固体酸Fe2(SO4)3催化合成丙酸异戊酯

Solid acid ferric sulphate Fe2(SO4)3 was prepared and used for the study of the catalytic synthesis of iso-amyl propionate. The optimun reaction conditions were follows: the ratio of amount of substance n(iso-amylalcohol) : n(propionic acid) = 1.5, the reaction time 2h, the catalyst quantity 1.5g, and dewatering solvent toluene 10ml. The yield was 97.2% under the optimum reaction conditions. The catalyst being of high catalytic activity for the esterification reactions was prepared very easily and could be used repeatedly.     

低压下碱金属碳酸盐催化一步法合成碳酸二甲酯

报道了低压下碱金属碳酸盐催化环氧化物、CO2和甲醇一步合成碳酸二甲酯(DMC)的方法,系统考察了反应条件对一步合成DMC的影响规律.在最优反应条件下(初始压力0.5 MPa,反应温度120°C,碳酸钠7.5 mol%),以环氧乙烷为起始剂的DMC收率达到63.5%.提出了碱金属碳酸盐催化一步法合成DMC的可能反应机理.     

新型双功能磁性纳米催化剂的制备与表征

传统酸性催化反应以稀硫酸为酸催化剂,虽然稀硫酸的催化活性很高,但由于稀硫酸极易腐蚀设备、不易与反应体系分离、易造成环境污染等缺点,如何用固体超强酸取代稀硫酸作为酸催化剂成为了研究的重点.对目前有关磁性固体超强酸的研究主要有SO42-/ZrO2/MFe2O4(M=Fe,Co,N i)[1~3]和     

Sulfonic acid-functionalized core-shell Fe_3O_4@carbon microspheres as magnetically recyclable solid acid catalysts

Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids.In this work,a series of novel sulfonic acid-functionalized core-shell Fe_3 O_4@carbon microspheres(Fe_3 O_4@C-SO_3 H) have been designed and synthesized as an efficient and recyclable heterogeneous acid catalyst.For the synthesis,core-shell Fe_3 O_4@RF(resorcinol-formaldehyde) microspheres with tunable shell thickness were achieved by interfacial polymerization on magnetic Fe_3 O_4 microspheres.After high-temperature carbonization,the microspheres were eventually treated by surface sulfonation,re sulting in Fe_3 O_4@C-x-SO_3 H(x stands for carbonization temperature) microspheres with abundant surface SO_3 H groups.The obtained microspheres possess uniform core-shell structure,partially-graphitized carbon skeletons,superparamagnetic property,high magnetization saturation value of 10.6 emu/g,and rich SO_3 H groups.The surface acid amounts can be adju sted in the range of 0.59-1.04 mmol/g via sulfonation treatment of carbon shells with different graphitization degrees.The magnetic Fe_3 O_4@C-x-SO_3 H microspheres were utilized as a solid acid catalyst for the acetalization reaction between benzaldehyde and ethylene glycol,demonstrating high selectivity(97%) to benzaldehyde ethylene glycol acetal.More importantly,by applying an external magnetic field,the catalysts can be easily separated from the heterogeneous reaction solutions,which later show well preserved catalytic activity even after 9 cycles,revealing good recyclability and high stability.     

Metal sulfates-catalyzed butanolysis of cellulose: butyl levulinate production and optimization

Direct production of butyl levulinate (BL) by butanolysis of cellulose was carried out using single or combined metal sulfates catalysts. The synergetic enhancement of the ferric sulfate and aluminum sulfate can improve the conversion of cellulose to BL. Moreover, the butanolysis of cellulose was optimized by using response surface methodology. Under the optimum conditions of 194 °C, catalyst concentration 10.0 g/L and reaction time 3 h, the average cellulose conversion of 100% and BL yield of 40.3% were obtained. In addition, the analysis of liquid products and the characterization of catalyst were performed, and the reusability experiments showed that the metal sulfates can be easily recycled and be reused more than five times with high activity in the butanolysis process. This study provided an economical and feasible method for bio-based BL production from cellulose.     

