功能化离子液体的制备及其在合成中的应用

功能化离子液体;手性离子液体;酸性离子液体     

二维离子色谱法同时测定环境水样中的碘离子、硫氰酸根和高氯酸根

建立了二维离子色谱法同时测定环境水样中的碘离子、硫氰酸根离子和高氯酸根离子的方法。先采用常规阴离子色谱柱(IonPac AS16, 250 mm×4 mm)将水样中的碘离子、硫氰酸根离子和高氯酸根离子与干扰离子进行分离。样品溶液通过抑制器后,将含有碘离子、硫氰酸根离子和高氯酸根离子的淋洗液导入富集柱(MAC-200, 80 mm×0.75 mm),再通过毛细管阴离子色谱柱(IonPac AS20 Capillary, 250 mm×0.4 mm)进行分离和定量分析。方法的线性范围为0.05～100 μg/L,相关系数达到0.9999,检出限为0.02～0.05 μg/L。样品中碘离子、硫氰酸根离子和高氯酸根离子的加标回收率在85.1%～100.1%之间,回收率的相对标准偏差(RSD)(n=6)在1.7%～4.9%之间。该法试剂用量小,灵敏度比常规离子色谱提高30～40倍,同时去除了样液中的高浓度基体杂质,适用于水样中低含量碘离子、硫氰酸根离子和高氯酸根离子的检测。     

漂移管工作温度对离子迁移率谱的影响

离子迁移率、反应物离子的种类和产量与漂移管工作温度有很大的关系。本研究在不同温度下进行了离子迁移率实验,结果表明,离子迁移率随温度的升高而增大,而提高工作温度可以减少水分子对产物离子的影响,有利于改善系统检测的分辨率;选择合适漂移管工作温度,能有效地增加反应物离子的产量,从而提高系统检测的灵敏度和选择性。     

新型单离子聚醚/聚氨酯固体电解质制备及其离子导电性

磺化聚醚;离子电导率;聚合物;新型单离子聚醚/聚氨酯固体电解质制备及其离子导电性     

LiNO3在DMF中的离子溶剂化和离子缔合的红外光谱

LiNO3在DMF中的离子溶剂化和离子缔合的红外光谱;硝酸锂;N;N-二甲基甲酰胺;离子溶剂化;离子缔合;红外光谱法     

离子液体在制备金属氧化物纳米材料中的应用

总结了近年来在离子液体中制备金属氧化物纳米材料的新方法以及离子液体在金属氧化物纳米材料制备方面的应用及发展趋势.目前,对于制备纳米金属氧化物,离子液体主要是作为电解液、表面活性剂;其未来的发展趋势是离子热合成和集模板-溶剂-反应物于一身的离子液体反应.     

离子交联聚氯乙烯的结构与性能

由氯乙烯/丙烯酸悬浮共聚合成了不同羧基含量的PVC树脂,采用溶液反应和熔融加工法制备离子交联PVC,对其结构和性能进行了研究.结果表明,共聚物中羧基主要以二聚体形式存在,用金属离子中和能形成部分络合结构;用Ca²⁺、Mg²⁺离子络合的羧基含量较高的VC/AA共聚物存在离子对聚集态结构;离子对含量、金属离子种类和增塑剂浓度影响离子聚集相的比例和稳定性,离子聚集具有热可逆性;离子交联使PVC的T_g、熔体粘度和回弹性提高.     

离子液体与绿色化学：为了今天还是为了未来？

离子液体因绿色化学的兴起而成名。本文结合作者自己8年来的研究工作评述了离子液体特别是在化学合成、化学反应领域的最新进展。主要分4个方面：离子液体改变了载体/模版的概念;离子液体研究促进了液相反应的研究;离子液体推动了相分离技术的进步;离子液体推动了绿色化学的发展。     

1-烷基-3-甲基咪唑l-乳酸盐的合成及其物理性质

离子液体;手性离子液体;烷基甲基咪唑l-乳酸盐     

离子液体中制备无机材料

离子液体作为潜在的“绿色”溶剂,具有许多传统溶剂无法比拟的优异性能,在有机合成、催化、液液分离和萃取等领域引起了广泛的研究。而在离子液体领域无机材料的制备是一个较新的发展分支,现已利用其合成出多种具有独特结构和性能的无机材料。本文就离子液体在无机材料制备方面的应用及发展趋势进行了综述。目前,对于制备无机材料,离子液体主要是作为电解液、表面活性剂或溶剂,本文介绍了其在应用中的优缺点,并指出该领域未来的发展趋势是离子热合成和集模板-溶剂-反应物于一身的离子液体反应。     

阴离子对RhCl（CO）（TPPTS）2催化1—己烯氢甲酰化反应的影响

在烯烃氢甲酰化反应两相催化体系中,为提高催化剂活性及选择性,有采用外加无机盐的报道［１～３］．从这些文献可以看出,某些无机盐在反应中起到催化助剂的作用．我们曾经研究了硫酸钠及其它金属硫酸盐中的阳离子对反应的影响［４,５］．在引入这些阳离子的同时,还有...     

