Metathesis of Butylene-2 and Ethylene to Propylene over 3.0Mo/(Hβ+γ-Al_2O_3) Catalysts with Different γ-Al_2O_3 Contents

A series of 3.0Mo/(Hβ+γ-Al_2O_3) samples with γ-Al_2O_3 contents in the range of 0_100%(mass fraction) was studied by means of XRD, NH_3-TPD, TPR and BET determinations for characterizing their structures. The Hβ zeolite structure in the 3.0Mo/Hβ sample can be effectively stabilized by adding some γ-Al_2O_3 to Hβ zeolite. γ-Al_2O_3 mainly favors the formation of polymolybdate or multilayered Mo oxide, while Hβ mainly forms the Al_2(MoO_4)_3 species, as evaluated by the TPR technique. When used as the catalyst for the metathesis of butylene-2 and ethylene to propylene, there exists a close correlation between the specific surface area and stability of the catalyst. The specific surface area of the catalyst shows the maximum when {(Hβ+}γ-Al_2O_3) contains 30%γ-Al_2O_3, which is in agreement with that of the time needed for the reaction stablization. In the case of maximum surface area, the rate of coke deposition is the minimum.

Characterization ofanovel deep-seamicrobial esterase EstC 10 and its use in the generation o f(R)-methyl 2-chloropropionate

A novel esterase EstC10 from Bacillus sp. CX01 isolated from the deep sea of the Western Pacific Ocean and the functionalities of EstC 10 was characterized. At present, the reports about the kinetic resolution ofracemic methyl 2-chloropropionate were quite rare. So we developed deep-sea microbial esterase EstC10 as a novel biocatalyst in the kinetic resolution of racemic methyl 2-chloropropionate and generate （R）-methyl 2-chloropropionate with high enantiomeric excess （〉99%） after the optimization of process parameters such as pH, temperature, organic co-solvents, surfactants, substrate concentration and reaction time. Notably, the optimal substrate concentration （80 mmol/L） of esterase EstC10 was higher than the kinetic resolution of another esterase, Estl2-7 （50 mmoFL）. The novel microbial esterase EstC10 identified from the deep sea was a promising green biocatalyst in the generation of （R）-methyl 2-chloropropionate as well of many other valuable chiral chemicals in industry.

Controlled Self-assembly of Two Coordination Polymers via subtly Varying Bis(2-methyl imidazole) Ligands:from 3-Connected(6,3) Net to 4-Connected sql Net

Two coordination polymers constructed from 3,4-thiophenedicarboxylic acid and bis（2-methyl imidazole） ligands, namely, {[Cd2（tdc）2（bip）2]·7H20}n （1） and [Cd（tdc）（bib）]n （2） （Hgtdc = 3,4-thiophenedicarboxylic acid, bip = 1,3-bis-（imidazol-2-methyl）propane and bib = 1,4-bis（imidazol-2-methyl）butane）, have been synthesized and structurally characterized by single-crystal X-ray diffraction. Structural analyses reveal that 1 exhibits a two-dimensional （2D） layered network with 3-connected （6,3） topology, which is further connected into a three- dimensional （3D） supramolecular structure by intermolecular hydrogen bonds. However, 2 features a 2D network which can be rationalized as a 4-connected sql net. The results indicate the subtle difference of auxiliary bis（imidazol-2-methyl） ligands may lead to diverse architectures. Moreover, they exhibit luminescence emission in the solid state at room temperature.

Theoretical Study on the Reaction Mechanism of o-Aminophenol, Acetic Acid and Phosphorus Oxytrichloride One-pot to Form 2-Methyl Benzoxazole

The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the GGA/PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Two possible reaction pathways were investigated in this study. The result indicates that the reaction Re→TS1→IM1→TSA2→IMA2→TSA3→IMA3→TSA4→IMA4→TSA5→P2 is the main pathway, the activation energy of which is the lowest. Re→TS1→IM1 is the rate-limiting step, with the activation energy being 221.54 kJ·mol^(-1) and the reaction heat being 10.06 kJ·mol^(-1). The dominant product predicted theoretically is in agreement with the experiment results.

