排序方式: 共有31条查询结果,搜索用时 46 毫秒
1.
Ion-exchange resins, especially chelating resins are used for pre-concentration of metal ions in trace analysis as well as
for radiochemical separations following neutron activation of a variety of environmental samples. As part of a systematic
study of the sorption characteristics of chelating resins, sorption of Zn(II) and Cd(II) by three chelating resins were studied
for various acid conditions in nitrate and chloride media. Both Zn(II) and Cd(II) showed similar behavior. Under higher acid
conditions, maximum sorption occurred in 3M HCl solutions. Under low acid conditions, the sorption increased with pH. Chelex
100 gave the highest sorption among the three resins.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
R. N. Ceo M. R. Kazerouni K. Rengan 《Journal of Radioanalytical and Nuclear Chemistry》1993,172(1):43-48
Sorption of Ag+, Ag(NH3)
n
+
, and anionic complexes of silver with chloride and thiocyanate ions by Chelex 100, a chelating resin, were investigated systematically. The results are utilized to interpret the seemingly contradictory data available in the literature 相似文献
3.
The extraction characteristics of isooctyl thioglycolate (IOTG), a chelating agent, in various diluents has been studied with
respect to the metal ions, tin(IV) and antimony(III), in hydrochloric acid medium. It is concluded that antimony(III) can
be separated from tin(IV) with 85% yield and with a decontamination factor of at least 1·105 using IOTG diluted with petroleum ether and 3M HCl medium. Tin(IV) can be separated conveniently from antimony(III) in 2M
HCl with 95% yield and with a decontamination factor greater than 7·105 using IOTG diluted with carbon tetrachloride. 相似文献
4.
The distribution coefficients (DC) for HgCl
4
2–
, Hg(SO4)
2
2–
, Hg(NO3)
4
2–
, Ag+, Ag(SCN)
2
–
and Ag(NH3)
2
+
between aqueous solutions and Dowex A-1 were measured in varying hydrogen ion concentrations. The DC of Ag+ in the NO
3
–
media was very low (4 to 6). The DC for the Ag(SCN)
2
–
complex decreased as pH increased. The Ag(NH3)
2
+
complex had a constant DC of about 65 from pH 8 and above. The trend observed for three mercury complexes in HCl, H2SO4 and HNO3 was similar; the DC decreased steadily from 0.1M to 6M. The HgCl
4
2–
complex had the highest DC (9000) while the Hg(NO3)
4
2–
complex had the lowest DC (2000). 相似文献
5.
Gunasekaran Balamurugan Sundarraman Balaji Rengan Ramesh Nattamai S.P. Bhuvanesh 《应用有机金属化学》2019,33(1)
A panel of six new arene Ru (II)‐NHC complexes 2a‐f , (NHC = 1,3‐diethyl‐(5,6‐dimethyl)benzimidazolin‐2‐ylidene 1a , 1,3‐dicyclohexylmethyl‐(5,6‐dimethyl)benzimidazolin‐2‐ylidene 1b and 1,3‐dibenzyl‐(5,6‐dimethyl)benzimidazolin‐2‐ylidene 1c ) were synthesized from the transmetallation reaction of Ag‐NHC with [(η6‐arene)RuCl2]2 and characterized. The ruthenium (II)‐NHC complexes 2a‐f were developed as effective catalysts for α‐alkylation of ketones and synthesis of bioactive quinoline using primary/amino alcohols as coupling partners respectively. The reactions were performed with 0.5 mol% catalyst load in 8 h under aerobic condition and the maximum yield was up to 96%. Besides, the different alkyl wingtips on NHC and arene moieties were studied to differentiate the catalytic robustness of the complexes in the transformations. 相似文献
6.
A simple route to synthesize triphenylphosphinopalladium(II) thiosemicarbazonato complex has been described. Elemental analysis, spectral (IR, NMR) and single crystal X-ray diffraction techniques were employed for the complete characterization of the complex. The latter was found to be effective catalyst for carbon–carbon cross-coupling reaction of aryl- and heteroarylboronic acids with aromatic and heteroaromatic aldehydes to form the corresponding diaryl ketones. The influence of reaction parameters such as solvent, base, reaction temperature and catalyst loading was also investigated. 相似文献
7.
