甲醇-苯-l-辛基-3-甲基咪唑四氟硼酸盐物系汽液平衡的测定

在101.32 kPa下,用改进的Othmer釜测定了甲醇-苯-1-辛基-3-甲基咪唑四氟硼酸盐([OMIM]BF4)物系的等压汽液平衡数据;采用UNIFAC方程对实验数据进行了关联。实验结果表明,加入离子液体[OMIM]BF4使汽液平衡线偏离甲醇-苯二组分物系的汽液平衡线,[OMIM]BF4含量越大,偏离程度越大。[OMIM]BF4具有明显的盐析效应,能增大甲醇与苯的相对挥发度,随[OMIM]BF4含量的增加,甲醇与苯的相对挥发度增加,当x([OMIM]BF4)=30%时,甲醇-苯物系的共沸点消失。[OMIM]BF4可作为甲醇-苯物系萃取精馏的溶剂。     

乙酸甲酯-甲醇-1-乙基-3-甲基咪唑四氟硼酸盐物系等压汽液平衡数据的测定与关联

在101.3kPa下,用改进的Othmer釜测定了乙酸甲酯-甲醇-1-乙基-3-甲基咪唑四氟硼酸盐([emim]BF4)三组分物系的等压汽液平衡数据。实验结果表明,加入[emim]BF4,乙酸甲酯-甲醇二组分物系的汽液平衡线发生偏离,离子液体摩尔分数越大,偏离程度越大;[emim]BF4表现出盐效应,使乙酸甲酯对甲醇的相对挥发度增加。用NRTL模型对汽液平衡的实验数据进行了关联,得到二组分交互作用参数。采用该模型参数,乙酸甲酯-甲醇-[emim]BF4三组分物系乙酸甲酯的汽相摩尔分数的实验值与计算值的绝对平均偏差为0.003,温度平均偏差为0.3K。     

甲醇-碳酸二甲酯-1-辛基-3-甲基咪唑四氟硼酸盐物系的等压汽液平衡测定及UNIFAC关联

在101.32 kPa下,用改进的Othmer汽液平衡釜测定了甲醇-碳酸二甲酯(DMC)-1-辛基-3-甲基咪唑四氟硼酸盐([omim]BF4)物系的等压汽液平衡数据;采用UNIFAC方程对实验数据进行了关联,得到了新基团—OCOO—与—CH2—,CH3OH,—[mim]BF4基团间的UNIFAC作用参数。与传统基团划分的UNIFAC模型关联结果相比,采用新基团划分法推算得到的汽液平衡数据与实验值偏差更小。实验结果表明,加入离子液体[omim]BF4使汽液平衡线偏离甲醇-DMC二组分物系的汽液平衡线,[omim]BF4含量越大,偏离程度越大;[omim]BF4具有明显的盐析效应,能消除甲醇-DMC物系的共沸点;[omim]BF4可作为甲醇-DMC物系萃取精馏的溶剂;UNIFAC方程可用于预测甲醇-DMC-[omim]BF4物系的汽液平衡。     

乙酸乙酯-乙醇-1-乙基-3-甲基四氟硼酸咪唑盐物系等压汽液平衡数据的测定

在101.32 kPa 下,用改进的 Othmer 釜测定了含离子液体1-乙基-3-甲基咪唑四氟硼酸盐([EMIM]BF_4)的乙酸乙酯-乙醇物系的等压汽液平衡数据。实验结果表明,加入[EMIM]BF_4使汽液平衡线偏离乙酸乙酯-乙醇二组分物系的汽液平衡线,[EMIM]BF_4含量越高,偏离程度越大;[EMIM]BF_4表现出盐效应,使乙酸乙酯对乙醇的相对挥发度发生改变,消除了乙酸乙酯-乙醇物系的共沸点;[EMIM]BF_4含量越高,盐效应越明显,随[EMIM]BF_4含量的增加,乙酸乙酯对乙醇的相对挥发度增加。[EMIM]BF_4可以作为乙酸乙酯-乙醇物系萃取精馏的溶剂,适宜的[EMIM]BF_4摩尔分数约为20%。     

