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以NaHSO4*H2O催化苯甲酸与甲醇的酯化反应,合成了苯甲酸甲酯.研究结果表明,NaHSO4*H2O具有较高的催化活性.考察了苯甲酸/甲醇摩尔比、催化剂用量及反应时间对酯产率的影响.在优化反应条件[n(苯甲酸)∶n(甲醇)∶n(NaHSO4*H2O)=1∶2∶0.29,回流8h]下,苯甲酸甲酯产率达85.3%. 相似文献
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以La2O3/TiOSO4催化合成油酸月桂酯,酯化率在96%以上。优化反应条件为:油酸100 mmol,n(月桂醇)∶n(油酸)=1.1∶1.0,w(La2O3/TiOSO4)=2%,甲苯15 mL,回流反应1.5 h。 相似文献
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甲烷磺酸铜的合成及在催化酯化反应中的性能研究 总被引:6,自引:1,他引:5
合成了甲烷磺酸铜 ,其结构经热重分析和IR表征。研究了以其催化乙酸与异戊醇酯化反应的性能及各种因素对酯化率的影响。反应条件为 :乙酸 1 67mmol,n(乙酸 )∶n(异戊醇 ) =1 .0∶1 .1 ,催化剂用量 0 .2 5 % (以酸的摩尔数计 ) ,回流反应 2 .0h ,不加带水剂 ,酯化率可达 96.0 %。其催化活性远远高于CuSO4·5H2 O ,CuCl2 ·2H2 O ,Cu(NO3 ) 2 ·3H2 O ,Cu(CH3 CO2 ) 2 ·H2 O及其它Lewis酸催化剂 ,而且反应过程中不水解 ,反应后经过简单的相分离即可重复使用 ,并成功地用于催化合成其它酯。 相似文献
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固体酸ZrO2-Ce2O3/SO2-4催化合成丙二酸二丁酯 总被引:2,自引:0,他引:2
以含铈固体超强酸ZrO2-Ce2O3/SO4 2-为催化剂,丙二酸和正丁醇为原料合成了丙二酸二丁酯.最佳反应条件为:催化剂活化温度500℃,丙二酸100mmol,n(酸):n(醇)=1.0:2.5,催化剂用量1g,反应时间2h,酯化率达95.8%.结果表明,加入铈有助于提高固体超强酸的使用寿命. 相似文献
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Martin Sahlberg Yvonne Andersson 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(3):i7-i8
Scandium magnesium gallide, Sc2MgGa2, and yttrium magnesium gallide, Y2MgGa2, were synthesized from the corresponding elements by heating under an argon atmosphere in an induction furnace. These intermetallic compounds crystallize in the tetragonal Mo2FeB2‐type structure. All three crystallographically unique atoms occupy special positions and the site symmetries of (Sc/Y, Ga) and Mg are m2m and 4/m, respectively. The coordinations around Sc/Y, Mg and Ga are pentagonal (Sc/Y), tetragonal (Mg) and triangular (Ga) prisms, with four (Mg) or three (Ga) additional capping atoms leading to the coordination numbers [10], [8+4] and [6+3], respectively. The crystal structure of Sc2MgGa2 was determined from single‐crystal diffraction intensities and the isostructural Y2MgGa2 was identified from powder diffraction data. 相似文献
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Paul-Louis Fabre Dominique de Montauzon René Poilblanc 《Transition Metal Chemistry》1987,12(5):434-440
Summary The ability of [MoS4]2–, anions to be used as ligands for transition metal ions has been widely demonstrated, especially with Fe2+. The present study has been restricted to linear complexes such as (NEt4)2 [Cl2FeS2MoS2] and (NEt4)2[Cl2FeS2MoS2FeCl2]. Their electrochemical properties are described: upon electrochemical reduction, these compounds yield MoS2, as a black precipitate, and an iron complex in solution, assumed to be [SFeCl2]2–. The electrochemical reduction goes through two electron transfers, coupled with the breakdown of the molecular skeleton: a DISPl and an ECE mechanism. Depending on the solvent, the following equilibrium may be observed: [Cl4Fe2MoS4]2–[Cl2FeMoS4]2–+FeCl2. The equilibrium constant, KD, was evaluated by differential pulse polarography. KD is tightly related to the donor number of the solvent. 相似文献
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Marina I. Naumova Natalia V. Kuratieva Nina V. Podberezskaya Dmitry Yu. Naumov 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(5):i53-i55
