The Synthesis of Anatase TiO2 Nanoparticles by Solvothermal Method using Ionic Liquid as Additive

The solvothermal reactions of Ti(OiPr)₄ in alcohol using ionic liquid as additive were investigated. In the presence of [BMIM][Cl], [BMIM][Br], [BMIM][NTf₂], [BMIM][SO₃Me], [BMIM][SO₄Me], or [BMIM][OTf] (BMIM = 1‐Butyl‐3‐methylimidazolium), pure anatase nanoparticles were obtained. The controlled hydrolysis of Ti(OiPr)₄ in the presence of ionic liquids to form titanium oxo clusters plays a key role in the formation of anatase nanostructures, and ionic liquids can be repeatedly used to synthesise anatase nanoparticles. However, in the presence of [BMIM][PF₆], [BMIM]₂[Ti(OH)₆] was obtained by an anion exchange reaction.     

Synthesis and formation mechanism of nanoneedles and nanorods of manganese oxide octahedral molecular sieve using an ionic liquid

Single-crystalline cryptomelane-type manganese oxide octahedral molecular sieve (OMS-2) nanoneedles and nanorods were prepared by a solution-phase approach in the presence of an ionic liquid 1-n-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4). [BMIM]BF4 can act as a cosolvent, structure-directing agent, and reducing reagent in the reaction system. Based on the redox reaction of MnCl2 and KMnO4 in the mixed solvents of water and [BMIM]BF4, the formation of OMS-2 nanoneedles followed the rolling mechanism with lamellae as an intermediate. However, the direct reaction of KMnO4 with [BMIM]BF4 resulted in the formation of OMS-2 nanorods with diameters as small as 3-6 nm. The formation mechanism of OMS-2 nanostructures was discussed.     

Structures of ionic liquids with different anions studied by infrared vibration spectroscopy

We investigated the structures of ionic liquids (1-butyl-3-methylimidazolium iodide [BMIM][I] and 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4]) and their aqueous mixtures using attenuated total reflection (ATR) infrared absorption and Raman spectroscopy. The ATR spectrum in the CHx (x = 1, 2, 3) vibration region from 2800 to 3200 cm-1 was very different between [BMIM][BF4] and [BMIM][I] even though all the spectral features in this region were from the butyl chain and the imidazolium ring of the same cation. The spectrum did not change appreciably irrespective of the water concentration for [BMIM][BF4], whereas the spectrum from [BMIM][I] showed significant changes as the water concentration was increased, especially in CH-vibration modes from the imidazolium ring. For very diluted solutions both aqueous mixtures of [BMIM][I] and [BMIM][BF4] showed very similar spectra. Mixing of [BMIM][I] with heavy water (D2O) facilitated the isotopic exchange of the proton attached to the most acidic carbon of the imidazolium ring into deuterium from D2O, whereas even prolonged exposure to D2O did not induce any isotopic exchange for [BMIM][BF4]. Raman spectra around 600 cm(-1) indicative of the butyl chain conformation also changed differently as the water concentration was increased between [BMIM][I] and [BMIM][BF4]. These differences are considered to come from the variation in the position of the anion, where I- is expected to be closer to the C(2) hydrogen of the imidazolium cation and interacting more specifically as compared to BF(4-).     

Microwave-assisted synthesis of sulfide M2S3 (m = Bi, Sb) nanorods using an ionic liquid

Single-crystalline Bi(2)S(3) and Sb(2)S(3) nanorods have been successfully synthesized by the microwave-assisted ionic liquid method. The starting reagents were Bi(2)O(3) or Sb(2)O(3), HCl, Na(2)S(2)O(3), and ethylene glycol (EG) or ethanolamine, and the ionic liquid used was 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF(4)]). Our experiments showed that the ionic liquid played an important role in the morphology of M(2)S(3) (M = Bi, Sb). Single-crystalline Bi(2)S(3) nanorods could be prepared in the presence of [BMIM][BF(4)]. However, urchinlike Bi(2)S(3) structures consisting of nanorods were formed without using [BMIM][BF(4)]. Single-crystalline Sb(2)S(3) nanorods were obtained in the presence of [BMIM][BF(4)]. However, single-crystalline Sb(2)S(3) nanosheets could be prepared in the absence of [BMIM][BF(4)]. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and electron diffraction (ED).     

