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1.
From the reaction of PtCl2(hex) (hex = hexa‐1,5‐diene) with LiC6F5 in diethyl ether, the complex [Pt{CH(CH2C6F5)CH2CH2CH=CH2}(C6F5)(OH2)] ( 1 ) was isolated. The crystal structure (monoclinic, C2/c (no. 15), Z = 8, a = 15.241(3), b = 16.579(2), c = 16.225(2) Å, β = 111.12(2)°) shows a complex with square planar coordination around platinum with a template formed 1‐pentafluorophenylhex‐5‐en‐2‐yl ligand, and C6F5 and aqua ligands trans to the double bond and alkyl carbon, respectively.  相似文献   

2.
李宁  宗敏华  王菊芳  刘晨  吴虹 《中国化学》2003,21(10):1360-1363
IntroductionOverthepastyears ,thesynthesisofchiralaldehyde cyanohydrinswaswellstudied .1Incontrasttochiralalde hyde cyanohydrins ,therewereonlyfewreportsaboutthepreparationofopticallyactiveketone cyanohydrins ,2 whichareusefulstartingmaterialsandintermediatesforthesyn thesisofmanychiralnaturalproducts .3Wethereforefo cusedonthepreparationofopticallyactivesiliconcontain ing (R ) ketone cyanohydrin ((R ) 2 trimethylsilyl 2 hy droxyl propionitrile)usingacetonecyanohydrinastran scyanationagen…  相似文献   

3.
A thermoregulated phase‐transfer (TRPT) Rh(I) complex catalyst A prepared from Rh(acac)(CO)2 and a thermoregulated ligand CH3(OCH2CH2)mPPh2 (Mw = 918) was applied to the biphasic hydroformylation of 1‐octene, and a high activity with an aldehyde yield of 97.5% was demonstrated. After three recycling steps, the aldehyde yield gradually decreased. Transmission electron microscopy (TEM) revealed that after the first cycle Rh colloids were generated in situ in the aqueous phase, and in subsequent runs Ostwald ripening occurred. An independently prepared colloidal Rh(0) TRPT catalyst D also exhibited high hydroformylation activity under identical experimental conditions, and after two times of recycling an activity decrease was also observed. It is suggested that in situ from Rh(acac)(CO)2 colloidal Rh particles are generated, which demonstrate thermomorphic behaviour and a high hydroformylation activity. Subsequently, agglomeration processes result in an activity decay, as observed in the TRPT Rh(I) complex catalyst system. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

4.
The gas phase reaction kinetics of OH with three di‐amine rocket fuels—N2H4, CH3NHNH2, and (CH3)2NNH2—was studied in a discharge flow tube apparatus and a pulsed photolysis reactor under pseudo‐first‐order conditions in [OH]. Direct laser‐induced fluorescence monitoring of the [OH] temporal profiles in a known excess of the [diamine] yielded the following absolute second‐order OH rate coefficient expressions; k1 = (2.17 ± 0.39) × 10?11 e(160±30)/T, k2 = (4.59 ± 0.83) × 10?11 e(85±35)/T and k3 = (3.35 ± 0.60) × 10?11 e(175±25)/T cm3 molec?1 s?1, respectively, for reactions with N2H4, CH3NHNH2 and (CH3)2NNH2 in the temperature range 232–637 K. All three reactions did not show any discernable pressure dependence on He or N2 buffer gas pressure of up to 530 torr. The magnitude of the weak temperature and the lack of pressure effects of the OH + N2H4 reaction rate coefficient suggest that a simple direct metathesis of H‐atom may not be important compared to addition of the OH to one of the N‐centers of the diamine skeleton, followed by rapid dissociation of the intermediate into products. Our findings on this reaction are qualitatively consistent with a previous ab initio study [ 3 ]. However, in the alkylated diamines, direct H‐abstraction from the methyl moiety cannot be completely ruled out. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 354–362, 2001  相似文献   

5.
李考学  王艳华  蒋景阳  金子林 《催化学报》2010,31(10):1191-1194
 基于温控配体 Ph2P(CH2CH2O)16CH3 稳定的 Rh 纳米催化剂在水/1-丁醇两相体系中具有温控相转移功能, 将其用于高碳烯烃氢甲酰化反应中. 在优化的反应条件下, 1-辛烯转化率和醛收率分别达 98% 和 96%, 对其它高碳烯烃氢甲酰化反应也具有较高的催化性能. 催化剂和产物通过简单的相分离即可分开, 连续使用 3 次后, 催化剂性能未见明显降低.  相似文献   

