共查询到20条相似文献,搜索用时 15 毫秒
1.
Y. -S. Wang B. -R. Bao W. -C. Cao 《Journal of Radioanalytical and Nuclear Chemistry》1997,222(1-2):279-281
N,N,N,N-tetrabutylsuccinylamide (TBSA) was synthesized, characterised and used for the extraction of U(VI) and Th(IV) from nitric acid solutions into n-dodecane. Extraction distribution coefficients of U(VI) and Th(IV) as a function of aqueous nitric acid concentration, extractant concentration and temperature have been measured and found that n-dodecane as diluent was superior to 50% 1,2,4-trimethyl benzene (TMB) and 50% kerosene, (OK) system for extraction of U(VI) and Th(IV). The compositions of extracted species, equilibrium constants and enthalpies of extraction reactions have also been calculated. The formation of the 121 complex of uranyl(II) ion or the 141 complex of thorium(IV) ion, nitrate ion and TBSA and extracted species was further confirmed by the IR spectra of saturated extract of U(IV) and Th(IV). 相似文献
2.
Y. Sh. Wang G. X. Sun B. R. Bao 《Journal of Radioanalytical and Nuclear Chemistry》1997,224(1-2):151-153
N,N,N,N-tetrabutylmalonamide (TBMA) was synthesized and used for extraction of uranyl(II) ion from nitric acid media in toluene. The effects of nitric acid concentration, extractant concentration, temperature and salting-out agent (LiNO3) on distribution coefficients of uranyl(II) ion have been studied. The extraction of nitric acid is also studied. The main adduct of TBMA and HNO3 is HNO3. TBMA in 1.0 mol/l nitric acid solution. The 1:2:3 complex of uranyl(II) ion, nitrate ion and TBMA as extracted species is further confirmed by IR spectra of the extraction of uranyl(II) ion with TBMA, and found that the NO
3
–
in the extraction species UO2(NO3)2·3TBMA did not participate in coordination of uranyl(II) ion. The values of thermodynamic parameters have also been calculated. 相似文献
3.
Peng Ren Yuan-Zhen Yue Kun Wang Wang-Suo Wu Ze-Yi Yan 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(3):1099-1103
Tridentate ligand N,N,N′,N′-tetraoctyl-4-oxaheptanediamide(TOOHA) and other three analogous diamides have been prepared and characterized by using NMR spectra and element analysis. The extraction of UO2 2+ and Th4+ with the present extractants was investigated at 293 ± 1 K from nitric acid solutions. n-Octane was found to be the most suitable diluent in the present study compared with other diluents tested. Extraction distribution ratios (D) of U(VI) and Th(IV) have been studied as a function of aqueous concentrations of HNO3, extractant concentrations. The results indicated that U(VI) is mainly extracted as UO2(NO3)2·2TOOHA. In the case of Th4+ ion, the possible compositions of extracted species in organic phase were presumed to be Th(NO3)4·2TOOHA and Th(NO3)4·3TOOHA. In addition, the influence of concentration of sodium nitrate as salting-out agent on the distribution ratio of U(VI) and Th(IV) with TOOHA was also evaluated. 相似文献
4.
The i.r. spectra of diiminosuccinonitrile and N,N′-dichlorodiiminosuccinonitrile were recorded as Nujol mulls, as pellets in KBr and polyethylene matrices and as solutions in CH3CN in the region 4000-30 cm−1. Raman spectra of the pure solids were obtained and polarization data were recorded from saturated solutions in CH3CN.The mutual exclusion of i.r. and Raman lines revealed that both compounds existed in the trans conformation and no additional conformers (gauche or cis) were detected in solution.The fundamental frequencies for both molecules were assigned on basis of i.r. and Raman activities, Raman polarization data and the results of normal coordinate analyses. 相似文献
5.
Peizhuo Hu Lijuan Qian Yuxin He Hailong Wang Wangsuo Wu 《Journal of Radioanalytical and Nuclear Chemistry》2013,297(1):133-137
Synthesis and characterization of N,N′-di-p-tolylpyridine-2,6-dicarboxamide (DTPDA) was carried out and used for extraction of U(VI) and Th(IV) from nitric acid solutions. The processes of extraction were determined by the slope analysis and by analyzing a function that allows the simultaneous treatment of all the experimental points obtained in different conditions. The different factors affecting the extraction distribution ratio(D) of U(VI) and Th(IV) (extraction concentration, concentrations of nitric acid, salting-out agent NaNO3 concentration, equilibration time and temperature) were investigated. The results obtained indicated that the extraction species of U(VI) and Th(IV) are mainly extracted as UO2(NO3)2·1.5DTPDA and Th(NO3)4·1.5DTPDA. The related thermodynamic functions were calculated. Back-extraction of U(VI) and Th(IV) from organic phases was also studied. 相似文献
6.