The structures of the hypophosphites KH2PO2 (potassium hypophosphite), RbH2PO2 (rubidium hypophosphite) and CsH2PO2 (caesium hypophosphite) have been determined by single‐crystal X‐ray diffraction. The structures consist of layers of alkali cations and hypophosphite anions, with the latter bridging four cations within the same layer. The Rb and Cs hypophosphites are isomorphous. 相似文献
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On Dialkali Metal Dichalcogenides β-Na2S2, K2S2, α-Rb2S2, β-Rb2S2, K2Se2, Rb2Se2, α-K2Te2, β-K2Te2 and Rb2Te2 The first presentation of pure samples of α- and β-Rb2S2, α- and β-K2Te2, and Rb2Te2 is described. Using single crystals of K2S2 and K2Se2, received by ammonothermal synthesis, the structure of the Na2O2 type and by using single crystals of β-Na2S2 and β-K2Te2 the Li2O2 type structure will be refined. By combined investigations with temperature-dependent Guinier-, neutron diffraction-, thermal analysis, and Raman-spectroscopy the nature of the monotropic phase transition from the Na2O2 type to the Li2O2 type will be explained by means of the examples α-/β-Na2S2 and α-/β-K2Te2. A further case of dimorphic condition as well as the monotropic phase transition of α- and β-Rb2S2 is presented. The existing areas of the structure fields of the dialkali metal dichalcogenides are limited by the model of the polar covalence. 相似文献
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[reaction: see text] Fluoranthene 2 and heptacycle 3 are easily accessible from the reaction of diyne 1 and norbornadiene (NBD) in the presence of the rhodium catalyst. The unusual [(2+2)+(2+2)] adduct 3 was confirmed by the X-ray crystal structure analysis. 相似文献
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[(n‐Bu)2Sn(O2PPh2)2] ( 1 ), and [Ph2Sn(O2PPh2)2] ( 2 ) have been synthesized by the reactions of R2SnCl2 (R=n‐Bu, Ph) with HO2PPh2 in Methanol. From the reaction of Ph2SnCl2 with diphenylphosphinic acid a third product [PhClSn(O2PPh2)OMe]2 ( 3 ) could be isolated. X‐ray diffraction studies show 1 to crystallize in the monoclinic space group P21/c with a = 1303.7(1) pm, b = 2286.9(2) pm, c = 1063.1(1) pm, β = 94.383(6)°, and Z = 4. 2 crystallizes triclinic in the space group , the cell parameters being a = 1293.2(2) pm, b = 1478.5(4) pm, c = 1507.2(3) pm, α = 98.86(3)°, β = 109.63(2)°, γ = 114.88(2)°, and Z = 2. Both compounds form arrays of eight‐membered rings (SnOPO)2 linked at the tin atoms to form chains of infinite length. The dimer 3 consists of a like ring, in which the tin atoms are bridged by methoxo groups. It crystallizes triclinic in space group with a = 946.4(1) pm, b = 963.7(1) pm, c = 1174.2(1) pm, α = 82.495(6)°, β = 66.451(6)°, γ = 74.922(6)°, and Z = 1 for the dimer. The Raman spectra of 2 and 3 are given and discussed. 相似文献
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Photoionization Mass Spectra of SCl2, S2Cl2, and S2Br2 Photoionization mass spectra of SCl2, S2Cl2, and S2Br2 have been measured. Heats of formation, bond energies, and ionization potentials of fragments have been calculated from appearance potentials. 相似文献