6.
The organic/aqueous biphasic hydroformylation of 2,5‐norbornadiene (NBD) was investigated for the first time using HRh(CO)(TPPTS)3 (TPPTS: trisodium salt of tri(m‐sulphonylphenyl)phosphine) as the catalyst precursor. A comparison was made of homogeneous and biphasic systems. The optimum reaction parameters are discussed and the reaction mechanism is presented. In order to ensure the process attained high activity under moderate conditions, the effect of various cationic surfactants was tested in the biphasic hydroformylation of NBD. The results indicated that the hydroformylation of NBD in the biphasic system exhibited high activity and high selectivity to dialdehyde products under mild conditions. The addition of cationic surfactants markedly accelerated the reaction. A single long‐chain surfactant seemed to exert a greater impact on the hydroformylation of NBD than a double long‐chain surfactant. Moreover, the recycling of aqueous solution containing catalyst with or without surfactant was investigated. In the absence of the surfactant, the aqueous catalyst could be recycled six times without a significant decrease in activity and selectivity. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

7.
Pulse radiolysis techniques were used to measure the gas phase UV absorption spectra of the title peroxy radicals over the range 215–340 nm. By scaling to σ(CH3O2)240 nm = (4.24 ± 0.27) × 10?18, the following absorption cross sections were determined: σ(HO2)240 nm = 1.29 ± 0.16, σ(C2H5O2)240 nm = 4.71 ± 0.45, σ(CH3C(O)CH2O2)240 nm = 2.03 ± 0.22, σ(CH3C(O)CH2O2)230 nm = 2.94 ± 0.29, and σ(CH3C(O)CH2O2)310 nm = 1.31 ± 0.15 (base e, units of 10?18 cm2 molecule?1). To support the UV measurements, FTIR‐smog chamber techniques were employed to investigate the reaction of F and Cl atoms with acetone. The F atom reaction proceeds via two channels: the major channel (92% ± 3%) gives CH3C(O)CH2 radicals and HF, while the minor channel (8% ± 1%) gives CH3 radicals and CH3C(O)F. The majority (>97%) of the Cl atom reaction proceeds via H atom abstraction to give CH3C(O)CH2 radicals. The results are discussed with respect to the literature data concerning the UV absorption spectra of CH3C(O)CH2O2 and other peroxy radicals. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 283–291, 2002  相似文献   

8.
Germatranes bearing a ferrocenylalkoxyl moiety have been obtained by the reaction of HOGe(OCH2CH2)3N with various ferrocenyl alcohols. A convenient new synthesis method of FcCH2OGe(OCH2CH2)3N was reported. FcCH2OGe(OCH2CH2)3N was prepared in 93% yield when FcCH2OH reacted with HOGe(OCH2CH2)3N in chloroform at room temperature in the presence of molecular sieves (3 Å) as a dehydrating agent. All compounds were characterized by elemental analysis, 1H NMR and IR spectroscopy. The molecular structures of FcCH2OGe(OCH2CH2)3N and FcCH(CH3)OGe(OCH2CH2)3N have been determined by X‐ray diffraction. The antitumor activities of FcCH2OGe(OCH2CH2)3N and p‐FcC6H4CH2OGe(OCH2CH2)3N were determined. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

9.
Synthesis and Crystal Structure of the Heterobimetallic Diorganotindichloride (FcN, N)2SnCl2 (FcN, N: (η5‐C5H5)Fe{η5‐C5H3[CH(CH3)N(CH3)CH2CH2NMe2]‐2}) The heterobimetallic title compound [(FcN, N)2SnCl2] ( 1 ) was obtained by the reaction of [LiFcN, N] with SnCl4 in the molar ratio 1:1 in diethylether as a solvent. The two FcN, N ligands in 1 are bound to Sn through a C‐Sn σ‐bond; the amino N atoms of the side‐chain in FcN, N remain uncoordinated. The crystals contain monomeric molecules with a pseudo‐tetrahedral coordination at the Sn atom: Space group P21/c; Z = 4, lattice dimensions at —90 °C: a = 9.6425(2), b = 21.7974(6), c = 18.4365(4) Å, β = 100.809(2)°, R1obs· = 0.051, wR2obs· = 0.136.  相似文献   

10.
《中国化学会会志》2018,65(5):505-510
A facile and efficient protocol has been developed for synthesis of 1,4‐disubstituted 1,2,3‐triazoles in good to excellent yields using Cu(OAc)2·H2O (0.5 mol%)/NH2OH·HCl (0.5 mol%)/CH3COONa (1.0 mol%) as the catalyst system. The presence of CH3COONa (2 equiv) could ensure the in situ generation of Cu2O as the active catalyst instead of CuCl from Cu(OAc)2·H2O (1 equiv)/NH2OH·HCl (1 equiv). This protocol could be carried out in water under mild conditions.  相似文献   