乙酸乙酯-乙醇-1-辛基-3-甲基咪唑四氟硼酸盐物系汽液平衡数据的测定

在101.32 kPa下,用改进的Othmer汽液平衡釜测定了乙酸乙酯-乙醇-1-辛基-3-甲基咪唑四氟硼酸盐([omim]BF_4)三组分物系的等压汽液相平衡数据。采用NRTL方程对实验数据进行了关联,得到方程参数,活度系数的计算值与实验值的偏差为3.12%。实验结果表明,加入[omim]BF_4使汽液平衡线偏离乙酸乙酯-乙醇二组分物系的汽液平衡线,[omim]BF_4含量越大,偏离程度越大;[omim]BF_4具有明显的盐析效应,能够增大乙酸乙酯对乙醇的相对挥发度;当x([omim]BF_4)为10%时,乙酸乙酯-乙醇物系的共沸点消失,随[omim]BF_4含量的增加,乙酸乙酯对乙醇的相对挥发度增加。     

甲醇-乙腈-l-丁基-3-甲基咪唑四氟硼酸盐三组分物系的汽液平衡

在101.32 kPa下,用CE-2型Othmer汽液平衡釜测定了甲醇-乙腈-l-丁基-3-甲基咪唑四氟硼酸盐([bmim]BF4)三组分物系的等压汽液平衡数据;采用UNIFAC方程对实验数据进行了关联。实验结果表明,与未加入[bmim]BF4相比,加入[bmim]BF4后甲醇-乙腈二组分物系的汽液平衡线产生偏离,[bmim]BF4含量越高,偏离程度越大;[bmim]BF4具有明显的盐析效应,当[bmim]BF4的含量为10%(x)时,甲醇-乙腈物系的共沸点消失;UNIFAC方程可用于预测甲醇-乙腈-[bmim]BF4三组分物系的汽液平衡。     

1-乙酸乙酯基-3-甲基咪唑四氟硼酸盐离子液体用作润滑剂的探讨

合成了含羧酸酯基官能团的功能化离子液体--1-乙酸乙酯基-3-甲基咪唑四氟硼酸盐([EAMIM]BF4),考察了其物化性质、高低温下的摩擦学性能以及对传统润滑油添加剂的相溶性和感受性,并选择含有相同烷基的1-丁基-3-甲基咪唑四氟硼酸盐传统离子液体([BMIM]BF4)作为对比。结果表明：两种离子液体具有较好的低温流动性、低的蒸发损失和高的热稳定性;能溶解部分具有强极性和杂环化合物的传统润滑油添加剂,但不能溶解大多数常用的油溶性添加剂,[EAMIM]BF4对添加剂的溶解性比[BMIM]BF4弱;在室温及高温条件下,[EAMIM]BF4由于粘度较大减摩性稍差,但抗磨性比[BMIM]BF4强;极压抗磨剂亚磷酸二正丁酯能提高[BMIM]BF4的抗磨作用,但与[EAMIM]BF4呈现出对抗效应,导致其润滑性能降低。     

1-丁基-3-甲基咪唑六氟磷酸盐萃取香豆素

实验采用疏水性离子液体1-丁基-3-甲基咪唑六氟磷酸盐([C_4mim][PF_6])代替挥发性有机溶剂,由水相中萃取香豆素。采用紫外分光光度法测定了香豆素质量浓度,考察了温度、pH值、相比、香豆素质量浓度、萃取时间等因素对萃取效果的影响。结果表明,在10～50℃和pH=1～11条件下,温度和pH值对萃取效果几乎无影响;当萃取时间为10 min、V(香豆素水溶液):V([C_4mim][PF_6])=3:1、香豆素质量浓度为1.0g/L时,萃取效果最好;在该条件下,以100mL[C_4mim][PF_6]为萃取剂,平均萃取率达94.55%。离子液体中的香豆素用3倍体积量的NaOH水溶液反萃取3次,可将香豆素完全转移到水相;离子液体相用蒸馏水洗至中性,80℃减压干燥5 h后可重新使用。     

1-(3-磺酸基)丙基-3-甲基咪唑磷钨酸盐的制备及其催化性能

以N-甲基咪唑、1,3-丙烷磺内酯、磷钨酸为原料,采用两步法合成了1-(3-磺酸基)丙基-3-甲基咪唑磷钨酸盐([MIMPS]_3PW_(12)O_(40))催化剂。利用X射线衍射、傅里叶变换红外光谱(FTIR)、热重-示差扫描量热分析对催化剂进行了表征,表征结果显示,[MIMPS]_3PW_(12)O_(40)催化剂中有8个结晶水,具有磷钨酸的Keggin结构和良好的热稳定性。将该催化剂用于合成乙二醇丁醚醋酸酯(BAC),在最佳工艺条件(反应时间2.0 h,乙二醇丁醚与醋酸的摩尔比1.2:1,反应温度120℃,催化剂与反应物的质量比0.04,带水剂环己烷与反应物的质量比0.3)下,BAC收率可达99.3%。反应后催化剂易分离,重复使用9次后BAC收率为86.8%。FTIR表征结果显示,产物为BAC,没有副产物生成。     