Interaction of N-(2-Methyl Thio Phenyl)-2-Hydroxy-1-Naphthaldimine with Tin Dioxide Nanoparticles: A Spectroscopic Approach

The interaction of N-(2-methyl thiophenyl)-2-hydroxy-1-naphthaldimine (NMTHN) with tin dioxide nanoparticles (SnO2 NPs) has been investigated by spectroscopic tools such as absorption and fluorescence spectroscopy. Absorption spectroscopy reveals the formation of ground state complex. Fluorescence spectroscopy has been used to study the signatures of fluorescence quenching. SnO2 NPs are found to quench the intrinsic fluorescence of NMTHN via static and dynamic quenching. The deviation from linearity in the Stern-Volmer plot has been observed.

XRD Pattern of Liquid Crystal Monomer Acrylate That Conjugated with Cholesterol and p-Hydroxyphenyl-2-Methyl Butanoic

It was successfully synthesized liquid crystal monomer acrylate that conjugated with two mesogens were cholesterol and p-hydroxyphenyl-2-methyl Butanoat which called MA （monomer cholesteryl acrylate） and monomer （S）-（＋）-4-（2-Methyl butanoat-l-butyloxy） phenyl 4-[1-（propenoyloxy） butyloxy] benzoate （MB）. Two monomers were characterized by DSC （differential scanning calorimetry）, POM （polarization optical microscopy） and XRD （X-ray diffraction）. Mesophase temperatures of MA and MB are 81.28 ~C and 54.36~C, respectively. Textures analysis by POM shows that MA was oily streak and MB was schlieren. XRD pattern shows the strongest three peaks of MA at room temperature which are （20, deg）： 2.7153, 5.2992 and 18.8500. The Strongest three peaks of MB at room temperature are （20, deg）： 9.1726, 9.7707 and 12.5389. XRD pattern of MA and MB at mesophase and above mesophase temperature that each peaks disappear.

钼负载型催化剂上乙烯与2-丁烯歧化制丙烯

通过研究不同载体负载Mo催化剂的乙烯和2-丁烯歧化制丙烯的反应性能,考察K、Mg和La等金属助剂和P、B、F和Cl等非金属助剂对Mo基催化剂活性和稳定性的影响,表明K、Mg和La有利于提高催化剂的稳定性。在此基础上,研制出在较低反应温度下具有较高活性和选择性的Mo/Z催化剂,在固定床反应器、60～70℃、1 0MPa和乙烯/2-丁烯摩尔比1 5～3的条件下,MgMo/Z上的乙烯和2-丁烯歧化反应连续进行120h,2-丁烯转化率为60%～90%,丙烯选择性达90%以上。

负载型杂多酸催化2-丁烯与醋酸直接酯化

采用加热回流法制备了SiO2负载磷钨酸催化剂,并用于催化2-丁烯与醋酸的直接酯化反应;考察了反应条件对酯化反应的影响;用电导率法测定了催化剂的活性组分磷钨酸在产物中的溶脱量;采用傅里叶变换红外光谱、吡啶吸附红外光谱、BET比表面积测定等方法对失活催化剂进行了表征并探讨了催化剂的失活原因。实验结果表明,酯化反应的优化条件为:反应温度110℃、反应压力1.5MPa、n(2-丁烯):n(醋酸)=2、反应时间9h、催化剂用量m(磷钨酸):m(醋酸)=0.03、水用量V(水):V(醋酸)=0.02,在此条件下,醋酸的转化率为33.5%,醋酸仲丁酯的选择性为92.7%;催化剂重复使用3次后失活,磷钨酸的最大溶脱量约54%,失活催化剂中磷钨酸的Keggin结构被破坏,L酸酸量下降,B酸完全消失。

预处理条件对MgMo/MCM22催化剂乙烯与2-丁烯岐化制丙烯反应性能的影响

研究了不同预处理条件下MgMo/MCM 2 2催化剂的乙烯和 2 -丁烯歧化制丙烯反应性能 ,考察了催化剂失活机理和再生条件 ,表明催化剂经氧化性气氛 (空气 )或惰性气体 (N2 )预处理后都表现出较高活性和稳定性 ,而氢气预处理却降低反应性能 ;催化剂积碳是催化剂失活的主要原因 ,失活催化剂于 5 5 0℃空气中烧碳后 。