ZrO2负载碳纳米管吸附去除水中氟的研究

以ZrO2负载多壁碳纳米管(ZrO2-MWCT)为吸附剂,系统研究了其对水中F-的吸附、脱附性能。结果表明,F-在ZrO2-MWCT吸附剂上的吸附等温线可以用Freundlich方程模拟,吸附动力学符合拟二级动力学方程,吸附速率随着F-初始浓度的提高而减低。当pH为4~5时,F-在ZrO2-MWCT吸附剂上的吸附量最大。水中阴离子的存在降低ZrO2-MWCT对F-的吸附量,不同阴离子对F-影响的大小顺序为:CO32->SO42->Cl->NO3-。吸附饱和的ZrO2-MWCT可用0.1mol/L的NaOH脱附再生,经4次再生后,其吸附量仍为14.55mg/g。     

Keggin杂多阴离子电子结构和物化性质与中心原子的 关系

使用密度泛函理论中的离散变分方法(DFT-DVM),以(XMo12O40)^n-(X=B,Al,Si,Ge,P,As,S)为例计算了七个Keggin杂多阴离子的电子结构,讨论了中心原子对Keggin阴离子的电子结构、稳定性、氧化还原性和酸性关系。根据计算结果,给出稳定性、氧化还原性强弱顺序,计算给出结果与实验一致。     

Influence of terminal substituents on the halide anion binding of foldamer-based receptors

Foldamers 1–4 incorporating different terminal substituents have been designed and synthesized for binding halide anions.~1H NMR titration experiments carried out in DMSO-d_6/CDCl_3(15/85, v/v)demonstrated that the short oligo (aryltriazole)s backbone 1 could not bind halide anions unless that amide H-bond donors were incorporated at the termini of the oligomer. Terminal substituents on oligo(aryltriazoleamide)s foldamers 2–4 display a considerable influence on the binding affinities of the foldamers for halide anions. Large steric hindrance of the terminal substituents was found to be unfavorable for binding halide anions, but aromatic π-π interactions between two terminal substituents are capable of stabilizing the conformation of foldamers thus giving rise to an enhancement in the binding strengths. However, the terminal substituents were found to hardly affect the binding selectivity in the studied cases.     

Electron photodetachment from aqueous anions. 3. Dynamics of Geminate pairs derived from photoexcitation of mono- vs polyatomic anions

Photostimulated electron detachment from aqueous inorganic anions is the simplest example of solvent-mediated electron transfer reaction. As such, this photoreaction became the subject of many ultrafast studies. Most of these studied focused on the behavior of halide anions, in particular, iodide, that is readily accessible in the UV. In this study, we contrast the behavior of these halide anions with that of small polyatomic anions, such as pseudohalide anions (e.g., HS(-)) and common polyvalent anions (e.g., SO(3)(2-)). Geminate recombination dynamics of hydrated electrons generated by 200 nm photoexcitation of aqueous anions (I(-), Br(-), OH(-), HS(-), CNS(-), CO(3)(2-), SO(3)(2-), and Fe(CN)(6)(4-)) have been studied. Prompt quantum yields for the formation of solvated, thermalized electrons and quantum yields for free electrons were determined. Pump-probe kinetics for 200 nm photoexcitation were compared with kinetics obtained at lower photoexcitation energy (225 or 242 nm) for the same anions, where possible. Free diffusion and mean force potential models of geminate recombination dynamics were used to analyze these kinetics. These analyses suggest that for polyatomic anions (including all polyvalent anions studied) the initial electron distribution has a broad component, even at relatively low photoexcitation energy. There seems to be no well-defined threshold energy below which the broadening of this electron distribution does not occur, as is the case for halide anions. The constancy of (near-unity) prompt quantum yields vs the excitation energy as the latter is scanned across the lowest charge-transfer-to-solvent band of the anion is observed for halide anions but not for other anions: the prompt quantum yields are considerably less than unity and depend strongly on the excitation energy. Our study suggests that halide anions are in the class of their own; electron photodetachment from polyatomic, especially polyvalent, anions exhibits qualitatively different behavior.     

