首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
在核反应堆中辐照高纯铼金属带 ,185Re和187Re通过 (n ,γ)反应后 ,经 β衰变产生186Os和188Os ,用H2 O2 和H2 SO4 将Re带溶解并同时将186Os和188Os蒸馏出 ,首先用 2 0 %NaOH溶液吸收 ,然后再将碱吸收液重新蒸馏 ,最后将186Os和188Os混合同位素保存在 2 5 %HCl介质中 ,用负离子热电离质谱仪 (NTIMS)标定其含量及同位素丰度。结果表明 ,91.4mg的高纯铼金属带 ,在辐照的累积通量为 1.32× 10 18n/cm2时 ,可产生Os 8.46 μg ,其186Os和188Os的同位素丰度分别为 6 0 .89%和 38.6 3%  相似文献   

2.
3.
综述了近年来锇络合物用于催化烯烃加氢和异构化反应的研究进展。 Os催化剂在H2分子和转移加氢二个方面用于烯烃加氢反应均表现出较高的活性和选择性。因此它有望成为有机合成中的一个强有力的工具。  相似文献   

4.
一、引言利用四氧化锇的高度挥发性,在氧化体系中蒸馏出锇,是一种经典的化学分离方法。然而,在无载体条件下,实现超痕量锇的分离,还未见报导。元素锇的行为在宇宙化学的研究中具有重要意义,在实际工作中,常希望测定用普通质谱法无法测定的~(184)Os/~(190)Os之比值;而且,由于样品珍贵,同一份样品要供几种方法检验,因此,不希望在分析后改变样品原始的同位素组成,鉴于这种考虑,我们尝试用无同位素载体的放化分离活化分析法来研究这两种来自不同核合成过程的产物之丰度比。  相似文献   

5.
Reaction of the activated cluster [Os3(CO)11(CNMe)] with primary arsine AsH3 forms the arsinidine compound [H2Os33-AsH)(CO)11] (1a, 1b), which on further reaction with [Os3(CO)11(NCMe)] yields [(CO)11Os3As(Os3(CO)9H3)] (2) and with [H2Os3(CO)10] yields [H2Os3(CO)9As(Os3(CO)9H2)] (3). Similarly [H2Os3(CO)10] reacts with AsH3 at room temperature to afford 3 in good yields. Thermal degradation and rearrangement of 2 gives the pentanuclear cluster [H2Os5(CO)17AsH] (4).  相似文献   

6.
综述了近年来锇络合物用于催化烯烃加氢和异构化反应的研究进展.Os催化剂在H_2分子和转移加氢二个方面用于烯烃加氢反应均表现出较高的活性和选择性.因此它有望成为有机合成中的一个强有力的工具.  相似文献   

7.
The electronic absorption and circular dichroism spectra of the complexes produced by the one-, two- and three-electron reduction of Δ-[Os(bipy)3]2+ are reported for the first time. The spectra confirm that, as in the cases of the FeII and RuII analogues, the electrons are localised on the bipyridine ligand and the complexes are correctly formulated [Os(bipy)2(bipy)]+, [Os(bipy)(bipy)2]0 and [Os(bipy)3]. The absorption spectra of the series of fully reduced complexes [M(bipy)3]: M  Fe, Ru, Os are compared.  相似文献   

8.
Os(Ⅱ)配合物的电化学性质及其电子能级结构   总被引:3,自引:1,他引:3  
采用电化学循环伏安法和荧光光谱研究了系列Os配合物的电化学性质及分子结构对其电子能级结构的影响。  相似文献   

9.
Microwave heating allows for the high-yield, one-step synthesis of the known triosmium complexes Os3(μ-Br)2(CO)10 (1), Os3(μ-I)2(CO)10 (2), and Os3(μ-H)(μ-OR)(CO)10 with R = methyl (3), ethyl (4), isopropyl (5), n-butyl (6), and phenyl (7). In addition, the new clusters Os3(μ-H)(μ-OR)(CO)10 with R = n-propyl (8), sec-butyl (9), isobutyl (10), and tert-butyl (11) are synthesized in a microwave reactor. The preparation of these complexes is easily accomplished without the need to first prepare an activated derivative of Os3(CO)12, and without the need to exclude air from the reaction vessel. The syntheses of complexes 1 and 2 are carried out in less than 15 min by heating stoichiometric mixtures of Os3(CO)12 and the appropriate halogen in cyclohexane. Clusters 36 and 810 are prepared by the microwave irradiation of Os3(CO)12 in neat alcohols, while clusters 7 and 11 are prepared from mixtures of Os3(CO)12, alcohol and 1,2-dichlorobenzene. Structural characterization of clusters 2, 4, and 5 was carried out by X-ray crystallographic analysis. High resolution X-ray crystal structures of two other oxidative addition products, Os3(CO)12I2 (12) and Os3(μ-H)(μ-O2CC6H5)(CO)10 (13), are also presented.  相似文献   