1,2-丙二醇对可生物降解聚丁二酸丁二醇酯的共聚改性

以丁二酸、丁二醇和1,2-丙二醇为原料,采用溶液结合熔融缩聚合成法,得到了一系列聚(丁二酸丁二醇酯-co-丁二酸1,2-丙二醇酯)共聚物P(BS-co-PS)。利用1HNMR、GPC和X射线衍射等方法对共聚物的组成、分子量及其分子量分布、热学性能、结晶性能、力学性能等进行了研究。结果表明:反应4h,即可得到数均分子量60000以上的聚(丁二酸丁二醇酯-co-丁二酸1,2-丙二醇酯)共聚物P(BS-co-PS),分子量分布均小于2.0;随着1,2-丙二醇添加量的增加,共聚物的结晶度降低,熔点下降,但断裂伸长率明显增加,当添加量为30%(摩尔分数)时,断裂伸长率达到417%,表明共聚物具有良好的延展性能;所有共聚物的热分解温度均在300℃以上,具有良好的热稳定性。

浅谈六氟-2,3-二丁酮的合成方法

浅谈了六氟-2,3-二丁酮的合成方法,并对其路线进行了比较和评价。使用三氧化铬(CrO_3)作为氧化剂,以顺反六氟二氯丁烯(R1316)混合物为原料,其目标产物的收率最高为31%;以1,1,1,4,4,4-六氟-2-丁烯为原料,其目标产物的收率为26.6%。充分利用生产三氟二氯乙烷(HCFC-123)过程中产生的废弃物六氟二氯丁烯(R1316)混合物制备六氟-2,3-二丁酮的方法最有工业化前景和研究价值。

苯与2-丁烯烷基化反应的热力学分析

对苯与2-丁烯烷基化反应进行了热力学计算,得到不同反应温度下的焓值、吉布斯自由能和反应平衡常数,并研究了温度、反应物摩尔比以及原料中杂质对该反应热力学平衡的影响。结果表明:在此反应体系下,生成叔丁基苯的平衡转化率最大,更易发生;升高温度和提高反应物物质的量比,均有利于增大热力学平衡时仲丁基苯选择性;2-丁烯原料中杂质对烷基化基本无影响。

生物可降解聚丁二酸/2,2-二甲基丁二酸丁二酯系列共聚物的合成与性能研究

采用丁二酸(SA)、1,4-丁二醇(BD)、2,2-二甲基丁二酸(2MSA)合成了一系列聚丁二酸/2,2-二甲基丁二酸丁二酯共聚物(PBS-2M),利用DSC、1H-NMR和X射线分析等测试手段对共聚物组成、热力学性能、结晶性能、等温结晶行为进行了研究。结果表明,2,2-二甲基丁二酸共聚单元的引入显著改变了聚丁二酸丁二酯(PBS)的热学性能,利用Hoffman-Week曲线得到的共聚物平衡熔点随共聚组分含量的增加显著降低,玻璃化转变温度亦有所降低,结晶熔点则符合无规共聚物的Flory方程。此外,利用Avrami方程对均聚物PBS以及共聚物PBS-2M-20分别进行了等温结晶行为研究,结果表明,共聚使结晶速率降低,PBS和PBS-2M-20的Avrami指数分别介于2.8～3.0和2.6～2.8之间,结晶方式为三维生长异相成核,X射线分析证明共聚不影响晶体结构。

2,3-二氯-1,1,1,4,4,4-六氟-2-丁烯的应用研究

综述了2,3-二氯六氟-2-丁烯的应用情况。

聚丁二酸丁二醇酯和1,2-己二醇的共聚改性

以1，4-丁二酸、1，4-丁二醇和1，2己二醇为原料，采用直接熔融缩聚的方法，合成得到聚丁二酸丁二醇酯（PBS）和一系列聚（丁二酸丁二醇酯-CO-丁二酸1，2-己二醇酯）（PBSH）共聚物。采用乌氏黏度计、^1HNMR、DSC和流变仪等手段对其分子量、化学结构、热学性能、流变行为和力学性能进行研究。结果显示：随着1，2-己二醇摩尔分数的增加，相应PBS共聚酯的熔点（Tc）、结晶温度（Tc）、结晶度（Xc）、弯曲强度、拉伸强度逐渐降低，断裂伸长率明显增加；另外，1，2-己二醇的加入对PBS的零切黏度（ηc）、储能模量（G’）和损耗模量（G″）也有一定的影响。