两个线型三核铁(Ⅱ)配合物[Fe3L2(CH3COO)2]的合成和晶体结构

The title linear trinuclear complexes, [Fe₃L₂(CH₃COO)₂](L=bis-(salicylidene)-1,3-diaminopropane (salpd) (1) and L=bis-(salicylidene)-1,4-diaminobutane (salbd) (2) were synthesized simply using solvothermal method in methanol and were characterized by X-ray single crystal diffraction. [Fe₃L₂(CH₃COO)₂](1) was obtained using salicylaldehyde, 1,3-diaminopropane and Fe(CH₃COO)₂·4H₂O via the above method with monoclinic crystal system and space group of P2₁/c, and lattice parameters of a=0.945 0(8) nm, b=1.037 0(8) nm, c=1.830 5(14) nm, β=94.357(16)°. The [Fe₃L₂(CH₃COO)₂](2) was obtained using1,4-diaminobutane instead of 1,3-diaminopropane while keeping the other conditions the same as that for synthesis of [Fe₃L₂(CH₃COO)₂] (1). The [Fe₃L₂(CH₃COO)₂](2) was in monoclinic crystal system and space group of P2₁/c, and lattice parameters of a=0.919 0(5) nm, b=1.675 6(9) nm, c=1.270 0(7) nm, β=95.126(11)°. CCDC: 754930, 1; 754931, 2.     

SO2-tolerant Pt-MoO3/C catalyst for oxygen reduction reaction

A Pt-MoO3/C catalyst,aimed to eliminate the harmful effect of sulfur dioxide（SCb） on the performance of Pt nanoparticles（NPs） for catalysis of oxygen reduction reaction（ORR） in proton exchange membrane fuel cells（PEMFC）,is developed and characterized by TEM,XRD and XPS.The results reveal that Pt-MoO3/C catalyst exhibits not only a higher catalytic activity,but also a better SO2 poisoning resistance and a better recovery performance than the commercial Pt/C catalyst does.     

SO_2-tolerant Pt-MoO_3/C catalyst for oxygen reduction reaction

A Pt-MoO_3/C catalyst,aimed to eliminate the harmful effect of sulfur dioxide(SCb) on the performance of Pt nanoparticles(NPs) for catalysis of oxygen reduction reaction(ORR) in proton exchange membrane fuel cells(PEMFC),is developed and characterized by TEM,XRD and XPS.The results reveal that Pt-MoO_3/C catalyst exhibits not only a higher catalytic activity,but also a better SO_2 poisoning resistance and a better recovery performance than the commercial Pt/C catalyst does.     

Alkylation of Hydroquinone with tert-Butyl Alcohol over Bis[（perfluoroalkyl）sulfonyl]imides Supported on MCM-41

Bis[（perfluoroalkyl）sulfonyl]imides [HN（SO2Rf）2, and Rf represents the perfluorinated alkyl group] supported on MCM-41 were synthesized and characterized by XRD, FTIR, SEM, TGA and N2-adsorption techniques. The supported catalysts, HN（SO2Rf）2/MCM-41, were used as the catalysts for the tert-butylafion of hydroquinone （HQ） with tert-butyl alcohol （TBA） in the liquid phase. A high yield （52.0%） of 2-tert-butyl hydroquinone （TBHQ） could be obtained in the presence of 5 tool% HN（SO2C4F9）2/MCM-41 under the optimized reaction conditions and the heterogeneous catalyst could be recycled at least 6 times without substantial loss of activity.     

银在浸出黄铜矿中的催化作用

本文研究了用Fe_2(SO_4)_3、MnO_2、FeCl_3、CuCl_2等浸出黄铜矿时Ag~ 的作用。Ag~ 在氯化物溶液中不起催化作用。但在酸性Fe_2(SO_4)_3及MnO_2溶液中可使反应速率常数提高200倍,文中导出了在Ag~ 催化作用下硫酸高铁浸出黄铜矿的动力学方程。确定了速率控制步骤是离子通过产物硫层的扩散过程,活化能为35.7kJ/mol。探讨了银催化浸出黄铜矿的反应机理。     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Ce(IV) immobilized on halloysite nanotube–functionalized dendrimer (Ce(IV)–G2): A novel and efficient dendritic catalyst for the synthesis of pyrido[3,2-c]coumarin derivatives

