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 62 毫秒
1.
在NaX分子筛超笼中通过RuⅢ(NH3)6同CO+H2反应合成了[Ru6(CO)18]2-原子簇阴离子.原子簇阴离子上的羰基配体在氢气存在时具有一定的13CO同位素交换活性.EXAFS的数据表明,80─90%的钌原子在NaX分子筛中以[Ru6(CO)18]2-的方式存在.分子筛笼中的原子簇阴离子在氧化气氛下解离成单核钌羰基物种Ru1(CO)2,两者的结构在氧化(O2)及还原(CO+H2)条件下可以进行可逆转化.  相似文献   

2.
采用单层分散法将Ru3(CO)12引入NaY分子筛的孔道中,借助FTIR,EXAFS和UV-VIS等实验手段对其进行了测定,发现Ru3(CO)12完整地分布于分子筛的超笼内,抽空会导致在保持金属骨架情况下的部分脱羰,同时伴随着桥式羰基谱带的出现,这意味表面次羰基合物的形成,原子簇上的羰,同时伴随着桥式羰基谱带的出现,这意味着表面次羰基加合物的形成,原子簇上的羰基配体可以同13CO同位素进行交换反应  相似文献   

3.
担载于ZrO2上的Ru3(CO)12-Fe(CO)9混合簇的红外光谱表明,Ru3(CO)12以Ru(CO)2O2表面络合物存在.混合族在真空中随温度升高而发生脱羰基作用,500℃左右羰基完全脱掉;以Al2O3为载体者其羰基不易脱除,升高温度出现多种羰基带.混合簇中的Fe2-(CO)9极易脱羰基.担载混合簇在Ar气中进行TPDE时,低温时以脱羰基为主,高于150℃时发生表面歧化反应而生成CO2;在H2气中,低温时仍以脱羰基为主,高于150℃时发生表面加氢反应而生成CH4.混合簇的脱羰基和表面反应能力与Ru/Fe比及载体有关.担载混合簇在CO加氢反应中以Ru(CO)2O2和分散Fe存在,还出现-CHx多种表面物种.  相似文献   

4.
分子筛笼内铂羰基簇合物在CO+NO反应中的催化研究   总被引:1,自引:1,他引:1  
研究了NaY分子筛超笼内包容的Pt羰基簇合物催化剂在CO+NO反应中的催化性能。「Pt12(CO)24」^2-/NaY和「Pt9(CO)13」^2-/NaY在此反应中表现出比较高的活性。N2O被认为是CO+NO反应的中间产物,同时笼内羰基簇合物还表现了比SiO2负载的簇合物好的热稳定性,动力学研究表明,在「Pt12(CO)24」^2-/NaY上,NO被还原和N2O生成的反应级数,相对于CO分压为小  相似文献   

5.
担载Ru3(CO)12-Fe2(CO)5混合簇的脱羰基作用和表面加氢反应   总被引:1,自引:0,他引:1  
担载于ZrO2上的Ru3(CO)12-Fe2(CO)9混合簇的红外光谱表明,Ru3(CO)12以Ru-(CO)2O2表面络合物存在。混合簇在真空中随温度升高而发生脱羰基作用,500℃左右羰基完全脱掉;以Al2O3为载体者其羰基不易脱除,升高温度出现多种羰基带。混合簇中的Fe2-(CO)9极易脱羰基。  相似文献   

6.
在NaY分子筛超笼内合成了桔黄色的[Pt9(CO)16]^2-和深绿色的[Pt12(CO)24]^2-簇合物。前者给出2056和1798cm^-1的线式和桥式羰基特征红外谱带;后者给出2080和1824cm^-1谱带。与在THF溶液中结果相比,NaY内合成的羰基簇合物的线式vco向高波数位移,而桥式vco向低波数位移。EXAFS为Pt羰基簇合物在分子筛内的规整形成提供了证据。NaY内Pt9和Pt1  相似文献   

7.
SHIP-IN-BOTTLESYNTHESISANDCHARACTERIZATIONOFRu_4H_4(CO)_(12)ENTRAPPEDWITHINNaYZEOLITEAnMingLIU;YiDeXu;TakafumiSHIDO;MasaruICHI?..  相似文献   

8.
以Fe_3(CO)_(12)为母体,以活性氧化铝或活性炭为载体制备了负载型氨合成催化剂.在固定床管式流动反应系统中测定了催化活性,并与以Ru_3(CO)_(12)和RuCl_3·xH_2O为母体的负载催化剂以及低温高活性氨合成工业催化剂的活性进行了对比。结果表明:以活性炭为载体的Fe_3(CO)_(12)催化剂在15MPa、400℃以上表现出很高活性,且每克纯活性组分的催化活性在某些温度下比当前活性较高的工业熔铁催化剂的活性要高得多,但低温常压下几乎无活性。负载钉催化剂在低温常压下即显活性,且以RuCl_3·xH_2O为母体,比以Ru_3(CO)_(12)为母体的负载钌催化剂活性高。  相似文献   

