCH₃)(tfac) was shown to be dependent on the reaction conditions. The compounds were characterized by elemental analysis, single crystal X-ray diffraction, and TG/DTA analysis. All compounds have ionic structures organized into pseudo chains (in the case of Cs(hfac) and Cs(CF₃C(OH)₂CH₂COCH₃)(tfac)) or pseudo layers (in other cases). According to the TG data Cs(hfac), Cs(tfac), Cs(OH₂)(ptac,) and Cs(OH₂)(btfac) decompose in inert atmosphere within the temperature range 30–550?°C.     

Ionization energies of cesium and cesium oxide clusters

The vertical ionization potentials of 7 cesium and 86 oxidized cesium clusters were determined using the technique of photoionization mass spectrometry. The spectra were obtained using a tunablecw dye laser for clusters in a mass range 1 to 2024 amu. The vertical ionization potentials (IP) are presented as a function of size and composition. The ionization energies of cesium clusters, Cs_n, decrease with cluster size. Unusually low IP were observed for the enneamer, Cs₉, and for the cesium monoxide Cs₁₁ O. With increasing oxidation of the cesium metal clusters the IP decreases (suboxides) reaches a minimum at Cs(Cs₂O)_n and then increases (superoxides).     

Synthesis of cesium selective pyridyl azocalix[n]arenes

A series of pyridylazo calix[n]arenes (n=4, 6, 8) including the first examples of mixed hetroaryl azocalix(n)arenes have been synthesized by coupling calix[n]arenes with diazonium salts derived from amino pyridines. It has been observed that the coupling reaction of diazonium salt obtained from 3-aminopyridine with calix[n]arene gives tetrakis-, hexakis- and octakis (pyridylazo)calix[n]arenes (n=4,6,8) while those derived from 4-aminopyridine give partially substituted (4-pyridylazo)calix[n]arene analogs. There is no reaction of calix(n)arenes with diazonium salts derived from 2-aminopyridine under identical conditions of experiments. The conformational analysis of synthesized compounds have been ascertained by detailed spectral measurements and single crystal X-ray analysis of 5-(3′-pyridylazo)-25,26,27,28-tetrahydroxycalix[4]arene. A rational explanation for the observed partial and exhaustive coupling reaction in the synthesis of heteroaryl azocalix(n)arenes has been suggested. Preliminary evaluation of synthesized derivatives as molecular receptors for metal ions indicates that they have good potential to function as selective ionic filters for cesium ions.     

Equilibrium and kinetic studies of the sorption of cesium by potassium nickel hexacyanoferrate complex

In the framework of Actinex program, C.E.A. launched studies for the recovery of long lived nuclides from spent fuel dissolution acidic solutions in order to destroy them by transmutation or to encapsulate them in specific matrixes. Efforts were focused on⁹⁹Tc and¹³⁵Cs which are among the most harmful elements because of their long half live (2.1·10⁵ and 2.3·10⁶ years, respectively) and mobility. The aim of this work is to examine the possible coextraction of the pertechnetate with cesium by calix[4]arenes bis-crown-6 and then to separate if from cesium by using a second calixarene.     

Synthesis of polyfunctional indoles and related heterocycles mediated by cesium and potassium bases

A general preparation of 2-substituted indoles starting from functionalized 2-alkynylanilines has been developed. This base mediated reaction has also been used to synthesize the heterocyclic core of the marine alkaloid hinckdentine A. Furthermore the reaction was successfully adapted to the solid phase. Benzofurans and isoindolones could also be prepared with this method.     

Crystal structures of cesium hydrogen oxalate and cesium oxalate dihydrate

All-Union Scientific-Research Institute for Chemical Reagents and Highly Pure Chemical Substances. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 4, pp. 154–157, July–August, 1990.     

Synthesis and characterization of hollandite-type material intended for the specific containment of radioactive cesium

The hollandite Ba₁Cs_0.28Fe_0.82Al_1.46Ti_5.72O₁₆, which has been proposed for the cesium-specific conditioning, can be synthesized either by an alcoxyde or a dry route. In both cases, a two-step protocol is applied, i.e., a calcination at 1000 °C followed by a sintering at 1200 °C. After sintering, both synthetic processes lead to a tetragonal form. According to the X-ray diffraction (XRD) patterns collected at the barium and the cesium K absorption edges, the different positions of these two elements have been evidenced with a more centered position in the oxygen cubic site of the tunnel for Ba than for Cs. On the contrary, after calcination, the two synthetic routes yield different products. The alcoxyde route gives rise to a mixture of the aforementioned Cs- and Ba-containing tetragonal I4/m hollandite, a Cs-only-containing monoclinic I2/m hollandite and an unidentified phase with a weak coherence length containing only Ba. The dry route yields a single tetragonal hollandite material containing Ba and Cs slightly different in composition from the targeted compound.     

Extraction of cesium and strontium into nitrobenzene in the presence of arsenic acid—catechol complex

Quantitative analysis of traces of Pd in a Cu matrix using X-ray fluorescence induced by protons in the MeV range is explained. The method is used for necroanalysis of small portions (20 μg) of a sample in which local inhomogeneity of Pd concentration is found. The sensitivity of the technique may reach 5 ppm (quantitative) for one hour of bombardment of metallic samples. This sensitivity of 5 ppm of Pd in 20 μg of material corresponds to 10^?11 g of Pd effectively detected. The method is rapid (15 min for the determination of 100 ppm of Pd in a Cu matrix with an accuracy of 5%), non-destructive and does not produce any residual activity. Comparative results obtained by other macrotechniques are given.     

Synthesis of novel calix[4]crown telomers and selective extraction of cesium ions

p-tert-Butylcalix[4]diazacrown-4 telomer, which contains hard and soft ion binding sites, was synthesized. It exhibited high selectivity toward cesium ions. The binding sites may complex alkali metal ions selectively.     

Synthesis of a hafnocene disilene complex

Reaction of the magnesium transmetalation product of a 1,2-dipotassiodisilane with hafnocene dichloride gives a disilene hafnocene complex. X-ray crystallography of the respective trimethylphosphane adduct provides structural proof for this assignment.     

Preparation of cesium trimolybdate by the thermal decomposition of a new oxomolybdenum(VI) oxalato complex

A new molybdenum(VI) complex Cs₂(NH₄)2[Mo₃O₈(C₂O₄)₃] (CAMO) has been prepared and characterized by chemical analysis and IR spectral studies. Thermal decomposition studies have been made using TG, DTA and DTG techniques. The compound is anhydrous and stable up to 160°C. Thereafter it decomposes in three stages. The first and the second stages occur in the temperature ranges 160–220°C and 220–280°C to give the intermediate compounds having the tentative compositions Cs₄(NH₄)₂[Mo₆O₁₆(C₂O₄)₃(CO₃)₂] and Cs₄[Mo₆O₁₆(C₂O₄)₂(CO₃)₂] respectively, the later then decomposing to give the end product Cs₂Mo₃O₁₀ at 370°C. The end product was characterized by chemical analysis, IR spectral and X-ray studies.