11.
A study of the reaction initiated by the thermal decomposition of di-t-butyl peroxide (DTBP) in the presence of (CH3)2C?CH2 (B) at 391–444 K has yielded kinetic data on a number of reactions involving CH3 (M·), (CH3)2CCH2CH3 (MB·) and (CH3)2?CH2C(CH3)2CH2CH3 (MBB·) radicals. The cross-combination ratio for M· and MB· radicals, rate constants for the addition to B of M· and MB· radicals relative to those for their recombination reactions, and rate constants for the decomposition of DTBP, have been determined. The values are, respectively, where θ = RT ln 10 and the units are dm3/2 mol?1/2 s?1/2 for k2/k and k9/k, s?1 for k0, and kJ mol?1 for E. Various disproportionation-combination ratios involving M·, MB·, and MBB· radicals have been evaluated. The values obtained are: Δ1(M·, MB·) = 0.79 ± 0.35, Δ1(MB·, MB·) = 3.0 ± 1.0, Δ1(MBB·, MB·) = 0.7 ± 0.4, Δ1(M·, MBB·) = 4.1 ± 1.0, Δ1(MB·, MBB·) = 6.2 ± 1.4, and Δ1(MBB·, MBB·) = 3.9 ± 2.3, where Δ1 refers to H-abstraction from the CH3 group adjacent to the center of the second radical, yielding a 1-olefin. © 1994 John Wiley & Sons, Inc.  相似文献   

12.
Pulse radiolysis was used to study the kinetics of the reactions of CH3C(O)CH2O2 radicals with NO and NO2 at 295 K. By monitoring the rate of formation and decay of NO2 using its absorption at 400 and 450 nm the rate constants k(CH3C(O)CH2O2+NO)=(8±2)×10−12 and k(CH3C(O)CH2O2+NO2)=(6.4±0.6)×10−12 cm3 molecule−1 s−1 were determined. Long path length Fourier transform infrared spectrometers were used to investigate the IR spectrum and thermal stability of the peroxynitrate, CH3C(O)CH2O2NO2. A value of k−6≈3 s−1 was determined for the rate of thermal decomposition of CH3C(O)CH2O2NO2 in 700 torr total pressure of O2 diluent at 295 K. When combined with lower temperature studies (250–275 K) a decomposition rate of k−6=1.9×1016 exp (−10830/T) s−1 is determined. Density functional theory was used to calculate the IR spectrum of CH3C(O)CH2O2NO2. Finally, the rate constants for reactions of the CH3C(O)CH2 radical with NO and NO2 were determined to be k(CH3C(O)CH2+NO)=(2.6±0.3)×10−11 and k(CH3C(O)CH2+NO2)=(1.6±0.4)×10−11 cm3 molecule−1 s−1. The results are discussed in the context of the atmospheric chemistry of acetone and the long range atmospheric transport of NOx. © John Wiley & Sons, Inc. Int J Chem Kinet: 30: 475–489, 1998  相似文献   

13.
The fast flow method with laser induced fluorescence detection of CH3C(O)CH2 was employed to obtain the rate constant of k1 (298 K) = (1.83 ± 0.12 (1σ)) × 1010 cm3 mol?1 s?1 for the reaction CH3C(O)CH2 + HBr ? CH3C(O)CH3 + Br (1, ?1). The observed reduced reactivity compared with n‐alkyl or alkoxyl radicals can be attributed to the partial resonance stabilization of the acetonyl radical. An application of k1 in a third law estimation provides ΔfH(CH3C(O)CH2) values of ?24 kJ mol?1 and ?28 kJ mol?1 depending on the rate constants available for reaction ( ‐1 ) from the literature. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 38: 32–37, 2006  相似文献   

14.
A hydrothermal reaction of a mixture of ZnO, HCl, ethylenediphosphonic acid, ethylenediamine, acetic acid in a water, THF mixture gave rise to a new three‐dimensional zinc ethylenediphosphonate, [NH3(CH2)2NH3][Zn3{O3P(CH2)2}4], I . The structure, determined by single crystal X‐ray diffraction, (monoclinic, space group = C2/c, a = 16.9948(14), b = 6.7383(6), c = 16.8886(14)Å, β = 1113.568(1)°, V = 1772.7(3)Å3, Z = 4, R1 = 0.0227, wR2 = 0.0601), consists of a network of strictly alternating ZnO4 and PO3C tetrahedral units linked through their vertices forming the three‐dimensional structure. The amine molecules occupy the middle of the 8‐membered channels and interact with the framework through the hydrogen bonds. Unlike other zinc diphosphonates, I appear to have close similarity to zinc phosphate structures reported in the literature. To our knowledge, this is the first three‐dimensional zinc diphosphonate prepared in the presence of an organic amine molecule.  相似文献   

