TODGA/[C2mim][NTf2]萃取Th4+的研究

研究了N,N,N',N'-四辛基-3-氧戊二酰胺(TODGA)溶于疏水性离子液体咪唑类离子液体1-乙基-3-甲基咪唑双三氟甲磺酰亚胺盐([C₂mim][NTf₂])中对硝酸水溶液体系中四价钍离子(Th⁴⁺)的萃取行为.详细考察了接触时间、酸度、Th⁴⁺浓度、TODGA浓度、温度对TODGA/[C₂mim][NTf₂]体系萃取性能的影响.作为对比,我们还考察了TODGA在传统有机溶剂异辛烷中对Th⁴⁺的萃取.结果表明:TODGA/[C₂mim][NTf₂]体系对Th⁴⁺的萃取是吸热反应,且在50 ℃下,能在5 min内达到平衡.萃取体系随着酸度对Th⁴⁺的萃取性能先降后增大;Th⁴⁺浓度的增大,TODGA浓度的降低,对Th⁴⁺的萃取性能下降.TODGA在离子液体萃取体系中比在有机体系中有更好的Th⁴⁺萃取效果,特别是在低酸条件下.通过萃取机理研究,推测出在低酸下萃取反应是离子交换且TODGA与Th⁴⁺配比为2∶1,在高酸下萃取是中性配位.     

一种可高温运行的离子液体电解质燃料电池

本文采用N-甲基咪唑为原料通过溴盐的中间步骤合成了1-乙基-3甲基咪唑磷酸二氢盐([Emim]H₂PO₄)离子液体。首先利用元素分析和核磁共振确定了其组成,并测量了该离子液体的粘度和电导性能,然后使用多孔的聚偏氟乙烯作为支撑制备了离子液体电解质复合膜,120 ℃时通过交流阻抗测得其电导率为2.7×10^-2 S·cm^-1。最后将该复合膜组装在单电池中测试了不同温度下的性能,常压下120 ℃时可获得0.85 mW·cm^-2的功率密度,结果表明该复合膜的质子传导可以完全不依赖水,从而能够实现高温操作。     

一类新型酯类离子液体的合成

以氯乙酸乙酯和氮杂环化合物(1-甲基咪唑、吡啶、N-乙基哌啶、N-甲基吗啉)为原料, 采用两步法合成了一类新型的酯类离子液体, 对合成的12个化合物进行了元素分析, ¹H NMR谱和一些物理性质的测定. 大多数化合物的熔点低于100 ℃, 为室温离子液体. 所合成离子液体的热稳定范围都比较宽, 性质稳定.     

CMPO/[Cnmim][NTf2]体系对Eu3+和UO22+的萃取行为

讨论了辛基(苯基)-N,N-二异丁基胺甲酰基甲基氧化膦(CMPO)/1-烷基-3-甲基咪唑双(三氟甲烷磺酰)亚胺盐([C_nmim][NTf₂],n=2,8,12)萃取体系分别对硝酸溶液中的铕离子(Eu³⁺)和铀酰根离子(UO₂²⁺)的萃取行为。主要研究了硝酸浓度、接触时间、温度、CMPO浓度对CMPO/[C_nmim][NTf₂]体系萃取性能的影响,并选取CMPO/[C2mim][NTf₂]体系对模拟高放废液中的镧锕元素进行了萃取分离。结果表明:随着离子液体侧链长度增长,萃取平衡时间逐渐延长;CMPO/[C2mim][NTf₂]体系对Eu³⁺的萃取是放热反应,萃取率随酸度增加而逐渐降低,对UO₂²⁺则是吸热反应,萃取率随酸度增加而逐渐升高;通过机理研究,推测出对Eu³⁺的萃取反应是离子交换,而对UO₂²⁺的萃取反应则是中性配位;CMPO/[C2mim][NTf₂]体系能有效的萃取模拟高放废液中的镧系、锕系元素,且在高酸下有一定的镧锕分离效果。     