Determination of an acidic scale in room temperature ionic liquids

The acidity scale of different Br?nsted acids in ionic liquids such as [BMIM][NTf2], [BMIM][BF4], and [BMMIM][BF4] has been investigated by determination of Hammett functions, using a spectrophotometric indicator method. This scale should permit one to correlate the acidity strength of ionic liquid systems with their ability to achieve acid-catalyzed reactions.     

在离子液/水体系中超声合成MoO_3纳米棒及其表征(英文)

采用超声波的方法在离子液(1-丁基-3-甲基氯代咪唑盐离子液,[BMIM]Cl)中合成了直径分布在80~150 nm的MoO3纳米棒.采用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、场发射扫描电子显微镜(FESEM)、高分辨透射电子显微镜(HRTEM)和选区电子衍射(SAED)对所合成材料的微观结构和形貌进行了表征.此外,考察了反应时间、加入[BMIM]Cl的量以及其它咪唑基离子液对产物的影响并提出了可能的反应机理.最后对在不同温度煅烧下所得的α-MoO的甲烷催化燃烧活性进行了表征.     

A single-source route to CdS nanorods

We report the preparation of CdS nanorods using a thiosemicarbazide complex of cadmium [Cd(NH2CSNHNH2)2Cl2]. The precursor was decomposed in tri-n-octylphosphine oxide (TOPO) at 280 degrees C to give TOPO capped CdS nanoparticles; nano-dimensional rods of the material are clearly visible in transmission electron microscopy (TEM); the particles have been further characterised by X-ray diffraction (XRD) and selected area electron diffraction (SAED) and optical measurements.     

Synthesis of cyano-bridged magnetic nanoparticles using room-temperature ionic liquids

A principally new exploit of ionic liquids as an alternative reaction medium in the synthesis of cyano-bridged coordination-polymer nanoparticles is reported. Stable colloid solutions containing nanoparticles of cyano-bridged molecule-based magnets, M)[Fe(CN)6]2/[RMIM][BF4] (M2+=Ni, Cu, Co) and Fe4[Fe(CN)6]3/[RMIM][BF4] (R=1-butyl (BMIM), 1-decyl (DMIM)), were prepared in the corresponding 1-R-3-methylimidazolium tetrafluoroborate [RMIM][BF4], which acts as both a stabilising agent and a solvent. By varying the length of the N-alkyl chain on the imidazolium cation of [RMIM]+ and the temperature, the growing process can be controlled to produce nanoparticles of different sizes. By studying the magnetic properties of frozen colloids it is shown that the relaxation of magnetisation is strongly influenced by interparticle interactions, which leads to the appearance of spin-glass-like dynamics in these systems.     

Can the absence of solvation of neutral reagents by ionic liquids be responsible for the high reactivity in base-assisted intramolecular nucleophilic substitutions in these solvents?

[reaction: see text] The kinetics of the rearrangement of the Z-phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole (1a) into the relevant 4-benzoylamino-2,5-diphenyl-1,2,3-triazole (2a) induced by amines have been studied in two room-temperature ionic liquids (IL-1, [BMIM][BF4] and IL-2, [BMIM][PF6]). The data collected show that the reaction occurs faster in ionic liquids than in other conventional solvents previously studied (both polar or apolar, protic or aprotic). Presumably, this could depend on their peculiar ability to minimize the strong substrate-solvent, amine-solvent and amine-amine interactions occurring in conventional solvents.     