15.
The rate constant of the title reaction is determined during thermal decomposition of di-n-pentyl peroxide C5H11O( )OC5H11 in oxygen over the temperature range 463–523 K. The pyrolysis of di-n-pentyl peroxide in O2/N2 mixtures is studied at atmospheric pressure in passivated quartz vessels. The reaction products are sampled through a micro-probe, collected on a liquid-nitrogen trap and solubilized in liquid acetonitrile. Analysis of the main compound, peroxide C5H10O3, was carried out by GC/MS, GC/MS/MS [electron impact EI and NH3 chemical ionization CI conditions]. After micro-preparative GC separation of this peroxide, the structure of two cyclic isomers (3S*,6S*)3α-hydroxy-6-methyl-1,2-dioxane and (3R*,6S*)3α-hydroxy-6-methyl-1,2-dioxane was determined from 1H NMR spectra. The hydroperoxy-pentanal OHC( )(CH2)2( )CH(OOH)( )CH3 is formed in the gas phase and is in equilibrium with these two cyclic epimers, which are predominant in the liquid phase at room temperature. This peroxide is produced by successive reactions of the n-pentoxy radical: a first one generates the CH3C·H(CH2)3OH radical which reacts with O2 to form CH3CH(OO·)(CH2)3OH; this hydroxyperoxy radical isomerizes and forms the hydroperoxy HOC·H(CH2)2CH(OOH)CH3 radical. This last species leads to the pentanal-hydroperoxide (also called oxo-hydroperoxide, or carbonyl-hydroperoxide, or hydroperoxypentanal), by the reaction HOC·H(CH2)2CH(OOH)CH3+O2→O()CH(CH2)2CH(OOH)CH3+HO2. The isomerization rate constant HOCH2CH2CH2CH(OO·)CH3→HOC·HCH2CH2CH(OOH)CH3 (k3) has been determined by comparison to the competing well-known reaction RO2+NO→RO+NO2 (k7). By adding small amounts of NO (0–1.6×1015 molecules cm−3) to the di-n-pentyl peroxide/O2/N2 mixtures, the pentanal-hydroperoxide concentration was decreased, due to the consumption of RO2 radicals by reaction (7). The pentanal-hydroperoxide concentration was measured vs. NO concentration at ten temperatures (463–523 K). The isomerization rate constant involving the H atoms of the CH2( )OH group was deduced: or per H atom: The comparison of this rate constant to thermokinetics estimations leads to the conclusion that the strain energy barrier of a seven-member ring transition state is low and near that of a six-member ring. Intramolecular hydroperoxy isomerization reactions produce carbonyl-hydroperoxides which (through atmospheric decomposition) increase concentration of radicals and consequently increase atmospheric pollution, especially tropospheric ozone, during summer anticyclonic periods. Therefore, hydrocarbons used in summer should contain only short chains (<C4) hydrocarbons or totally branched hydrocarbons, for which isomerization reactions are unlikely. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet 30: 875–887, 1998  相似文献   

16.
The gas‐phase kinetics of CHBr2 + NO2 and CH3CHBr + NO2 reactions have been studied in direct time resolved measurements using a tubular flow reactor coupled to a photoionization mass spectrometer. The radicals were generated by pulsed laser photolysis of bromoform and 1,1‐dibromoethane at 248 nm. The subsequent decays of the radical concentrations were monitored as a function of [NO2] under pseudo–first‐order conditions. The rate coefficients of both reactions are independent of bath gas (He) pressure and display negative temperature dependence under the conditions of 2–6 Torr pressure (He) and 250–480 K. The obtained bimolecular rate coefficients are k(CHBr2 + NO2) = (9.8 ± 0.4) × 10?12 (T/300 K)?1.65 ± 0.18 cm3 s?1 (288–483 K) and k(CH3CHBr + NO2) = (2.27 ± 0.06) × 10?11 (T/300 K)?1.28 ± 0.11 cm3 s?1 (250–483 K), with the uncertainties given as one standard error. Estimated overall uncertainties in the measured bimolecular reaction rate coefficients are ±25%. The reaction products identified were CBr2O for the CHBr2 + NO2 reaction and CHBrO and CH3CHO with minor amounts of CH3 for the CH3CHBr + NO2 reaction, respectively. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 767–777, 2012  相似文献   