溶剂抽提及1-乙基-3-甲基咪唑醋酸盐热溶解聚对羊肠湾次烟煤萃取行为的影响

溶剂萃取是制备超净煤和研究煤分子结构的重要方法之一,对于实现煤资源高效清洁转化具有重要意义。选取中国宁东羊场湾 (YCW) 煤作为研究对象,考察多种溶剂及添加离子液体1 乙基 3 甲基咪唑醋酸盐(［Emim］［AC］)对煤萃取效果的影响。结果表明,煤的萃取产率从大到小的顺序遵循着含氮类、醇类、酮类、烃类的规律。所选取的9种溶剂中,二甲基亚砜对 YCW 煤的萃取产率最高。对于同类溶剂而言,极化率越大,萃取产率越高。研究还发现,离子液体 ［Emim〖DK(〗］［〖DK)〗AC］ 的添加可以显著提高 YCW 煤在溶剂中的萃取产率。此外,离子液体的回收率也可达到915%。     

气相色谱法同时测定苯甲醛、苯甲醇和苯甲酸

系统地建立了一套简单、快速、能同时定量分析甲苯液相催化氧化主要产物苯甲醛、苯甲醇及苯甲酸的气相色谱分析方法。采用FFAP毛细管柱和氢火焰离子化检测器(FID),以邻硝基甲苯为内标标定苯甲醛、苯甲醇,以邻苯二甲酸二甲脂为内标标定苯甲酸。结果表明,苯甲醛、苯甲醇、苯甲酸样品的平均回收率和标准偏差(RSD)分别为105.39%,101.94%,97.18%和3.19%,3.71%,1.66%。该分析方法简单、快速、精度高。     

苯甲醇液相氧化制苯甲醛催化剂的研究进展

综述了"绿色"液相氧化苯甲醇制苯甲醛催化剂的研究进展,以负载型贵金属催化剂、非贵金属氧化物催化剂、杂多酸及其负载型催化剂、离子液体催化体系和负载型过渡金属有机络合物催化剂为重点,评述了各类催化剂的特性和近年来的研究进展,展望了"绿色"液相氧化苯甲醇制苯甲醛催化剂的发展方向,提出了研制高效、"绿色"催化剂仍是苯甲醇液相氧化过程中获得高收率苯甲醛的关键。     

Ab Initio Calculation of Room Temperature Ionic Liquid 1-Ethyl-3-Methyl-Imidazolium and AlCl3

The Hartree-Fock method has been employed to investigate the electronic structures of EMIM＋（1- ethyl-3-methylimidazolium＋）, AlCl4^-, and EMIM＋-AlCl4^-. Full optimization and frequency analyses of EMIM＋, AlCl4^-, ten initial EMIM＋-AlCl4^- geometries have been carried out using the Gaussian-94 soft-package at 6- 31＋G（d,p） basis set level for hydrogen, carbon, nitrogen, chlorine, and aluminum atoms. The electronic structures of the lowest energy of EMIM＋-AlCl4^-pairs, single EMIM^＋, and AlCl4^- have been comparatively studied. The calculated results showed that the optimized EMIM^＋-AlCl4^-pair conformer of lowest energy was AlCl4^-outside the five-ring plane between methyl group and ethyl group with a H6--C122 distance of 2.7 A. The frequency analyses suggested that all stationary points were minimum points because of no imaginary frequency appearing, and the assigned frequencies were in agreement with experimental report. The interaction energy between EMIM^＋ and AlCl4^-was 776.2 kJ/mol.     