手征性杂氮锗三环的合成及表征

本文报道了首次合成的具有手性的(4S)-1-羟基-4-羧基杂氮锗三环和(4S)-3-甲基-1-羟基-4-羧基杂氮锗三环，并运用IR、¹H NMR、MS等对其进行了表征。证据显示此化合物存在贯穿笼状结构的N→Ge配键。     

咪唑基离子液体非共价修饰的石墨烯结构与分散性

在离子液体氯化-1-烯丙基-3-甲基咪唑（AmimCl）存在的条件下,利用水合肼对氧化石墨烯进行同步还原,制备了一种可稳定分散在N,N-二甲基甲酰胺（DMF）和乙酸丁酯等有机溶剂中的离子液体改性石墨烯（IL-G）。运用红外光谱（FTIR）、紫外-可见吸收光谱（UV-Vis）、热失重分析（TGA）、原子力显微镜（AFM）、拉曼光谱（Raman）、X射线电子衍射（XRD）和X射线光电子能谱（XPS）对制备的改性石墨烯进行结构性能测试,结果表明离子液体AmimCl与石墨烯之间存在π-π和阳离子-π的相互作用,能较好的吸附在石墨烯表面。TGA测试表明IL-G中离子液体的比例约为7.20wt%。同时,AFM结果显示改性石墨烯剥离在DMF中的平均厚度是0.962nm。由于非共价改性石墨烯可再分散于DMF和乙酸丁酯中,通过紫外可见吸收光谱测得其最大分散浓度分别是1.69mg·mL^-1和1.12mg·mL^-1。     

烷基咪唑离子液体对脂肪酶催化酯水解反应活性的影响

考察了1-烷基-3-甲基咪唑类离子液体对柱状假丝酵母脂肪酶(CRL)催化橄榄油水解反应活性的影响,利用电导法确定了磷酸盐缓冲液中Br^-,Cl^-,[BF₄]^-系列咪唑离子液体的临界胶束浓度(CMC)和[PF₆]^-系列咪唑离子液体的溶解度.结果显示,离子液体的阴、阳离子对酶活性的影响规律与离子液体的Kosmotropicity性质无明显关联,但与离子液体在体系中的含量密切相关,在最适离子液体含量时,酶活性达到最高;阳离子[C_nMIM]⁺中的n越大,可促进酶活性的离子液体适宜含量越低;Br^-,[BF₄]^-系列离子液体的浓度超过CMC时则抑制酶活;阴离子对酶活性的最大促进作用顺序为Br^->Cl^->[BF₄]^->[PF₆]^-.离子液体对酶活性的影响随体系pH和温度的不同而改变,在最适离子液体浓度时的最适pH均为7.000.在pH 7.000,30 ^oC以及[C₈MIM]Br离子液体浓度为47.6 mmol/L的最佳条件下,最高相对酶活力和比活力分别达到1734%和54.4 U/mg protein.     

配合物(BenzMeIm)2[PtCl4]的合成与表征

通过离子液体氯化1-苄基-3-甲基咪唑（BenzMeIm-Cl）与PtCl₂的反应,合成了配合物（BenzMeIm）₂[PtCl₄],并用元素分析、红外光谱、紫外-可见光谱、¹H NMR、¹³C NMR和单晶X射线衍射对其进行了表征。单晶X射线分析表明,配合物结构属于P2₁/c空间群,晶胞参数和结构解析参数为：a=0.981 80（5）nm,b=0.861 47（3）nm,c=0.144 332（7）nm,β=92.480（2）°,V=121.96（1）nm³,R₁=0.014 4,wR₂=0.038 8。     

配合物(BenzMeIm)2[PtCl4]的合成与表征

通过离子液体氯化1-苄基-3-甲基咪唑（BenzMeIm-Cl）与PtCl₂的反应,合成了配合物（BenzMeIm）₂[PtCl₄],并用元素分析、红外光谱、紫外-可见光谱、¹H NMR、¹³C NMR和单晶X射线衍射对其进行了表征。单晶X射线分析表明,配合物结构属于P2₁/c空间群,晶胞参数和结构解析参数为：a=0.981 80（5）nm,b=0.861 47（3）nm,c=0.144 332（7）nm,β=92.480（2）°,V=121.96（1）nm³,R₁=0.014 4,wR₂=0.038 8。     