杯[4]二吡咯与卤素阴离子相互作用的密度泛函理论研究

采用密度泛函B3LYP方法, 在6\|31G*/LANL2DZ水平上对杯[4]二吡咯主体分子及其与卤素阴离子形成的复合物进行研究.  结果表明, 杯[4]二吡咯可与卤素阴离子相互作用形成具有较高对称性的复合物, 其8个吡咯NH基团上的H原子均可以和卤素阴离子形成氢键; 杯[4]二吡咯与卤素阴离子结合能力大小的顺序为F- >Cl- >Br- > I-.  振动光谱、 电荷分布以及前线轨道计算结果表明, 杯[4]二吡咯与卤素阴离子相互作用的本质为氢键, 经BSSE校正的结合能与电荷转移程度、 N-H键键长和N-H伸缩振动频率变化呈线性关系.      

Aromaticity of Heterofullerenes C18BxNy (x+y=2) and Their Molecular Ions

The aromaticity of all possible substituted fullerene isomers of C18N2, C18B2, C18BN, and their molecularions which originate from the C20 (Ih) cage were studied by the topological resonance energy (TRE) and the percentage topological resonance energy methods. The relationship between the aromaticity of C18BxNy isomers and the sites where the heteroatoms dope at the C20 (Ih) cage is discussed. Calculation results show that at the neutral and cationic states all the isomers are predicted to be antiaromatic with negative TREs, but their polyvalent anions are predicted to be aromatic with positive TREs. The most stable isomer is formed by heteroatom doping at the 1,11-sites in C18N2, C18B2, and C18BN. Heterofullerenes are more aromatic than C20. The stability order in the neutral states is C18N2>C18BN>C18B2>C20. The stability order in closed-shell is C18B2 8->C20 6->C18BN6->C18N2 4-. This predicts theoretically that their polyvalent anions have high aromaticity.     

一种三足型比色传感器对阴离子的颜色响应

A thiourea-based tripodal colorimetric anion sensor was synthesized. Its binding abilities with AcO^- and halide anions in DMSO were studied by UV-Vis spectra. The sensor showed different color responses to these anions. The association constants and different stoichiometries were deduced by nonlinear least-square curve fitting or linear fitting.     

Visible-Light-Switchable Tellurium-Based Chalcogen Bonding: Photocontrolled Anion Binding and Anion Abstraction Catalysis

Exploring new noncovalent bonding motifs with reversibly tunable binding affinity is of fundamental importance in manipulating the properties and functions of supramolecular self-assembly systems and materials. Herein, for the first time, we demonstrate a unique visible-light-switchable telluro-triazole/triazolium-based chalcogen bonding (ChB) system in which the Te moieties are connected by azobenzene cores. The binding strengths between these azo-derived ChB receptors and the halide anions (Cl⁻, Br⁻) could be reversibly regulated upon irradiation by visible light of different wavelengths. The cis-bidentate ChB receptors exhibit enhanced halide anion binding ability compared to the trans-monodentate receptors. In particular, the telluro-triazolium-based ChB receptor can achieve both high and significantly photoswitchable binding affinities for halide anions, which enable it to serve as an efficient photocontrolled organocatalyst for ChB-assisted halide abstraction in a Friedel–Crafts alkylation benchmark reaction.     

Structure and conformation properties of 1-alkyl-3-methylimidazolium halide ionic liquids: a density-functional theory study

The structures and conformational properties of 1-alkyl-3-methylimidazolium halide ionic liquids have been studied with a Becke's 3 Parameter functional method. The interaction mechanisms between the cation and the anion in 1-ethyl-3-methylimidazolium (Emim+) halide and 1-butyl-3-methylimidazolium (Bmim+) halide ionic liquids were investigated using 6-31G*, 6-31++G**, and 6-311++G** basis sets. Forty structures of different ion pairs were optimized and geometrical parameters of them have been discussed in details. Halide ions (Cl- or Br-) have been gradually placed in different regions around imidazolium cation and the interaction energies between the anion and the cation have been calculated. Theoretical results indicate that there are four activity regions in the vicinity of the imidazolium cations, in these regions the imidazolium cations and the halide anions formed stable ion pairs. Imidazolium cations can form hydrogen bond interactions with one, two or three but no more than three nearest halide anions. The halide ions are situated in hydrogen bond positions rather than at random.