In this study, a new and stable Ce(IV) immobilized on halloysite nanotube–functionalized dendrimer was designed, synthesized, and characterized using Fourier-transform infrared, elemental analysis, thermogravimetric analysis, field emission scanning electron microscopy, scanning electron microscopy–energy dispersive X-ray spectroscopy, transmission electron microscopy, dynamic light scattering, Brunauer–Emmett–Teller, and inductively coupled plasma optical emission spectroscopy techniques. This catalyst was efficiently used for the one-pot, single-step multicomponent synthesis of pyrido[3,2-c]coumarins from 4-aminocoumarin, aldehydes, and aryl ketones. The efficiency and selectivity of this catalytic system were also evaluated for the synthesis of pyrido[3,2-c]coumarins from terminal/internal alkynes instead of aryl ketones. In this respect, the regioselectivity of the products was successfully assigned by X-ray crystallographic analysis. All these reactions were best performed under solvent-free conditions in the presence of only 0.28 mol% of the catalyst, and such a one-pot multicomponent synthesis of pyrido[3,2-c]coumarins is reported for the first time. It is also worth noting that single-step and short reaction path for the synthesis of a variety of pyrido[3,2-c]coumarins along with excellent reusability of this dendritic catalyst makes this method economically and environmentally attractive.     

铁基超细粒子催化剂结构与还原行为的Mssbauer谱研究

铁基超细粒子催化剂具有优良的F-T反应性能。本工作利用原位Mssbauer谱辅以XRD技术研究了含有钾助剂的F-T合成铁基超细粒子催化剂的结构与还原行为,考察了催化剂组成和第二金属组分(Mn,Zn,Mg)的影响。“纯”铁超细粒子催化剂在氢气中很容易经Fe_3O_4还原为零价铁。第二金属组分的引入,一方面阻碍了催化剂的还原,另一方面稳定了Fe~(2+)的存在而使其成为还原的主要中间相,这有利于反应条件下形成类尖晶石结构的活性相。对于Fe-Mn催化剂,上述效应随锰含量的增加而更趋显著。铁基超细粒子催化剂在氢气中的还原能力依“纯”Fe>Fe-Zn>Fe-Mn>Fe-Mg的顺序递减,这在一定程度上反映了铁与第二金属组分之间相互作用的强弱。     

Efficient production of ethyl levulinate from cassava over Al_2(SO_4)_3 catalyst in ethanol–water system

One-pot achievement of ethyl levulinate from cassava was conducted in ethanol-water system over several simple sulfate salt catalysts.Al_2(SO_4)_3 catalyst had the best performance in synthesizing ethyl levulinate comparing with those of a series of sulfate salts.The highest yields of ethyl levulinate was up to39.27%as well as 7.78%levulinate acid when cassava was catalyzed in ethanol medium by adding 10 wt%water.~(13)C and ~1H NMR spectroscopic investigations confirmed that isomerization of glucose to fructose over Al_2(SO_4)_3 catalyst is an important step in producing ethyl levulinate and levulinate acid.Due to aggregations of Al~(3+) under hydrothermal conditions,tiny amount of Al~(3+) were detected in filtrate at the percentage of 0.32%even if in absolute water.Bronsted and Lewis acids could improve the yield of ethyl levulinate and levulinate acid by synergistic effect.All results suggested that A1_2(SO_4)_3 was a simple and efficient catalyst for ethyl levulinate and levulinate acid production.     

簇合物(μ-SC6H5)(μ-P(SC6H5)2)Fe2(CO)6的合成和晶体结构

用Fe_3(CO)_(12)与亚磷酸三硫代苯酯P(SC_6H_5)_3反应得到标题化合物。P(SC_6H_5)_3以其裂解分子片SC_6H_5和P(SC_6H_5)_2配位。用X-ray衍射技术测定了该化合物的晶体结构, 晶体属正交晶系, 空间群为Pbca, a=1.7422(7), b=1.0634(6), c=2.898(12) nm; V=5.370 nm, z=8, D_c=1.579 g·cm~(-3)。由直接法和差值Fourier合成解出全部非氢原子坐标, 并用全矩阵最小二乘法修正, 最后偏离因子R=0.054, R_w=0.058, 分子结构中心的Fe_2SP折叠环沿S…P线或沿Fe—Fe键折叠的二面角(分别为76.1°和82°)比其它具有中心Fe_2S_2, Fe_2P_2和Fe_2SP折叠环的类似化合物中的相应值小, Fe—Fe键长为0.2572 nm, Fe—S(1)—Fe=68.6°, Fe—P—Fe=70.7°。     