10.
A high efficiency and low toxicity radiosensitizer,OsN(PhenOH)Cl_3,was designed and synthesized through substituent regulation.To the best of our knowledge,this is the first osmium-based coordination complex radiosensitizer.The experimental results shown that this radiosensitizer induced G2/M cell cycle arrest mainly through induction of intracellular ROS overproduction.  相似文献   

11.
A high efficiency and low toxicity radiosensitizer,OsN(PhenOH)Cl_3,was designed and synthesized through substituent regulation.To the best of our knowledge,this is the first osmium-based coordination complex radiosensitizer.The experimental results shown that this radiosensitizer induced G2/M cell cycle arrest mainly through induction of intracellular ROS overproduction.  相似文献   

12.
Previously unknown μ-acyl osmium clusters containing simultaneously permethyl-metallocenyl and Os3 cluster fragments were synthesized. The IR, UV, NMR (1H and13C), and FAB-MS spectra were examined. Protonation of the clusters proceeds at the metal atom of the metallocenyl fragment. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 180–183, January, 1999.  相似文献   

13.
New high yield routes to the high nuclearity hydrido carbonyl clusters [H5Os10(CO)24]- and [H4Os10(CO)24]2-, model systems for the chemisorption of CO and H2 on metal surfaces, are reported. [H5Os10(CO)24]- is obtained in good yields by hydrogenation (1 atm) at 200°C of physisorbed [Os(CO)3(OH)2]n whereas in refluxing ethylene glycol solution, that is less acidic than the silica surface, [H4Os10(CO)24]2- is obtained in high yield starting from [Os(CO)3(OH)2]n or, more conveniently, from -[Os(CO)3Cl2]2 in the presence of the stoichiometric amount of sodium carbonate. The quantitative equilibrium
is confirmed.  相似文献   

14.
A series of novel chiral complexes with ,1and ,2 coordination of organic ligands were prepared by reactions of Os3(CO)11(MeCN) and (-H)Os3(CO)10(-OH) withL--serine ethyl ester and ethanolamine. The diastereomeric cluster complexes with serine ligands were separated by crystallization or chromatography. The structures of the compounds obtained were confirmed by1H NMR and IR spectroscopy, mass-spectrometry, elemental analysis, and X-ray diffraction analysis.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 525–530, March, 1994.  相似文献   

15.
In this work X-ray production cross-sections’ measurements, Lι, Lα, Lβ and Lγ, of Yb, Lu, Os and Pt elements have been studied at energies in the range 9.572–14.384 keV and the effect of Coster–Kronig transitions on fluorescence cross-sections for L X-ray line has been obtained. From these studies absolute values of L X-ray cross-sections have been calculated with incorporation of the enhancement due to the Coster–Kronig effect. The experimental enhancement factors tend to be smaller than those predicted by theory.  相似文献   

16.
本文报道了一种双核锇Os(Ⅱ)配合物[Os (η6-bip)(1,3-bib) Cl]2Cl2bib-Os),其中η6-bip=η6-联苯,1,3-bib=1,3-二(1H-咪唑-1-基)苯。并通过1H NMR和ESI-MS进行基础表征。配合物bib-Os具有良好的脂溶性,易在细胞中积累。配合物bib-Os对人卵巢癌A2780细胞表现出高效的抗增殖活性,可产生活性氧(ROS)并诱导线粒体损伤。脂质过氧化物(LPO)积累、谷胱甘肽(GSH)消耗和谷胱甘肽过氧化物酶4(GPX4)下调表明,配合物bib-Os诱导A2780细胞死亡的主要机制是铁死亡,bib-Os是第一例诱导肿瘤细胞铁死亡的Os金属配合物。  相似文献   