Growth of sputter-deposited gold nanoparticles in ionic liquids

The growth of gold nanoparticles (NPs) synthesized by sputter deposition on an ionic liquid surface is studied in situ in the bulk phase of the ionic liquids (ILs) 1-butyl-3-methylimidazolium dicyanamide [C(1)C(4)Im][N(CN)(2)], 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide [C(1)C(4)Im][Tf(2)N], 1-butyl-3-methylimidazolium tetrafluoroborate [C(1)C(4)Im][BF(4)], 1-butyl-3-methylimidazolium hexafluorophosphate [C(1)C(4)Im][PF(6)] and 1-butyl-3-methylimidazolium triflate [C(1)C(4)Im][TfO]. It is found that primary nanoparticles with a diameter smaller than 2.5 nm are present in the sample immediately after sputtering. Growth of these primary particles proceeds after the end of the sputtering process and stops when the nanoparticles reach a certain size. Depending on the viscosity of the ionic liquid this growth process can proceed several hours to several days. The growth speed is fastest for the least viscous ionic liquid and follows the trend [C(1)C(4)Im][N(CN)(2)] > [C(1)C(4)Im][Tf(2)N] > [C(1)C(4)Im][TfO] > [C(1)C(4)Im][BF(4)] > [C(1)C(4)Im][PF(6)]. It is also found that a higher concentration of sputtered gold results in faster growth of the gold nanoparticles. A discussion on the growth mechanism of sputtered gold NPs is included.     

Sum frequency generation spectroscopy of dicyanamide based room-temperature ionic liquids. Orientation of the cation and the anion at the gas-liquid interface

The orientation of the cation and the anion of room-temperature ionic liquids using sum frequency generation vibrational spectroscopy is reported. The ionic liquids are based on butyl-methyl imidazolium [BMIM]+ and hexyl-tributyl ammonium [N6444]+ together with dicyanamide [DCA]- as the anion. The tilt angle of the C3 axis of the methyl group from the alkyl chain in the cations was found to vary from 52 degrees to 80 degrees as a function of the distribution width sigma (which ranges from 0 degrees to 30 degrees with respect to the surface normal) for [BMIM][DCA] and similarly for [N6444][DCA]. The orientation of the C2 axis in the dicyanamide anion as a function of the twist angle phi, varied between 46 degrees and 90 degrees for [BMIM][DCA] and from 53 degrees to 90 degrees for [N6444][DCA]. These results suggest the presence of both ionic species at the gas-liquid interface and help describe the behavior of a simple inorganic anion at the surface.     

Facile in situ synthesis of nanofluids based on ionic liquids and copper oxide clusters and nanoparticles

Two stable nanofluids comprising of mixed valent copper(I,II) oxide clusters (<1 nm) suspended in 1-butyl-3-methylimidazolium acetate, [C(4)mim][OAc], and copper(II) oxide nanoparticles (<50 nm) suspended in trioctyl(dodecyl)phosphonium acetate, [P(8 8 8 12)][OAc], were synthesised in a facile one-pot reaction from solutions of copper(II) acetate hydrate in the corresponding ionic liquids. Formation of the nanostructures was studied using (13)C NMR spectroscopy and differential scanning calorimetry (DSC). From a solution of Cu(OAc)(2) in 1-ethyl-3-methylimidazolium acetate, [C(2)mim][OAc], crystals were obtained that revealed the structure of [C(2)mim][Cu(3)(OAc)(5)(OH)(2)(H(2)O)]·H(2)O, indicating the formation of copper hydroxo-clusters in the course of the reaction. Synthesised nanostructures were studied using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Physical properties of the prepared IL-nanofluids were examined using IR and UV-VIS spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and densitometry.     

Effect of the conditions of anodizing on the morphology of nanotitania

The effect the current density, treatment time, surface pretreatment, and electrolyte composition have on the morphology of titania obtained via electrochemical treatment in such ionic liquids (ILs) as 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BMIM][NTf₂] and 1-butyl-3-methylimidazolium chloride [BMIM]Cl is studied. The anodic formation of titania nanostructures in the form of nanotubes or nanorods is found to occur in times of up to 100 s. The role of water in the formation of these titania nanostructures is shown. Pretreatment has no effect on the morphology of the formed oxide. The formation of products that are poorly soluble in ILs (e.g., hydrated oxides) results in the emergence of a layer partially covering the open parts of nanotubes, preventing their further growth.     

Ionic liquid buffers: a new class of chemicals with potential for controlling pH in non-aqueous media

Ionic liquids with buffering characteristics, synthesized by the reaction of [RMIM]OH base moieties with phthalic and tartaric acid, respectively, are potential reagents for controlling pH in non-aqueous media; remarkable [Base]/[Acid] molar ratio dependence of the catalytic activities has been observed in the hydrogenation of olefins with [RuCl2(PPh3)3] complex in DMF and [BMIM][BF4].     