两个基于呋喃-3-酮配体的钯(Ⅱ)化合物的合成、晶体结构和光谱性质

合成了2个钯（Ⅱ）化合物Pd（L¹）₂（1）和Pd（L²）₂（2）,（L¹=（Z）-4-（（对甲苯胺基）亚甲基）-2,2,5,5-四甲基二氢呋喃-3（2H）-酮,L²=（Z）-4-（（邻甲苯胺基）亚甲基）-2,2,5,5-四甲基二氢呋喃-3（2H）-酮）,并利用元素分析,红外光谱,核磁共振氢谱,紫外光谱和X射线单晶衍射等手段对其结构进行了表征。X射线单晶衍射表明,化合物1和2中包含多种弱相互作用。在化合物1中,呋喃环上氧原子和苯环上的甲基氢原子之间形成氢键,氢键桥联分子形成了一条平行于c轴方向的一维链结构,一维链之间通过C-H…H-C和C-H…C弱相互作用形成了三维超分子结构。在化合物2中,分子之间通过C-H…H-C和C-H…C弱相互作用形成了一个二维层状结构。     

Efficient Extractive Desulfurization of Fuel Oils Using N‐Pyrrolidone/Alkylphosphate‐Based Ionic Liquids

Four BrØsted acid ionic liquids (ILS) [MMP][DMP], [MEP][DEP], [HMP][DMP] and [HEP][DEP] were synthesized and used as extractants for desulfurization of aromatic sulfur compounds in model oil. The mutual solubility of four ILs were investigated. The extraction equilibrium of four ILs could be reached in as soon as 5 min and the extraction capability followed the order [MMP][DMP]>[MEP][DEP]>[HEP][DEP]>[HMP][DMP]. The S extraction showed the highest efficiency under the conditions of 30°C, 30 min and 1:1 (V/V) IL:oil. Under the optimal condition, 70.9% of thiophene (TS), 76.9% of benzothiophene (BT) and 87.5% of dibenzothiophene (DBT) in n‐octane could be efficiently removed by [MMP][DMP]. The multiple extraction and regeneration performance of [MMP][DMP] for TS was also investigated and the results were satisfying. These results suggest that [MMP][DMP] has the best extraction capability and can serve as a promising solvent for extractive desulfurization of fuel oils.     

Determination of ethanol in ionic liquids using headspace solid-phase microextraction–gas chromatography

The application of ionic liquids (ILs) as nonderivatizing solvents for the pretreatment and regeneration of cellulose is a growing area of research. Here we report the development of a rapid and simple method for the determination of residual ethanol content in two hydrophilic ILs, 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate. The method utilizes headspace solid-phase microextraction coupled with gas chromatography at elevated extraction temperatures, resulting in rapid equilibration times. The effect of IL water content on the ethanol extraction efficiency is presented. Recovery experiments carried out in real samples gave recoveries ranging from 96.8 to 98.2%.     

离子液体的结构及其汽油萃取脱硫性能

用不同金属氯化物与氯代甲基咪唑合成离子液体,采用快原子轰击谱测定了这些离子液体的结构,并评价了这些离子液体对汽油萃取脱硫的能力.实验结果表明,由CuCl合成的离子液体中存在稳定的CuCl-2 ,Cu2Cl-3 和Cu3Cl-4 阴离子.这些阴离子可能通过Cu(I)与S的π络合作用而使离子液体具有较高的萃取脱硫效率.经六次萃取后,汽油中的硫含量可以从 650 μg·g-1降至 20~30μg·g-1.     

Extractive desulfurization of fuel oil with metal-based ionic liquids

Several metal-based ionic liquids (ILs) were synthesized and used as extractants for the desulfurization of dibenzothiophene (DBT) in simulated fuel oil. The effects of several anion and metal ions, n(ILs)/n(metal) as mole ratio, V_IL/V_oil and extractive times on the removal ratio of DBT were investigated in detail. The results showed that [BMIM]HSO₄/FeCl₃(BMIM was short for 1-butyl-3-methyl imidazole) was superior to the other ILs for the extractive desulfurization. A total of 100% of DBT was removed at room temperature in 5 min with V_[BMIM]HSO₄=FeCl₃=V_oil=1:1. The extractive activity of [BMIM]HSO₄/FeCl₃ IL did not change almost after five runs. Extractive desulfurization of different sulfur compounds and commercial diesel fuel oil were also examined. The removal ratios of the sulfur compounds as the reaction substrates were all over 90% and the sulfur content of commercial diesel oil decreased to 120 ppm from 12,400 ppm.     