Cerenkov counting is often regarded as a modified version of liquid scintillation counting in which chemical quenching is
not manifested. However, the mechanism of Cerenkov counting is such that changes in the concentration of reagents in the counting
medium results in changes in Cerenkov counting efficiency. Large changes in counting efficiency occur for nuclides with low
average beta energy values (Ēβ). The percent increase in Cerenkov counting efficiency in 4M HCl (relative to water) for various nuclides was found to be
a smooth function of Ēβ. The relative change in counting efficiency for24Na,32P,42K and204Tl in HCl, NH4Cl and/or NaCl media are presented. The data emphasizes the need to keep the concentration of various chemicals in Cerenkov
counting media constant, especially for nuclides with low Ēβ, values, in order to reproduce counting efficiency. 相似文献
8.
E. Mothi Mohamed Samraj Muralidharan Krishnaswamy Panchanatheswaran Rengan Ramesh John N. Low Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(7):o367-o369
Molecules of the title compound, alternatively called (R,R)‐N,N′‐bis(3‐methoxysalicylidene)‐trans‐cyclohexane‐1,2‐diamine, C22H26N2O4, contain two intramolecular O—H⃛N hydrogen bonds and adopt a conformation with approximate twofold rotational symmetry. The molecules are linked by three C—H⃛O hydrogen bonds [H⃛O = 2.45–2.55 Å, C⃛O = 3.329 (2)–3.398 (2) Å and C—H⃛O = 142–172°] into a continuous framework. 相似文献
9.
Aravind Kumar Rengan Gopal Kundu Rinti Banerjee Rohit Srivastava 《Particle & Particle Systems Characterization》2014,31(3):398-405
Numerous gold nanostructures have the potential for photothermal therapy in cancers. Here, gold nanocages and gold nanoshells are synthesized, the sizes of which are fine‐tuned for a response at 750 nm wavelength. Their photothermal therapeutic efficiency is compared at gold concentration of 100 lg mL?1 using a near‐infrared laser (750 nm). The biocompatibility for varying concentrations of gold (1 to 100 lg mL?1) is performed in a normal cell line and laser‐mediated cell cytotoxicity for varying time intervals (7.5 and 10 min) is carried out in breast cancer cells. This study shows that when analyzed under similar conditions, the gold nanocages show better biocompatibility and are more efficient in near‐infrared absorption and photothermal conversion in comparison with conventional gold nanoshells. When subjected to photothermal laser ablation of breast cancer cell line for 7.5 min and 10 min, the nanocages are able to induce 62.92 ± 3.25% and 96.41 ± 3.04% reduction in cell viability, respectively, in comparison to nanoshells, in which a 43.35 ± 1.91% and 79.89 ± 4.74% reduction in cell viability is observed. The current study shows that the gold nanocages can outperform gold nanoshells and effectively kill cancer cells without any significant cytotoxic effect on normal cells. 相似文献
10.
A simple route to synthesise palladium(II) complexes from the reaction of N-substituted pyridine-2-thiocarboxamide ligands and PdCl(2)(PPh(3))(2) has been developed. The new complexes are very soluble in common solvents and have been fully characterised (elemental analysis, FT-IR, (1)H, (31)P, (13)C-NMR), including an X-ray diffraction analysis. The molecular structures of all the complexes were determined and reveal the presence of square planar geometry around Pd with little distortion. The complexes were tested in the Suzuki coupling of electronically deactivated aryl and heteroaryl bromides and were found to have much greater activity, without using any promoting additives or phase transfer agent under aerobic conditions. Higher reaction rates are obtained by varying R substituents on the aromatic ring of pyridine-2-thiocarboxamide. The effect of other variables on the cross-coupling reaction, such as temperature, solvent and base, is also reported. 相似文献