Cr/MgO催化剂上乙腈和甲醇选择性合成丙烯腈的研究

用浸渍法制备了系列MgO负载过渡金属氧化物催化剂，比较了这些催化剂的催化性能，详细考察了Cr／MgO催化剂的活性组份含量、焙烧温度及反应温度等因素对乙腈和甲醇选择性合成丙烯腈的影响。结果表明，对于Cr／MgO催化剂，当负载量3％时催化性能最佳，过高的负载量对生成丙烯腈的选择性影响不大，但乙腈转化率呈下降趋势，焙烧温度对生成丙烯腈选择性的影响不大，但经600℃焙烧的催化剂乙腈转化率最高，随着反应温度提高，乙腈转化率提高，而生成丙烯腈选择性400℃左右出现最高值，CO2-TPD表明，催化剂强吸附碱中心越多，越有利于乙腈和甲醇选择性合成丙烯腈反应，Cr／MgO催化剂中引入Na2O后，提高了乙腈的转化率，而生成丙烯腈的选择性降低。     

不同介质凝胶体系中草酸钙结晶的研究

研究了五种不同介质（水、氯化钠、合成尿、正常人尿液和尿石患者尿液）的凝胶体系中草酸钙（CaC2O4）晶体的生长,及各种体系中防石药物柠檬酸钾（K3cit）对CaC2O4生长的影响.没有加K3cit时,CaC2O4晶体以一水草酸钙（calcium oxalate monohydrate, COM）为主要物相,但在氯化钠和合成尿的凝胶体系中同时出现了二水草酸钙（calcium oxalate dihydrate, COD）和三水草酸钙（calcium oxalate trihydrate, COT）,肾结石患者尿液中出现COD,而正常人尿液中没有COD和COT生成.加入K3cit后,水、氯化钠和合成尿介质的凝胶体系中,COT的含量显著增加,患者尿液中产生大量COD,而正常人尿液中出现了少量的COD和极个别的COT.COT的增加与低温、体系中高的离子强度及金属离子等因素有关.K3cit具有诱导COD和COT的生成、减小COM晶体比表面积的作用,从而有利于防治草酸钙结石的形成.     

微乳液增敏钼(Ⅵ)-3′,5′-二溴水杨基荧光酮络合物光谱探针测定蛋白质

研究了在乳化剂OP微乳液介质中钼（Ⅵ）-3′,5′-二溴水杨基荧光酮(3′,5′-DBSF)-蛋白质体系的相互作用和吸收光谱情况。在最佳条件下,牛血清蛋白质含量在0～10mg／L范围内服从比尔定律;同时测得络合物与蛋白质的结合数n=93。乳化剂OP微乳液引入到蛋白质的测定中提高了体系的灵敏度。结果表明：该法具有很高的灵敏度、选择性和稳定性,可直接用于人尿、奶粉和人血清样品的定量测定。     

混配型配合物Ni(mnt)(bipyO2)的合成与气敏性能

以cis-1,2-二氰基乙烯-1,2-二硫醇钠(Na2(mnt))、2,2′-联吡啶-1,1′-二氧化物(bipyO2)和NiCl2为原料,合成了一种具有大共轭体系的混配型配合物.用元素分析、差热 热重分析、摩尔电导、红外和紫外光谱对配合物进行表征.该配合物化学式为Ni(mnt)(bipyO2),平面正方形结构,属电中性物质,热分解温度高于335 ℃.不溶于水和常规有机溶剂,可溶于DMSO.该配合物是一种氨敏材料,用它制作的传感器对氨气具有良好的敏感性和选择性;当工作电压为10 V时,在氨气浓度小于2.6 mmol•L－1的范围,传感器的输出信号对氨气呈线性响应.传感器的平均回收率为100.2％,响应时间为20 s,恢复时间为45 s.可用于微量氨的定量分析.     

Boyle temperature and cubic equations of state

The sensitivity of Boyle temperature to changes in parameters appearing in cubic equations of state and to volume shift is analyzed. Analytical expressions for the Boyle temperature and for the dependency to the shift of the equation of state are given for the most common cases of the alpha function.     

