摘要:

AbstractThe photochemical vibrational reaction of UF6+HCl was investigated by exciting the ternary overtone of 3V3of UF6in an intracavity CO laser system. It was found that the rate of the laser‐driven reaction was much greater than that of the thermal reaction and this photochemical process had an isotopic selectivity. The uranium isotope enrichment factors measured in experiments were around 1,007 in a single ste

ISSN:1001-604X    

DOI:10.1002/cjoc.19930110201

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA, Weinheim    

年代:1993

数据来源: WILEY

摘要:

AbstractThree series of dealuminated Y zeolites have been prepared by chemical extraction of hydrothermally dealuminated Y zeolite (USY) with H2Na2EDTA, HCl and H4EDTA. The unit cell constant, mesopore distribution, acidity and extraframework aluminum (EFAL) of the zeolites were studied with XRD, chemical analyses, adsorption, IR and NH3‐TPD techniques. It was shown that H2Na2EDTA only removed EFAL species deposited in the pores of USY, by contrast, HCl and H4EDTA extract both extraframework and framework aluminum, and make the zeolite framework further dealuminated. Adsorption tests gave evidence that a secondary pore system exists in these dealuminated zeolites. H2Na2EDTA extraction increased both micropore and mesopore volumes, but after HCl and H4EDTA treatments, new mesopores formed and the micropore volume was decreased. The pyridine‐IR and NH3‐TPD measurements demonstrated that EFAL had no evident contribution to the zeolite ac

ISSN:1001-604X    

DOI:10.1002/cjoc.19930110202

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA, Weinheim    

年代:1993

数据来源: WILEY

摘要:

AbstractThe calculated TST‐CEQ state‐selected reaction cross sections and rate constants for the exchange reaction of H+ClH are reported. It is found that, although the collinear probabilities exhibit the oscillating behaviour, the TST‐CEQ cross sections do not oscillate. Comparison of the different state‐selected cross sections at a constant total energy indicates that translational energy is more effective than vibrational energy in promoting the reaction H + ClH. We also find that, the larger the vibrational quantum number of the reactant, the larger the reactive rate constantkTST‐CEQ(T, v) is at a given temperature. The state‐selected rate constants are then averaged to yield the thermal rate constants which are shown to be in good agreement with our VTST calculations and those by Sch

ISSN:1001-604X    

DOI:10.1002/cjoc.19930110203

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA, Weinheim    

年代:1993

数据来源: WILEY

摘要:

AbstractA series of functional surfactants ofN‐alkyl‐N′‐butyl viologens has been synthesized. The quenching of excited singlet and triplet states of zinc phthalocyanine was studied in DMSO and in mixed micelles containing the functional surfactant as one and cationic cetyl trimethylammonium bromide (CTAB), anionic sodium dodecylsulfate (SDS) and neutral TX‐100 surfactant as the other component. Fluorescence quenching and laser photolysis studies indicate that the functional surfactants are solubilized at different sites in micelles, the process depends on chain length and exerts great influence on the quenching of zinc phthalocyanine excit

ISSN:1001-604X    

DOI:10.1002/cjoc.19930110204

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA, Weinheim    

年代:1993

数据来源: WILEY

摘要:

AbstractReactions of [NH4]2[MS4] (M = Mo, W), AgX (X = Cl, Br, I, ON, SCN) and PPh3in the solid state produced six new mixed‐metal sulfur containing cluster compounds, two of which, {Ag3MoS3I}(PPh3)3S(1) and {Ag3WS3Cl}(PPh3)3S·0.5P(S)Ph3·3H2O(2), were determined by single crystal X‐ray analysis. The crystal data: 1, triclinic,P&1bar;,a=12.114(2),b=13.420(2),c=20.346(3)Å,a=74.53(1), βequals;86.73(1), γequals;63.74(1)*,Z=2,R= 0.043 for 4805 independent data, 2, hexagonal,R3,a=b=16.201(3),c=45.091(10)Å,Z=6,R= 0.042 for 2729 independent data. The central unit {Ag3MS3X} (M = Mo, W; X = Cl, I) of the two compounds can be described as a slightly distorted cube, four corners being formed by the MS42−ligand (with a terminal S atom). The remaining corners are occupied by one X (Cl or I) atom and three Ag atoms (with one PPh3ligand bound to each of the latter). The generation of different types of Ag‐Mo(W)‐S cluster compounds prepared from solid state reactions under different reaction temperatur