17.
本文报道了一种双核锇Os(Ⅱ)配合物[Os (η6-bip)(1,3-bib) Cl]2Cl2(bib-Os),其中η6-bip=η6-联苯,1,3-bib=1,3-二(1H-咪唑-1-基)苯。并通过1H NMR和ESI-MS进行基础表征。配合物bib-Os具有良好的脂溶性,易在细胞中积累。配合物bib-Os对人卵巢癌A2780细胞表现出高效的抗增殖活性,可产生活性氧(ROS)并诱导线粒体损伤。脂质过氧化物(LPO)积累、谷胱甘肽(GSH)消耗和谷胱甘肽过氧化物酶4(GPX4)下调表明,配合物bib-Os诱导A2780细胞死亡的主要机制是铁死亡,bib-Os是第一例诱导肿瘤细胞铁死亡的Os金属配合物。  相似文献   

18.
Reduction of the heptaosmium cluster [Os7(CO)21] With [Et4N][NH4) gives the cluster dianion [Os7(CO)20]2–,1, in high yield. The reaction of the dianion with [AuPR 3Cl] (R=Et or Ph) in the presence of TlPF6 forms [Os7((CO)20(AuPR 3)2] [R=Et (2a);R = Ph(2b)] in 80% yield, while the corresponding reaction with (Os(C6H6)(CH3CN)3]2+ gives [Os8(CO)20 ( 6-C6H6)] (3) in reasonable yield (ca. 30%). The dianion,1, and the clusters2 and3 have been fully characterized by bout spectroscopic and crystallographic methods. The crystal structure of the [Ph4P]+ salt of1 shows that the metals in the anion adopt a capped octahedral geometry, with all twenty carbonyl ligands in terminal sites. The metal core geometry in2a is best described as a tricapped octahedron, and is based on the structure of the dianion1 with two adjacent octahedral faces capped by the Au atoms of the two AuPEt3 groups. In a similar fashion, the geometry of3 is related to that of1 with the addition of an Os(C6H6) unit capped to a triangular face, to give a bicapped octahedral framework.  相似文献   

19.
Oxo(tert-butylimido) or bis(tert-butylimido)osmium(VI) porphyrins Os(Por)(O)(NBut) and Os(Por)(NBut)2, [Por=meso-tetrakis(p-tolyl)porphyrinato (TTP) and meso-tetrakis(4-chlorophe-nyl)porphyrinato (4-Cl-TPP)] were synthesized by air oxidation of bis(tert-butylamme)osmium(II) porphyrins [Os(Por)(H2NBut)2 (Por=TPP, 4-Cl-TPP], depending on whether tert-butylamine is present. The bis(tert-butylamine)ruthenium(II) porphyrins [Ru(Por)(H2NBut)2, Por=TTP, 4-Cl-TPP] can undergo bromine oxidation to give oxo(tert-butylimido)ruthenium(VI) complexes in quantitative yields. All these new complexes were characterized by 1H NMR, UV-Visible and IR spectroscopy. The X-ray crystal structures of Os(TTP)(O)(NBut).EtOH and Os(4-Cl-TPP)(NBut)2 have been determined. Crystal data: for Os(TTP)(O)(NBut).EtOH: monoclinic, space group P21/c, a=1.3546(6) nm, b=2.3180(3) nm, c=1.6817(3) nm, B=90.84(2), V=527.97(1) nm3, Z=4. The Os=O and Os=NBut distances in Os(TTP)(O)(NBut).EtOH are 0.1772(7) nm and 0.1759(9) nm, respectively. The av  相似文献   

20.
采用自旋限制和非限制B3LYP/UB3LYP方法分别优化了系列Os(Ⅱ)二亚胺配合物[Os(L)2(CN)2(phen)][phen=1,10-邻二氮杂菲;L=PH3(1),二甲基亚砜(DMSO)(2)]及[Os(PH3)2(phen)Br2](3)的基态和激发态几何构型.通过TD-DFT方法结合PCM溶剂化模型计算了配合物1~3在二氯甲烷溶液中的吸收和发射光谱并指认了相应的跃迁性质.通过理论化学计算,揭示了π酸配体及π碱配体对配合物磷光发射性质的影响及原因.并进一步解释了配合物3易于在Os-Br键处断裂而发生反应的量子化学机理.对配合物在不同溶剂中的磷光发射性质的计算表明,溶剂对配合物的量子产率存在着影响并且配合物具有溶剂化显色效应.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号