钼铁混合金属原子簇化合物[(η5-C5H5)4Mo4Fe2(μ3-S)5(CO)5]的合成和结构

(η~5-C_5H_5)_4Mo_4Fe_2(μ_3-S)_5(CO)_5 have been prepared from (η~5-C_5H_5)_2Mo_2(CO)_6 and Fe_8S_2(CO)_9 under toluene reflux for 14.5 hrs.The crystal and molecular structures of (η~5-C_5H_5)_4Mo_4Fe_2(μ_3-S)_5(CO)_5 were studied by X-ray structure analysis. The Crystallographic data are as follows: monoclinic, space group P2_1/n, unit cell: a=1.0589(4), b=1.7260(4), c=1.8963(4) nm, β=101.44(2)°, V=3.3967 nm, D_c=2.06 gcm~(-3) for Z=4, X-ray data were obtained over the range of 2°<2θ<50° via the ω-2θ scan mode with MoKα radiation on an Enraf-Nonius CAD4 diffractometer. The structure was solved by direct method (MULTAN) and refined by full matrix least-squares techniques for 3993 reflections with I>2σ(I), The final R=0.081. Figure 1 illustrates the configuration of the molecule (η~5-C_5H_5)_4Mo_4Fe_2(μ_3-S)_5(CO)_5, composing of a cubane-like (FeMo_3S_4) core and a trigonal pyramid (MoFe_2S) core, which linked by sharing Fe(1) atom.     

有机高分子与聚合硫酸铁的复配特性

研究了水溶性有机高分子(OP)与聚合硫酸铁(PFS)的复配特点,从分子结构和溶剂化角度探讨了OP在PFS中的稳定机制,并采用FT-IR、SEM和X射线衍射探讨了OP与PFS的相互作用.结果表明:具有吡咯环结构的聚二甲基二烯丙基氯化铵、聚二乙基二烯丙基氯化铵和聚乙烯吡咯烷酮能与PFS复配,且具有较好的稳定性;OP与PFS形成了互相融合的复合体系,主要与PFS中Fe4.67(SO4)6(OH)2.20H2O物相发生相互作用.     

含杂环卡宾碳的铁羰基簇合物的结构化学研究Ⅱ．—Fe_3(CO)_8[:CNHC(S)C(CH_3)_2NH]的合成和晶体结构

Ｆｅ３（ＣＯ）＿（１２）和取代２，４＿二硫代乙内酰脲反应，得到新的取代物Ｆｅ３（ＣＯ）＿８－［：ＣＮＨＣ（Ｓ）Ｃ（ＣＨ＿３）＿２ＮＨ］（μ＿３－Ｓ）＿２，并进行了ＩＲ、１￣ＨＮＭＲ、ＭＳ表征，测定了它的分子和晶体结构，讨论了杂环卡宾碎片：ＣＮＨＣ（Ｓ）Ｃ（ＣＨ＿３）＿２ＮＨ的取代位置，它是通过卡宾碳原子与Ｆｅ配位。     

Cellulose sulfuric acid as a bio-supported and recyclable solid acid catalyst for the synthesis of 5-hydroxymethylfurfural and 5-ethoxymethylfurfural from fructose

In this study, we have developed a new and green method for the synthesis of 5-hydroxymethylfurfural (HMF) and 5-ethoxymethylfurfural (EMF) from fructose using cellulose sulfuric acid as catalyst. Firstly, HMF was synthesized from fructose, and a high yield of 93.6 % was obtained in DMSO for 45 min in the presence of cellulose sulfuric acid. Cellulose sulfuric acid also showed high catalytic activity for the synthesis of EMF. EMF was obtained in a high yield of 84.4 % by the etherification of HMF under the optimal reaction conditions. More importantly, a high EMF yield of 72.5 % was also obtained from fructose through one-pot reaction strategy, which integrated the dehydration of fructose into HMF and the followed etherification of HMF into EMF. The reaction work-up was very simple and the catalyst could be reused several times without the loss of its catalytic activity.