9.
本文研究了两种水溶性钌-膦配合物RuCl_2(TPPTS)_3和Rucl_2(CO)_2(TPPTS)_2[TPPTS为:P(m-C_6H_4SO_3Na)_3]的合成,在水相和有机相组成的两相催化体系中,考察了它们衍生出的活性物种和以RuCl3-TPPTS原位合成的活性物种对肉桂醛的选择加氢性能,并对反应温度(20—80℃),氢压(2—6MPa),催化剂浓度(1.12×10~(-3)~4.50×10~(-3)mol/L),配体TPPTS浓度(9.0×10~(-3)~5.4×10~(-2)mol/L),表面活性剂浓度和反应时间的变化对选择加氢反应的影响进行了详细研究。实验结果表明,RuCl_3-TPPTS原位合成配合物的催化加氢活性最高,而在金属Ru上羰基的配位将使加氢活性降低,表面活性剂CTAB是有效的促进剂,它的加入可大大提高加氢活性,选择适当的CTAB浓度,在反应结束后水相与有机相分层迅速,有利于Ru催化剂的分离,在所考察的反应条件下,肉桂醛选择加氢生成肉桂醇的转化率大于80%,选择性达96%以上。  相似文献   

10.
对一类新型阴离子络盐M~+[(μ-CO)(μ-RS)Fe_2(CO)_6]~-(M~+=Et+3NH~+,Li~+,Na~+,MgX~+)的合成、结构和反应进行了综述。该类络盐可由硫醇或硫酚盐RS~-M~+与Fe_3(CO)_(12)在THF中合成并于原位(insitu)反应。经单晶X射线衍射分析证实其阴离子中的Fe_2SC骨架具蝶状结构,它显示高度的亲核反应活性,能同多种亲电底物反应。典型的底物包括卤代不饱和烃、酰氯、炔烃、磷、砷卤代物、二硫化碳、二氯化二硫、单质硫或硒及烃基卤化汞等。该类络盐业已成为一种有效试剂,它在新颖金属有机和原子簇化合物的合成中具有广泛的应用价值。  相似文献   

11.
A new biosensor method was developed to determine residual carbofuran in tomatoes in a rapid and convenient fashion based on immobilizing acetylcholinesterase (AChE) on an electrode modified by concanavalin A (Con A)/polydopamine (PDA)-reduced graphene oxide (RGO)-gold nanoparticle (GNP) nanocomposites. The specific binding between Con A and AChE was investigated by the Ellman method and cyclic voltammetry (CV). The synthesis of nanocomposites was monitored by ultraviolet-visible absorption spectroscopy, scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). The results showed that, due to the specific binding and good electrical conductivity, the biosensor had 2.2 times higher bioactivity, leading to high sensitivity with a low Michaelis constant of 0.10?mM. Parameters that affect the response of the biosensor, such as the pH, enzyme loading, ionic concentration, and inhibition time, were optimized. When used for the detection of carbofuran, this biosensor showed a wide range of applicability from 5?µg/kg to 40?µg/kg with a detection limit of 0.012?µg/kg. In addition, the biosensor demonstrated good recovery values of 101% and 90% for 10?µg/kg and 100?µg/kg of the analyte, good stability, high repeatability, and a rapid detection time of 20?min for carbofuran in tomatoes, which provides significant advantages for future analysis.  相似文献   

12.
The complexes [Ni(PEt 3)2 dtc]X (1) and Ni(PEt 3)Xdtc (2) (dtc=S2CNEt 2,X=Cl, Br, I) have been prepared. As conductivity, susceptibility, UV and IR measurements show, the cations [Ni(PEt 3)2 dtc]+ of1 and the complexes2 at ambient temperature have square-planar structure. We suppose there might exist an equilibrium for2 between square-planar and tetrahedral configuration.
  相似文献   

13.
Bis(tetramethylammonium), bis(tetrabutylammonium), and bis(tetraphenylarsonium) dihydrohexaoxoxenonates(VIII) were obtained in an aqueous solution and in acetonitriie. The rate constants of their decomposition were determined.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 184–185, January, 1995.This work was carried out with financial support from the International Scientific Foundation (Grant REI 000).  相似文献   

14.
Reaction of the N-(2-pyridyl)carbonylaniline ligand (L) with Cu(NO3)2, Cu(ClO4)2, Zn(ClO4)2, Ni(NO3)2 and PdCl2 gives complexes with stoichiometry [Cu(L)2(H2O)2](NO3)2, [Cu(L)2(H2O)2](ClO4)2, [Zn(L)2(H2O)2] (ClO4)2, [Ni(L)2(H2O)Cl](NO3) and PdLCl2. The new complexes were characterized by elemental analyses and infrared spectra. The crystal structures of [Cu(L)2(H2O)2](NO3)2, [Cu(L)2(H2O)2](ClO4)2, and [Zn(L)2(H2O)2](ClO4)2 were determined by X-ray crystallography. The cation complexes [M(L)2(H2O)2] contain copper(II) and zinc(II) with distorted octahedral geometry with two N-(2-pyridyl)carbonylaniline (L) ligands occupying the equatorial sites. The hexa-coordinated metal atoms are bonded to two pyridinic nitrogens, two carbonyl oxygens and two water molecules occupying the axial sites. Both the coordinated water molecules and uncoordinated amide NH groups of the N-(2-pyridyl)carbonylaniline (L) ligands are involved in hydrogen bonding, resulting in infinite hydrogen-bonded chains running in one and two-dimensions.  相似文献   

