Experimental densities,vapor pressures,and critical point,and a fundamental equation of state for dimethyl ether

Densities, vapor pressures, and the critical point were measured for dimethyl ether, thus, filling several gaps in the thermodynamic data for this compound. Densities were measured with a computer-controlled high temperature, high-pressure vibrating-tube densimeter system in the sub- and supercritical states. The densities were measured at temperatures from 273 to 523 K and pressures up to 40 MPa (417 data points), for which densities between 62 and 745 kg/m³ were covered. The uncertainty (where the uncertainties can be considered as estimates of a combined expanded uncertainty with a coverage factor of 2) in density measurement was estimated to be no greater than 0.1% in the liquid and compressed supercritical states. Near the critical temperature and pressure, the uncertainty increases to 1%. Using a variable volume apparatus with a sapphire tube, vapor pressures and critical data were determined. Vapor pressures were measured between 264 and 194 kPa up to near the critical point with an uncertainty of 0.1 kPa. The critical point was determined visually with an uncertainty of 1% for the critical volume, 0.1 K for the critical temperature, and 5 kPa for the critical pressure. The new vapor pressures and compressed liquid densities were correlated with the simple TRIDEN model. The new data along with the available literature data were used to develop a first fundamental Helmholtz energy equation of state for dimethyl ether, valid from 131.65 to 525 K and for pressures up to 40 MPa. The uncertainty in the equation of state for density ranges from 0.1% in the liquid to 1% near the critical point. The uncertainty in calculated heat capacities is 2%, and the uncertainty in vapor pressure is 0.25% at temperatures above 200 K. Although the equation presented here is an interim equation, it represents the best currently available.     

用高分子冠醚和高分子液晶混合物作毛细管气相色谱固定液的研究

作为毛细管气相色谱固定液,对高分子液晶和高分子冠醚的共混物和含冠醚的高分子液晶单一固定液进行了比较,结果表明它们具有大致相同的保留性能。     

Cu-Zn-Al-Zr合成二甲醚浆状催化剂的完全液相制备及表征

利用完全液相法,以不同加料顺序制备了Cu-Zn-Al-Zr浆状催化剂,采用X射线粉末衍射、氮吸附、程序升温还原、X射线光电子能谱和氨程序升温脱附对其进行了表征,考察了Cu-Zn-Al-Zr浆状催化剂在合成气一步法合成二甲醚反应中的催化性能。结果表明,不同加料顺序对催化剂性能有显著的影响; Zr与Al同时加入时,催化剂的活性组份分散均匀,易于还原,表面结构稳定,拥有与CuZnAl催化剂相似的强弱酸中心;当 Al/Zr=10/1时,催化剂的CO转化率和DME选择性与CuZnAl催化剂基本持平,但催化剂的流变性得到明显改善。     

含二苯并-18-冠-6酰胺型液晶冠醚钾配合物的合成和性质

合成了2个系列酰胺型液晶冠醚钾配合物，配合物的结构通过元素分析、IR、UV-Vis和AAS等方法表征。液晶行为通过DSC、POM、XRD等方法表征。实验结果表明，所有配合物均具有热致液晶性，且随分子末端烷氧基碳原子数增加，其熔点和清亮点呈规律性变化。与配体相比，配合物液晶态温度范围变宽。液晶相态类型发生改变，配体只有近晶相，而配合物既有近晶相，又有向列相。     

杂元素冠醚的研究（Ⅵ）──7，11－二硒杂苯并－13－冠－4铂配合物的合成及其催化硅氢化性能

合成了７，１１－二硒杂苯并－１３－冠－４及其铂配合物，并从底物的性质、反应温度、催化剂用量以及化学气氛四个方面考察了该配合物对烯烃与三乙氧基硅烷的硅氢加成反应的催化特性。与单硒杂冠醚配合物相比，该配合物对某些烯烃的催化活性较高，但催化反应需要的温度也较高．     

开链配体及手性冠醚仿生化学研究现状

综述了部分开链配体的络合行为,对手性冠醚的合成、分子识别及仿生功能的研究进行了评述,开链配体在络合行为上与环状化合物很相似,能与金属离子、中性分子形成络合物,手性冠醚的合成是一个活跃的研究领域,将手性冠醚用于手性识别、手性催化及仿生化学的研究日趋活跃,前景十分诱人。     

Crystal structures of the complexes of rare earth picrates with N, N, N'''', N''''-tetraphenyl-3, 6-dioxaoctanediamide

The complexes of rare earth picrate with N,N,N',N'-tetraphenyl-3,6-dioxaoctanediamide(TDD),Eu(picc(TDD)] 2CH3CN and [ Y(pic)3(TDD)],have been synthesized.The crystal structures reveal that TDD at is as n tetradentate ligand,forming a ring-like coordination structure with its oxygen atoms together with one oxygen atom of the bidentate pterate In the Eu(Ⅲ) complex,the europium ion with a larger ionic radius lies out of the ring,while in the Y(Ⅲ) complex,the yttrium ion with a smaller ionic radius enters the cavity of the ligand.The structures of the complexes are greatly affected by the ionic radii due to participation of the picrates in coordination.     

Preparation and characterization of Co- and homopoly(phenylene etherimideketone)s

Poly(phenylene etherimdeketone)s were prepared by Friedel–Crafts acylation type polymerization using P₂O₅? CH₃SO₃H 1 : 10 (w/v) mixtures. Most of these polymers were semicrystalline. T_gS ranged from 203 to 236°C and crystalline melt temperatures were observed between 306 and 435°C. All of the polymers exhibited high thermal stability and good solvent resistance. © 1993 John Wiley & Sons, Inc.     

Synthesis and characterization of fluorinated poly(aryl ether ketone)s containing 1,4-naphthalene moieties

The new monomer 2,2-bis[4-(4-{4-fluorobenzoyl}-1-naphthoxy)phenyl]hexafluoropropane ( 2 ) was synthesized in a two-step reaction sequence. 2,2-his[4-(1-naphthoxy)phenyl]-hexafluoropropane ( 1 ) was prepared using the Ullmann ether synthesis reaction of 4,4-(hex-afluoroisopropylidiene)diphenol with 1-bromonaphthalene. Friedel-Crafts acylation of 1 with 4-fluorobenzoyl chloride in methylene chloride containing dimethylsulfone selectively afforded 2 in 82% yield. The polycondensation of 2 with various bisphenols in DMAc in the presence of an excess of potassium carbonate as a condensation reagent was carried out at 165°C to quantitatively afford the corresponding fluorinated poly(aryl ether ketone)s containing 1,4-naphthalene moieties. Thermal analysis of the polymers showed them to have T_gs ranging from 194 to 230°C and to be thermally stable in air up with initial weight losses at about 500°C. In addition, these novel polymers exhibited excellent solubility in organic solvents including NMP, DMAc, and chloroform. © 1997 John Wiley & Sons, Inc.     

铜铁二元类水滑石化合物的制备及催化性质研究

利用共沉淀法合成了CuFe二元类水滑石化合物。测定了不同Cu/Fe比混合盐溶液随沉淀剂NaOH与Na₂CO₃加入,混合盐体系pH值变化情况,详细探讨了不同因素对类水滑石化合物制备的影响,得到了合成铜铁二元类水滑石化合物的适宜条件,制备出晶相单一、结晶度高的类水滑石化合物,并利用XRD、FTIR、TG-DTA对合成物进行表征。将合成的催化剂引入苯甲醛与正丙醇反应生成安息香异丙醚反应中, 苯甲醛转化率为58%,安息香异丙醚选择性接近于100%。