酸性离子液体萃取/催化二苯并噻吩氧化脱硫反应的优化

ö以Brönsted酸性离子液体N-甲基-2-吡咯烷酮磷酸二氢盐(\[Hnmp\]H₂PO₄)为萃取剂和催化剂,双氧水为氧化剂,二苯并噻吩(DBT)溶于正辛烷为模型油,利用正交实验法优化了DBT氧化脱硫反应工艺。所优化的反应条件为：反应温度60℃,模型油与离子液体体积比为1∶1,氧/硫摩尔比为16, 氧化时间5h;在此条件下模型油脱硫率达99.8%,实际柴油脱硫率为64.3%。由正交实验极差可知,各因素对DBT脱硫率影响的大小依次为：反应温度＞反应时间＞氧/硫摩尔比＞剂油比;离子液体循环利用6次,脱硫率下降不明显。     

Extractive Desulfurization of Liquid Fuel using Modified Pyrollidinium and Phosphonium Based Ionic Liquid Solvents

In the pursuit of better solvents for use in the extractive desulfurization (EDS) of liquid fuel, the pyrollidinium and phosphonium based ionic liquids (ILs) have been improved by combining them with selected molecular compound modifiers. The modifiers, which are imidazole, poly(ethylene) glycol (PEG 200) and sulfolane were selected to induce previously nonexistent mechanisms in the presence of refractory sulfur compounds. The addition of PEG 200 and sulfolane were observed to have a more positive impact on the performance of the ILs than the addition of imidazole under the same conditions. This provides further support for the idea that π–π interaction may not be the predominant interactions for the ILs that are the highly effective in EDS. Using the sulfolane modified tetrabutylphosphonium methanesulfonate [P₄₄₄₄][MeSO₃], up to 81% dibenzothiophene (DBT) removal was recorded at a temperature of 30 °C and solvent-to-mass ratio of 1:1 and after a 30 min mixing time.     

Theoretical study of interactions between 1-alkyl-3-methyimidazolium tetrafluoroborate and dibenzothiophene: DFT,NBO, and AIM analysis

Density functional theory is employed to study the interaction energies between dibenzothiophene (DBT) and 1-alkyl-3-methylimidazolium tetrafluoroborate ([C _n mim]⁺[BF₄]^?). The structures of DBT, 1-ethyl-3-methylimidazolium tetrafluoroborate ([C₂mim]⁺[BF₄]^?), 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim]+[BF₄]?), 1-hexyl-3-methylimidazolium tetrafluoroborate ([C₆mim]⁺[BF₄]^?), 1-octyl-3-methylimidazolium tetrafluoroborate ([C₈mim]⁺[BF₄]^?), [C₂mim]⁺[BF₄]^?–DBT, [C₄mim]⁺[BF₄]^?–DBT, [C₆mim]⁺[BF₄]^?–DBT and [C₈mim]⁺[BF₄]^?–DBT systems are optimized systematically at the B3LYP/6-31G(d,p) level, and the most stable geometries are obtained by NBO and AIM analyses. The results indicate that DBT and imidazolium rings of ionic liquids are parallel to each other. It is found that the [BF₄]^? anion prefers to be located close to a C1–H9 proton ring in the vicinity of the imidazolium ring and the most stable gas-phase structure of [C _n mim]⁺[BF₄]^? has four hydrogen bonds between [C _n mim]+ and [BF₄]?. There are hydrogen bonding interactions, π–π and C–H–π interactions between [C₈mim]⁺[BF₄]^? and DBT, which is confirmed by NBO and AIM analyses. The calculated interaction energies for the studied ionic liquids can be used to interpret a better extracting ability of [C₈mim]⁺[BF₄]^? to remove DBT, due to stronger interactions between [C₈mim]⁺[BF₄]^? and DBT, in agreement with the experimental results of dibenzothiophene extraction by [C _n mim]⁺[BF₄]^?.     