The step dissociation constants of ethylenediamine-N,N′-diacetic-N,N′-dipropionic and ethylenediamine-N,N,N′,N′-tetrapropionic acids at 298.15 K and ionic strengths of 0.1, 0.5, and 1.0 (KNO3) were determined potentiometrically. The results were extrapolated to zero ionic strength by the equation with one individual parameter. The thermodynamic constants of dissociation were calculated. The results are compared with the corresponding data on related compounds. 相似文献
7.
S. G. Il’yasov A. A. Lobanova I. Yu. Bagryanskaya T. V. Rybalova Yu. V. Gatilov 《Journal of Structural Chemistry》2009,50(6):1066-1070
The properties and behavior of dinitrourea and its potassium and dipotassium salts in different solvents have been studied
by IR and UV spectroscopy. In different media, dinitrourea can exist in several tautomeric forms. An XRD study of the potassium
and dipotassium salts of dinitrourea revealed a tendency toward equalization of the bond lengths of the C-N−-NO2 fragments compared with those of C-NH-NO2, which agrees with the results of quantum-chemical calculations. 相似文献
8.
Peizhuo Hu Lijuan Qian Xu Zhou Dengfang Pan Wangsuo Wu 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(2):1209-1213
Synthesis and characterization of N,N,N′,N′-tetraoctylsuccinylamide (TOSA) was carried out and used for extraction of U(VI) from nitric acid solutions. The effect of different factors affecting the extraction distribution ratio (TOSA concentration, concentrations of nitric acid, salting-out agent LiNO3 concentration, equilibration time, temperature and effect of diluents) have been investigated. The results obtained indicated that TOSA have a great capability to extract uranyl with kerosene-1,3,5-trimethylbenzene than other diluents, it have a high extraction distribution ratios when the concentration of TOSA is lower and not found the third matter. It was found that the main extracted species is UO2(NO3)2·TOSA. The apparent equilibrium constant of extraction determined is (2.32 ± 0.31) L3/mol3 at (298 ± 1) K. The enthalpy of extraction is ?35.20 ± 0.352 kJ/mol. 相似文献
9.
V. A. Nadtochenko V. V. Gritsenko O. A. D'yachenko G. V. Shilov A. P. Moravskii 《Russian Chemical Bulletin》1996,45(5):1224-1225
The complex of fullerene C60 withN,N,N,N-tetramethyl-p-phenylenediamine (TMPD) was synthesized and studied by X-ray analysis.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1285–1287, May, 1996. 1996 相似文献
10.
A selective and sensitive spectrophotometric method for the determination of Th(IV) has been based on the reaction with thorin and subsequent extraction of the red-orange coloured complex with N-hydroxy-N,N'-diphenylbenzamidine (HDPBA) in benzene as floated complex at pH 2.2. The complex in ethanol exhibits a maximum absorbance at 495 nm, with a molar absorptivity of 6.0x10(4) l mol(-1) cm(-1), with a Sandell's sensitivity of 3.9x10(-3) microg cm(-2). The method follows Beer's law up to 3.0 microg Th(IV) ml(-1). None of the common cations and anions tested interfere. The detection limit of the method is 0.04 microg Th(IV) ml(-1), the RSD (n=10) is 1.4%. The method has been successfully employed for the determination of thorium in various standard and monazite samples. 相似文献
11.
H. Narita T. Yaita K. Tamura S. Tachimori 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(2):381-384
The extraction of trivalent lanthanide (Ln(III) ions with two diamides: (1) N,N′-dimethyl-N,N′-diphenyl-malonamide (MA) and
(2) N,N′-dimethyl-N,N′-diphenyl-diglycolamide (DGA) from nitric acid solution was studied. Chemical bond properties of extracted
complexes were investigated by UV-VIS and FT-IR spectroscopies. The chemical bond strength between Ln(III) ions and the ligands
in extracted complexes was closely related with the magnitude of the distribution ratios of Ln(III) ions: the extracted complex
having a stronger bond between Ln(III) ion and the ligand showed a higher magnitude of the distribution ratio of Ln(III) ion. 相似文献
12.
Averin A. D. Uglov A. N. Zubrienko G. A. Abel A. S. Buryak A. K. Beletskaya I. P. 《Russian Chemical Bulletin》2021,70(11):2164-2179
Russian Chemical Bulletin - The Pd-catalyzed tetraarylation of diamines and oxadiamines with 2,7-dibromonaphthalenes and 4,4′-dibromobiphenyl was studied. These reactions gave the... 相似文献
13.
Summary
N,N,N,N-Tetramethylisophthalthioamide (Hmpt) was cyclopalladated with PdCl2 in hot dimethylsulphoxide to give [PdCl(mpt)]. The structure was determined by X-ray analysis. The thioamide is metallated at C(2) to act as an S528-01C528-02S tridentate anionic ligand. There is appreciable steric repulsion between the benzene ring H(4, 6) and the dimethylamino groups. The hydrogens and the methyl groups mutually deviate from the coordination plane in opposite directions. The stability of the fused 5,5-membered chelate ring formed by the S528-03C528-04S ligand seems to overcome the steric hindrance. Derivatives were prepared by replacement of the chloride ion with iodide, diethyldithiocarbamate, 4-tert-butylpyridine, or tri-n-butylphosphine, and characterized spectroscopically. The S528-05C528-06S-fused chelate ring was maintained in these derivatives. 相似文献
14.