17.
Summary Diphenylacetylene and 1-phenyl-1-propyne were hydrogenated to the corresponding 1,2-disubstituted alkenes in aqueous organic biphasic media using the water-soluble catalyst [{RuCl2(mtppms)2}2] and an excess of the sulfonated phosphine ligand. The stereoselectivity of the reaction strongly depends on the pH of the catalyst-containing aqueous phase and under acidic conditions Z-alkenes can be obtained with a selectivity close to 100%.  相似文献   

18.
The UV absorption spectrum and kinetics of CH2I and CH2IO2 radicals have been studied in the gasphase at 295 K using a pulse radiolysis UV absorption spectroscopic technique. UV absorption spectra of CH2I and CH2IO2 radicals were quantified in the range 220–400 nm. The spectrum of CH2I has absorption maxima at 280 nm and 337.5 nm. The absorption cross-section for the CH2I radicals at 337.5 nm was (4.1 ± 0.9) × 10?18 cm2 molecule?1. The UV spectrum of CH2IO2 radicals is broad. The absorption cross-section at 370 nm was (2.1 ± 0.5) × 10?18 cm2 molecule?1. The rate constant for the self reaction of CH2I radicals, k = 4 × 10?11 cm3 molecule?1 s?1 at 1000 mbar total pressure of SF6, was derived by kinetic modelling of experimental absorbance transients. The observed self-reaction rate constant for CH2IO2 radicals was estimated also by modelling to k = 9 × 10?11 cm3 molecule?1 s?1. As part of this work a rate constant of (2.0 ± 0.3) × 10?10 cm3 molecule?1 s?1 was measured for the reaction of F atoms with CH3I. The branching ratios of this reaction for abstraction of an I atom and a H atom were determined to (64 ± 6)% and (36 ± 6)%, respectively. © 1994 John Wiley & Sons, Inc.  相似文献   

19.
两种镍的配合物[Ni(NH2CH2CH2CH2NH2)3]Cl2 (1)和[Ni(C6H4N2H4)2Cl2] (2)已经被合成并且通过红外和单晶X射线衍射分析对其进行了表征。在配合物1中,镍原子处于手性假八面体[NiN6]的几何构型中,它与三个1,3-丙二胺分子形成了三个六元环。在配合物2中,镍原子除了与两个o-苯二胺分子通过四个Ni-N键形成两个五元环外,它还与两个Cl原子配位形成了反式Ni-Cl2,这不同于以往报道过的镍的二胺配合物。这两个镍的配合物被MAO, MMAO或Et2AlCl活化后,对乙烯的二聚合或三聚合显示了很好的催化活性[对于配合物2,催化活性达到3.59×106 g mol-1 (Ni) h-1]。  相似文献   

20.
Two mixed‐valent disc‐like hepta‐nuclear compounds of [FeIIFeIII6(tea)6](ClO4)2 ( 1Fe , tea = N(CH2CH2O)33?) and [MnII3MnIII4(nmdea)6(N3)6]·CH3OH ( 2Mn , nmdea = CH3N(CH2CH2O)22?) have been synthesized by the reaction of Fe(ClO4)2·6H2O with triethanolamine (H3tea) for the former and reaction of Mn(ClO4)2·6H2O with diethanolamine (H2nmdea) and NaN3 for the later, respectively. 1Fe has the cationic cluster with a planar [FeIIFeIII6] core consisting of one central FeII and six rim FeIII atoms in hexagonal arrangement. The Fe ions are linked by the oxo‐bridges from the alcohol arms in the manner of edge‐sharing of their coordination octahedra. 2Mn is a neutral cluster with a [MnII3MnIII4] core possessing one central MnII atom surrounded by six rim Mn ions, two MnII and four MnIII. The structure is similar to 1Fe but involves six terminal azido ligands, each coordinate one rim Mn ion. 1Fe showed dominant antiferromagnetic interaction within the cluster and long‐range ordering at 2.7 K. The cluster probably has a ground state of low spin of S = 5/2 or 4/2. The long‐range ordering is weak ferromagnetic, showing small hysteresis with a remnant magnetization of 0.3 Nβ and a coercive field of 40 Oe. Moreover, the isofield of lines 1Fe are far from superposition, indicating the presence of significant zero–field splitting. Ferromagnetic interactions are dominant in 2Mn . An intermediate spin ground state 25/2 is observed at low field. In high field of 50 kOe, the energetically lowest state is given by the ms = 31/2 component of the S = 31/2 multiplet due to the Zeeman effect. Despite of the large ground state, no single‐molecule magnet behavior was found above 2 K.  相似文献   

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