Solid–liquid–gas equilibrium of the naphthalene–biphenyl–CO2 system: Measurement and modeling

The first and last melting points (FLMP) method was employed to measure the melting temperature–composition (T–w$T–w$) data at solid–liquid–gas (SLG) equilibrium for the naphthalene–biphenyl–CO₂ system. Results show that the system's phase diagram is simple eutectic under all investigated pressures (0.1, 3.0, 6.0 and 8.0 MPa), and the system's eutectic composition is almost constant. The (T–w$T–w$) data measured with a high-pressure differential scanning calorimetry are in good agreement with these from FLMP. The semi-predictive model using solubility data (SMS) and the calculation model combining with G^E models (CMG) for binary systems were extended to this ternary system. For the SMS model, the Peng–Robinson equation of state (PR-EoS) with the van der Waals one-fluid mixing rule was used to correlate the solubility data of the two solutes in CO₂ to obtain the two interaction parameters k₁₂ and k₁₃ and calculate the fugacity coefficients of the solutes in the liquid and vapor phases; the UNIFAC method was also applied to the activity coefficient of the solutes in the liquid phase. For the CMG model, the PR-EoS combining respectively the MHV1, LCVM, and modified LCVM (mLCVM) mixing rules was applied to the fugacity coefficients of the solutes. Results show that the CMG model with MHV1 gives the best prediction of the system's SLG equilibrium, while the SMS model and the CMG model with mLCVM provide comparable and acceptable results.     

β-Amino alcohol selectors for enantioselective separation of amino acids by ligand-exchange capillary zone electrophoresis in a low molecular weight organogel

A new family of copper ligand-exchange selectors, L- or D-β-amino alcohols, is employed for the chiral separation of D,L-dansyl-amino acids, unmodified amino acid racemates, phenylalanine and tryptophan, and β-blocker L,D-propranolol by SDS-micellar electrokinetic chromatography and by electrophoretic chromatography in a low molecular weight organogel (LMOG)-filled capillary. The LMOG comprised a self-assembled fibrillar gel of trans-(1S,2S)-1,2-bis-(dodecylamido) cyclohexane in methanol. The di-L-valinol-copper complex exhibited the best performance on LMOG-CE compared with all other β-amino alcohol-copper selectors. The dependence of chiral resolution on the pH*, the ratio between the copper and the L-valinol ligand and the concentration of added selector complex in the run buffer were investigated revealing a marked difference between the activity of the copper-valinol and the previously studied copper-valine selector. The optimal separation conditions were achieved using a 2:1 valinol/copper ratio, in accordance with the 2:1 structure of the complex, which was proven by single crystal and powder X-ray diffractions and by elemental analysis. Unlike the copper-valine selectors that could be used only under acidic conditions (pH* 3.5), the copper-valinol selectors could be used under near-neutral conditions and even at pH* 9.1. A comparison between SDS-micellar electrokinetic chromatography and LMOG-CE under otherwise identical conditions revealed a significant superior separation on the LMOG-filled capillaries.     

Synthesis of seco-chlorinated derivatives of phenanthroindolizidine precursors via Friedel-Crafts reaction

In the course of synthesizing 3-demethyltylophorine (1) by Lewis acid catalyzed intramolecular Friedel-Crafts reaction starting from N-(3-hydroxy-2,6,7-trimethoxy-phenanthr-9-ylmethyl)-2-chloromethylpyrrolidine, two chlorinated phenanthrene derivatives N-(4,10-dichloro-3-hydroxy-2,6,7-trimethoxyphenanthr-9-ylmethyl)-2-chloromethylpyrrolidine (4) and N-(4-chloro-3-hydroxy-2,6,7-trimethoxyphenanthr-9-ylmethyl)-2-chloromethylpyrrolidine (5) were obtained. The structures of these compounds were determined by spectroscopic analysis.     

CaL-B a highly selective biocatalyst for the kinetic resolution of furylbenzthiazole-2-yl-ethanols and acetates

A highly stereoselective enzymatic kinetic resolution of novel various substituted racemic furylbenzthiazole-2-yl-ethanols and their acetates has been developed. Both processes, the enzymatic acylation of the racemic alcohols and the enzymatic methanolysis of racemic acetates yielded highly enantiomerically enriched (ee >98%) resolution product, when CaL-B was used as a biocatalyst in acetonitrile. The absolute configuration of the obtained (R)-(+)-1-(5-(4-chlorobenzo[d]thiazol-2-yl)furan-2-yl)ethanol was determined by a detailed ¹H NMR study of rac- and (+)-1-(5-(4-chlorobenzo[d]thiazol-2-yl)furan-2-yl)ethanol Mosher derivatives.