ISSN:1001-604X    

DOI:10.1002/cjoc.19930110205

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA, Weinheim    

年代:1993

数据来源: WILEY

摘要:

AbstractComplex (n‐Bu4N)[Mo2O2(OMe)(mp)3] [1, mp = (o‐OC6H4S)2−] was synthesized by the reaction of MoOCl3(THF)2and Na2mp in EtOH and crystallized in monoclinic space groupP21/nwith crystal data:a= 13.910(3),b= 23.554(3),c=12.558(2) Å, β = 105.20(2)˙.Z= 4,Do= 1.455g/ cm3, finalR= 0.077 for 5325 reflections [I>3s̀(I)]. The two [Mo(O)mp]+ moieties are bridged by one 1,2‐bidentate ligand mp2−with exceedingly small bite angle (69.0˙) and bite distance · (2.70Å) and by a methoxy group. The structure can be interpreted as two distorted octahedra around the Mo atoms sharing a face. Attempts have been made to provide structural informations for the syntheses of modelling compounds of FeMoco by comparing the Mo—O and Mo—S bond distances ofo‐mercaptophenolate ligated compounds to those of the molybden

ISSN:1001-604X    

DOI:10.1002/cjoc.19930110206

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA, Weinheim    

年代:1993

数据来源: WILEY

摘要:

AbstractThe compound (n‐Bu4N)2[W2Cu4S8(S2CNC4H8)2] was obtained by the reaction of Bu4NBr, (NH4)2WS4, NaS2NCC4H8and CuCl in CH3CN and CH3OH. It crystallizes in the monoclinic space group P21/cwith unit cell parameters:a=21.875(5),b=16.843(4),c=17.745(5)Å, β = 101.69(6)°,V=6402(6)Å3,Z=4,Dc=1.718 g·cm−3. The finalRandRwvalues converged to 0.055 and 0.060 respectively. The structure consists of two ‘butterfly’ units [WS4Cu2] linked together by two weak Cu—S bonds and two bridging S2CNC4H8ligands. Infrared spectra gave characteristic absorptions at 495 cm−1for W=S and 450, 435, 4

ISSN:1001-604X    

DOI:10.1002/cjoc.19930110207

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA, Weinheim    

年代:1993

数据来源: WILEY

摘要:

AbstractSodium nitrosylcarbonyliron reacts with methylcyclopentadienylcarbonylmetal (Mo or W) chloride in CH3OH/THF at room temperature to give Cp*Mo(CO)2NO(la) (Cp* = η5−CH3C5H4) or Cp*W(CO)2NO (1b), [Cp*Mo(CO)3]2(2a) or [Cp*W(CO)3]2(2b), and Cp*Mo(μ3‐NH)(μ2‐NO)‐(μ2‐CO)Fe2(CO)6(3a) or Cp*W(μ3‐NH)(μ2‐NO)(μ2‐CO)Fe2(CO)6(3b), respectively. Complexes 1a, 1b, 3a and 3b were analyzed by IB, NMR, MS and elemental analyses, and the crystal structures of 1b, 3a and 3b were determined by X‐ray diffraction method. The new clusters 3a and 3b have μ3‐NH ligands which were formed by reduction of NO

ISSN:1001-604X    

DOI:10.1002/cjoc.19930110208

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA, Weinheim    

年代:1993

数据来源: WILEY

摘要:

AbstractThe title compound, sarcophytol‐A benzyl ether has been synthesized through 13 steps by employing acetone and geraniol as starting materials. The key steps in the synthesis were double bond migration reaction of allylic alcohols 5 and 6, phase transfer catalytic coupling (PTC) reaction of II with 7 and the cyclization reaction of dicarbonyl acyclic precursor induced by TiCl3‐AlCl3(3:1)/Zn‐Cu s

ISSN:1001-604X    

DOI:10.1002/cjoc.19930110209

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA, Weinheim    

年代:1993

数据来源: WILEY

摘要:

AbstractLinalyl alkyl or aryl carbinols were regioselectively synthesized by the reaction of geranyl bromide and powdered tin with aldehydes and ketones.

ISSN:1001-604X    

DOI:10.1002/cjoc.19930110210

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA, Weinheim    

年代:1993

数据来源: WILEY