E-4-乙酰氧基-2-甲基-2-丁烯-1-醛的合成研究

根据Kornblum反应,采用二甲基亚砜(DMSO)氧化E-1-乙酰氧基-4-氯-3-甲基-2-丁烯(ACMB)合成E-4-乙酰氧基-2-甲基-2-丁烯-1-醛(AMBA)。在实验过程中,采用气相色谱跟踪,研究了反应时间、反应温度和催化剂用量等因素对主副产物收率的影响并确定了较佳反应条件:反应时间24 h,反应温度80℃,原料缓慢滴加,KH2PO4:K2HPO4:ACMB=0.14:1.27:1(摩尔比),催化剂用量与原料ACMB比为0.12:1(摩尔比)。同时,对从未报道过的副产物E-1-乙酰氧基-4-甲巯基-3-甲基-2-丁烯(AMMB)进行了结构鉴定,并推测了其形成机理。

六氟-2-丁烯的合成研究进展

六氟-2-丁烯(HFC-1336)ODP值为零,GWP值很低(GWP100 yr ITH=9.4(NOAA)),是发泡剂HCFC-141b的理想替代品之一。对其合成方法进行了文献综述,在文献基础上得出以六氟-2,3-二氯-2-丁烯(R1316)为原料经两步反应合成HFC-1336的工艺具有工业化应用前景。

聚2-甲基丁二酸1,4-丁二醇酯对PVC的增塑及表征

采用2-甲基丁二酸和1,4-丁二醇在催化剂钛酸四丁酯作用下,通过熔融缩聚的方法合成了聚2-甲基丁二酸1,4-丁二醇酯,并将其作为增塑剂用于制备软质聚氯乙烯(PVC)。采用红外光谱(FT-IR)和核磁共振(1H NMR)对聚酯的结构进行了表征。通过扫描电镜(SEM)、动态力学分析(DMA)、拉伸测试对该聚酯增塑剂的增塑效果进行表征。结果表明:聚2-甲基丁二酸1,4-丁二醇酯与PVC相容性良好,可大大改善PVC材料的柔软性、降低PVC的玻璃化转变温度,增塑效果良好。与小分子增塑剂DOP相比,聚2-甲基丁二酸1,4-丁二醇酯具有优越的耐抽出性、耐挥发性和耐迁移性,提高了PVC材料的使用寿命。

Synthesis and Structure of Chromium Complexes with New Tetradentate Schiff Base N202-Type Ligand

In this research two chromium（II][） and （VI） complexes of tetradentate Schiff bases have been prepared by condensing of salicylaldehyde with 4-methyl 1,2-phenylenediamine. Schiff base complexes of chromium（Ill） have been employed to design and synthesize polynuclear complexes. So they have played an important role in molecular magnetism. Synthesized complexes were characterized by elemental analysis, IR, molar conductivity and NMR. The free ligands were alsc characterized by 1H, 13C NMR spectra. The 13C NMR and IR spectra of free ligand and the complexes are compared and discussed.

Synthesis and Crystal Structure of(E)-Ethyl 2-(4-(2,4-dimethoxybenzylideneamino)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazol-3-ylthio)acetate

The crystal structure of the title compound（E）-ethyl 2-（4-（2,4-dimethoxy benzylide-neamino）-5-（3,4,5-trimethoxyphenyl）-4H-1,2,4-triazol-3-ylthio）acetate（4,C24H28N4O7S,Mr = 516.17） was synthesized and determined by X-ray single-crystal diffraction.The crystal belongs to the monoclinic system,space group P21/n with a = 13.162（2）,b = 8.4506（13）,c = 22.602（4） ,β = 99.888（3）°,μ = 0.183 mm-1,V = 2476.5（7）3,Z = 4,Dc = 1.385 g/cm3,F（000） =1088,T = 110（2） K,R = 0.0426 and wR = 0.1216 for 3859 observed reflections with I 2σ（Ⅰ）.