15.
The synthesis of new inorganic pigments has been investigated with the goal of preparing heat stable and anticorrosive pigments. The synthesis is based on a thermal procedure making use of the reversible transformation of cyclo-tetraphosphates(V) to higher linear phosphates(V). New binary condensed phosphates were synthesized based on the results of thermal analysis. These compounds represent new environmentally-friendly special pigments. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

16.
New complexes of the formulae K3[RhL 3]·2 H2O, [PdL]·H2O and [M(LH2)Cl2] [whereM = Pd, Pt andLH2 = bis(o-aminobenzenesulfonyl)ethylenediamine] have been prepared and characterized by conductivity measurements, thermogravimetric analysis, X-ray powder patterns and IR, Ligand Field and1H-NMR spectroscopy.
Rhodium(III), Palladium(II)- und Platin(II)-Komplexe mit Bis(o-aminobenzolosulfonyl)ethylendiamin (Kurze Mitteilung)
Zusammenfassung Neue Komplexe der allgemeinen Formeln K3[RhL 3]·2H2O, [PdL]·H2O und [M(LH2)Cl2] mitM = Pd, Pt undLH2 = Bis(o-aminobenzolosulfonyl)ethylendiamin wurden dargestellt und mit Konduktionsmessungen, thermogravimetrischen Analysen, Röntgenstrukturanalysen, IR, Ligandfeld- und1H-NMR-Spektroskopie charakterisiert.
  相似文献   

17.
A selective method has been developed for extraction chromatographic studies of aluminium(III) and its separation from several metal ions with a chromatographic column containing N-n-octylaniline (liquid anion exchanger) coated on silanized silica gel as a stationary phase. The aluminium(III) was quantitatively extracted with the 0.065 mol/L N-n-octylaninine from 0.013 to 0.05 mol/L sodium succinate at a flow rate of 1.0 mL/min. The extracted metal ion has been recovered by eluting with 25.0 mL of 0.05 mol/L hydrochloric acid and estimated spectrophotometrically with aurintricarboxylic acid. The effects of the acid concentration, the reagent concentration, the flow rate and the eluting agents have been investigated. The log-log plots of distribution coefficient (KdAl(III)) versus N-n-octylaniline concentrationin 0.005 and 0.007 mol/L sodium succinate gave theslopes 0.5 and 0.7 respectively and showed theprobable composition of theextracted species was 1:1 (metal to amine ratio) and the nature of extracted species is [RR''NH2+ Al succinate2-] org. .The extraction of aluminium(III) was carried out in the presence of various ions to ascertain the tolerance limit of individual ions. Aluminium(III) has been separated from multicomponent mixtures, pharmaceutical samples and synthetic mixtures corresponding to alloys. A scheme for mutual separation of aluminium(III), indium(III), gallium(III) and thallium(III) has been developed by using suitable masking agents. The method is fast, accurate and precise.  相似文献   

18.
手性二噁唑啉吡啶铁和镍配合物的制备与表征   总被引:1,自引:0,他引:1  
Tridentate bis(oxazolinylpyridine)(1) reacted with nickel chloride or ferrous chloride in anhydrous ethanol to form bis(oxazolinylpyridine) Nickel(Ⅱ) and Iron(Ⅱ) complexes. The stable solid complexes were characterized with IR, UV, MS, XPS and elemental analysis. No stable complexes were formed with bidentate bis(oxazoline)(2) ins- tead of bis(oxazolinylpyridine).  相似文献   

19.
IntroductionTheabilityofdithiocarbamate(dtc)bindingtometalshasbeenknownformanyyears .Itformschelateswithvirtu allyalltransitionmetals.1Thebidentateanionisalsowellknownasabridgebetweentwotransitionmetalcenters.2 Wa ter solubledialkyldithiocarbamatecomplexes…  相似文献   

20.
The reaction of the potassium salt of the N-(thio)phosphorylated thioureas AdNHC(S)NHP(O)(OiPr)2 (HLI , Ad = Adamantyl) and MeNHC(S)NHP(S)(OiPr)2 (HLII ) with Co(II) and Zn(II) in aqueous EtOH leads to [MLI,II 2] chelate complexes. They were investigated by UV-vis, 1H and 31P NMR spectroscopy, and microanalysis. The molecular structures of [MLI 2] were elucidated by single crystal X-ray diffraction analysis. The metal centers in both complexes are found to be in a distorted-tetrahedral O2S2 environment formed by the C=S sulfur atoms and the P=O oxygen atoms of two deprotonated LI ligands. The photoluminescence properties of [ZnLII 2] are also reported.  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