模拟油品氧化脱硫及反应动力学研究

在H₂O₂/WO₃/ZrO₂氧化体系中对以甲苯为溶剂、二苯并噻吩(DBT)为模型含硫化合物的模拟油品(硫的质量分数为1540×10^-6)进行了氧化脱硫研究,考察了反应温度、反应时间、氧化剂加入量、催化剂用量对DBT转化率的影响。实验结果表明,在反应温度50℃,反应时间90min,氧化剂加入量油/H₂O₂的体积比为20∶1和催化剂用量0.02g/mL的适宜氧化脱硫条件下,96%以上的DBT氧化为容易分离脱除的二苯并噻吩砜(DBTOs);同时研究了DBT氧化反应动力学,得知DBT氧化反应为一级反应,表观活化能E_a为55.37kJ/mol,指前因子A为3.35×10⁷min^-1。     

Partition of horseradish peroxidase with maintained activity in aqueous biphasic system based on ionic liquid

Enzyme activity and partition behavior in aqueous biphasic systems (ABSs) consisting of ionic liquid (IL) and salt (IL-ABSs) were investigated to increase our understanding of IL-ABSs and shed light on their application potential as enzyme extraction system. With horseradish peroxidase (HRP) as the model enzyme, several effects of alkylimidazolium chloride-K₂HPO₄ ABSs on activity and partition behavior of enzyme were studied including alkyl chain length of ILs and concentrations of each component. High lyotropic ILs (1-butyl-3-methylimidazolium and 1-ethyl-3-methylimidazolium chloride) and adequate water content (>40%) were both essential for the activity maintenance of HRP in IL-ABS. 1-Butyl-3-methylimidazolium chloride ([C₄mim]Cl) was found to be an appropriate IL for phase forming and HRP activity retaining. After optimization of phase condition, about 80% HRP amount was distributed in the IL-rich upper phase, and greater than 90% enzyme activity was obtained. Moreover, compared with the commonly used polymer-based ABSs, this [C₄mim]Cl-ABS has a much lower viscosity, which is very beneficial to the experimental operation. Therefore, the tested IL-ABS could be considered as a potential enzyme extraction system.     

The physicochemical properties of some imidazolium-based ionic liquids and their binary mixtures

The density, viscosity and conductivity of ionic liquids (ILs), 1-octyl-3-methylimidazolium tetrafluoroborate ([omim][BF4]), 1-octyl-3-methylimidazolium chloride ([omim][Cl]), 1-hexyl-3-methylimidazolium tetrafluoroborate ([hmim] BF4]), 1-hexyl- 3-methylimidazolium chloride ([hmim][Cl]), 1-hexyl-3-methylimidazolium hexafluorophosphate ([hmim][PF6]), and the [omim][BF4] + [omim][Cl], [hmim][BF4] + [hmim][Cl], and [hmim][PF6] + [hmim][Cl] binary mixtures were studied at dif- ferent temperatures. It was demonstrated that the densities of both the neat ILs and their mixtures varied linearly with temper- ature. The density sensitivity of a binary mixture is between those of the two components. The excess molar volumes (VE) of [hmim][BF4] + [hmim][Cl] and [hmim][PF6] + [hmim][Cl] mixtures are positive in the whole composition range. For [omim][BF4] + [omim][Cl], the VE is also positive in the [omim][Cl]-rich region, but is negative in the [omim][BF4]-rich re- gion. The viscosity or conductivity of a mixture is in the intermediate of those of the two neat ILs. For all the neat ILs and the binary mixtures studied, the order of conductivity is opposite to that of the viscosity. The Vogel-Tammann-Fulcher (VTF) equations can be used to fit the viscosity and conductivity of all the neat ILs and the binary mixtures. The neat ILs and their mixtures obey the Fractional Walden Rule very well, and the values of the Walden slopes are all smaller than unit, indicating obvious ion associations in the neat ILs and the binary mixtures.