DFT Calculation of Room Temperature Ionic Liquid 1-Ethyl-3-Methyl-Imidazolium Chlorocuprate (Ⅰ)

The density functional theory (DFT) has been employed to investigate the electronic structures of EMIM ( 1-ethyl-3-methylimidazolium ), CuCl2-, Cu2Cl3- and EMIM -CuCl2-, EMIM -Cu2Cl3- pairs.Full optimization and frequency analyses of EMIM , CuCl2-, Cu2Cl3-, eight initial EMIM -CuCl2-, and six initial EMIM -Cu2Cl3- geometries have been carried out using Gaussian-94 software-package at 6-31 G (d,p) basis set level for hydrogen, carbon, nitrogen, chlorine atoms and the Hay-Wadt effective core potential for copper atoms. The electronic structures of the lowest energy of EMIM -CuCl2-, EMIM -Cu2Cl3-pairs, single EMIM , CuCl2-, and Cu2Cl3- have been comparatively studied. The calculated results showed that the optimized EMIM -CuCl2- pair conformer of the lowest energy was five ring moiety parallel to CuCl2- plane with a distance of around 3.5A, while EMIM -Cu2Cl3- pair conformer of the lowest energy was five ring moiety of EMIM perpendicular to Cu2Cl3- plane with a distance of around 3.0 A between terminal chlorine atoms and 5-ring plane of EMIM~. The cohesion between cation and anion is electrostatic interaction and C-H-Cl hydrogen bonds are reinforced by charge assistance. The frequency analyses suggested that all stationary points are minimum points because of absence of imaginary frequency. The low energy of interaction caused by bulky asymmetry of EMIM , and charge dispersion of cation and anion give rise to low melting point of ionic liquids EMIM -CuCl2-, and EMIM -Cu2Cl3-. The interaction energy caused by the distance between cations and anions was investigated by single point energy scan.     

乙酸乙酯-乙腈-1-乙基-3-甲基咪唑三氟甲磺酸盐物系等压汽液平衡数据的测定

在101.32 k Pa下,用改进的Othmer釜测定了含离子液体1-乙基-3-甲基咪唑三氟甲磺酸盐([emim]OTf)的乙酸乙酯-乙腈物系的等压汽液平衡数据;采用NRTL方程对实验数据进行关联,关联效果良好。实验结果表明,加入[emim]OTf后,乙酸乙酯-乙腈二组分物系汽液平衡线发生偏离,[emim]OTf含量越高,偏离程度越大;[emim]OTf具有明显的盐析效应,当[emim]·OTf的含量达到5%(x)时,就可消除乙酸乙酯-乙腈物系的共沸点;[emim]OTf可作为乙酸乙酯-乙腈萃取精馏的萃取剂。     

DFT Calculation of Room Temperature Ionic Liquid 1-Ethyl-3-Methyl-Imidazolium Chlorocuprate （I）

The density functional theory （DFT） has been employed to investigate the electronic structures ofEMIM^＋（1-ethyl-3-methylimidazolium＋）, CuCl2^-, Cu2Cl3^- and EMIM^＋-CuCl2^-, EMIM^＋-Cu2Cl3^- pairs. Full optimization and frequency analyses of EMIM^＋, CuCl2^-, Cu2Cl3^-, eight initial EMIM^＋-CuCl2^-, and six initial EMIM^＋-Cu2Cl3^- geometries have been carried out using Gaussian-94 software-package at 6-3 I＋G （d, p） basis set level for hydrogen, carbon, nitrogen, chlorine atoms and the Hay-Wadt effective core potential for copper atoms. The electronic structures of the lowest energy of EMIM^＋-CuCl2^-, EMIM^＋-Cu2Cl3^- pairs, single EMIM^＋, CuCl2^-, and Cu2Cl3^- have been comparatively studied. The calculated results showed that the optimized EMIM^＋-CuCl2^- pair conformer of the lowest energy was five ring moiety parallel to CuCl2^- plane with a distance of around 3.5,A, while EMIM^＋-Cu2Cl3^- pair conformer of the lowest energy was five ring moiety of EMIM^＋ perpendicular to Cu2Cl3^- plane with a distance of around 3.0 ,A between terminal chlorine atoms and 5-ring plane of EMIM^＋. The cohesion between cation and anion is electrostatic interaction and C-H---Cl hydrogen bonds are reinforced by charge assistance. The frequency analyses suggested that all stationary points are minimum points because of absence of imaginary frequency. The low energy of interaction caused by bulky asymmetry of EMIM^＋, and charge dispersion of cation and anion give rise to low melting point of ionic liquids EMIM^＋-CuCl2^-, and EMIM^＋-Cu2Cl3^- . The interaction energy caused by the distance between cations and anions was investigated by single point energy scan.