á. Keszler Béla Kazinczy László Kótai 《Fresenius' Journal of Analytical Chemistry》1999,364(4):328-332
N,N’-dimethyl-N,N’-diphenylcarbamide (centralite) extracted from building materials was quantitated using ion trap GC-MS
detection technique. Both linearity and standard deviation of the calibration curve were dependent on the conditions of the
mass spectral detection. The most precise calibration has been achieved by quantification of a mass ion not participating
in secondary reactions and which is produced via single fragmentation. The best recovery of centralite was obtained after either 30 min of normal extraction with toluene
at 60 °C or 10 min of ultrasonic extraction with chloroform at room temperature. Using the latter method resorption processes
might cause decrease in efficiency of the recovery at longer extraction time.
Received: 3 July 1998 / Revised: 5 November 1998 / Accepted: 26 January 1999 相似文献
15.
First‐principles calculations were carried out on recently synthesized Re2 and Re3 as well as hypothetical Tc and Mn nitrides. It is found that structure and covalent bonds play an important role in determining mechanical properties. Under a large strain along (0001)〈101 0〉direction, Re2N undergoes a phase transformation with a slight increase in ideal shear strength. On the other hand, it is transformed into a phase with weaker mechanical properties, if the strain is along Re2〈1 21 0〉 direction. Mn2N can be synthesized under moderate conditions due to its more negative formation energy. Re2N, Re3N, and Mn2N show structure‐related mechanical property under larger strains to ReB2 but exhibit much lower ideal strengths, which is attributed to the larger ionicity of cation–anion bond. Three‐dimensional framework of strong covalent bonds is thus highly recommended to design superhard materials. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011 相似文献
16.
《Journal of Inorganic and Nuclear Chemistry》1978,40(2):253-256
Under carefully controlled experimental conditions and with the maintenance of completely anhydrous systems, crystalline lanthanide complexes with nitrogen-donor ligands N,N′-dimethylethylenediamine (dmed) and N,N,N′,N′-tetramethylethylenediamine (tmed) have been isolated. Stoichiometric compositions of the products are Ln(dmed)2Cl3 (Ln = Sm, Er, Yb), Ln(dmed)2(NO3)3 (Ln = Pr, Sm), Gd(dmed)(NO3)3, Ln(tmed)Cl3 (Ln = La, Pr, Nd, Sm, Ho, Er) and Ln(tmd)(NO3)3·xCH3CN (Ln = Nd, Er, Ho; x = 0, 1). Calorimetric studies indicate that the dmed complexes do not form in a stepwise fashion in acetonitrile, but rather that higher-order species form in solution. 相似文献
17.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1980,36(3):265-272
The i.r. and Raman spectra of N,N,N′,N′-tetramethyl-p-phenylenediamine and the perchlorate salt of its radical cation have been recorded. The frequencies of the fundamental vibrations of the neutral molecule and the radical ion have been computed using force constants transferred from smaller molecules. The observed spectral bands have been assigned and the ionization band shifts have been discussed. Most of the significant band shifts have been observed in the 1700-1300 cm−1 range. The calculations showed that they are primarily due to the variation of the bond strengths of the ring CC and ring-N bonds. 相似文献
18.
Teixeira Luiz Flávio Lopes Mazzilli Barbara Paci 《Journal of Radioanalytical and Nuclear Chemistry》2019,320(3):551-560
Journal of Radioanalytical and Nuclear Chemistry - The Cananéia-Iguape system is a complex of lagoon and estuarine channels located in the south of state of São Paulo. This system... 相似文献
19.
Jordanka Petrova Snejana Momchilova Marko Kirilov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):173-178
Abstract The high erythro-stereoselective reaction of Li-tetramethyldiamides of arylmethanephosphonic acids with carbonyl compounds is used for synthesis of (Z)-alkenes by thermolysis of the erythro-adducts as well as in acidic media. 相似文献
20.
S. N. Gridchin V. M. Nikol’skii 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2014,88(4):573-577
The stepwise dissociation constants of tetramethylenediamine-N,N,N′,N′-tetraacetic acid (H4L) are determined by means of potentiometry at 298.15 K and ionic strength values of 0.1, 0.5, and 1.0 (KNO3). The heat effects of the dissociation of the betaine groups of the complexone are measured by direct calorimetry. The standard thermodynamic characteristics of the protolytic equilibria of H4L are calculated via combined use of the results from thermochemical and potentiometric studies performed under identical experimental conditions. Our results are compared with the corresponding data on relative compounds. 相似文献