利用牛血清蛋白合成CdS纳米棒和网状纳米线

采用简单易控、对环境友好的矿化方法, 利用牛血清蛋白(BSA)做模板, 通过Cd2+与硫代乙酰胺(TAA)反应制备了形貌均一的CdS纳米棒和网状纳米线. 分别采用透射电子显微镜(TEM)、X射线能谱(EDS)、X射线衍射(XRD)、荧光(PL)发射谱和导电原子力显微镜(C-AFM)等方法对不同实验温度下制备的CdS样品的结构形貌、成分组成和光学性质及微区电子传输行为进行了表征. 结果表明: 在实验反应温度为20 ℃时, 得到的产物为单分散性好的CdS 纳米棒, 长度为250 nm, 直径为30 nm; 在50 ℃时, 得到网状CdS纳米线, 其长度为2-3 μm; CdS纳米棒和网状纳米线均为立方相闪锌矿结构. 荧光性质的测试表明, CdS纳米棒和网状纳米线具有优良的荧光性能, 电流-电压(I-V)特性的表征表明CdS纳米线具有很好的电导特性.     

Syntheses of CuO nanostructures in ionic liquids

A simple and efficient approach is developed to fabricate single-crystalline CuO nanostructures through an ionic liquid assisted one-step low-temperature solid-state route.Both nanoparticles(5 nm in size)and nanorods(5-10 nm in diameter and 50-100 nm in length)of monoclinic CuO were obtained. These synthesized CuO nanostructures were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),selected area electron diffraction(SAED),X-ray photoelectron spectros- copy(XPS),energy dispersive spectroscopy(EDS)and nitrogen adsorption analysis.The morpholo- gies of the nanostructures can be controlled by tuning the amount of NaOH and ionic liquids.The growth mechanism of CuO nanostructures is investigated.     

Surface tension of binary mixtures of imidazolium and ammonium based ionic liquids with alcohols, or water: cation, anion effect

The surface tensions were measured at atmospheric pressure, with use of a ring tensiometer, of a series of alcoholic solutions of closely related ionic liquids: 1-methyl-3-methylimidazolium methylsulfate, [MMIM][CH3SO4] in alcohol (methanol, or ethanol, or 1-butanol at 298.15 K), 1-butyl-3-methylimidazolium methylsulfate, [BMIM][CH3SO4] in alcohol (methanol, or ethanol, or 1-butanol at 298.15 K), 1-butyl-3-methylimidazolium octylsulfate, [BMIM][OcSO4] in alcohol (methanol, or 1-butanol at 298.15 K) and of 1-hexyloxymethyl-3-methylimidazolium tetrafluoroborate, [C6H(13)OCH2MIM][BF4], 1,3-dihexyloxymethylimidazolium tetrafluoroborate, [(C6H13OCH2)2IM][BF4] in alcohol (methanol, or 1-butanol, or 1-hexanol at 308.15 and 318.5 K) and hexyl(2-hydroxyethyl)dimethylammonium bromide, C6Br in 1-octanol at 298.15 K. The set of ammonium ionic liquids of different cations and anions (C2Br, C2BF4, C2PF6, C2N(CN)2, C3Br, C4Br and C6Br) was chosen to show the influence of small amount of the ammonium ionic liquid on the surface tension of water at 298.15 K. The influence of the cation, or anion alkyl chain length on the properties under study (densities and surface tension) was tested.     

离子液体体系中离子型锰卟啉对苯乙烯的催化氧化

以单氧给体乙酰碘苯[PhI(OAc)2]为氧源, 在无需轴向配体和有机溶剂的参与下, 离子型锰卟啉[MnⅢ(BF4)T(N-Me-4-Py)P][BF4]4和离子液体 [BMIM]BF4组成的多元离子液体体系, 在温和的反应条件下对苯乙烯的催化氧化表现出较高的活性(87%)和环氧苯乙烷选择性(90％), 并且有较好的底物普适性. 构筑的锰卟啉多元离子液体体系可以一定程度上抑制卟啉聚合和氧化降解等反应.     

Revealing long-range density fluctuations in dialkylimidazolium chloride ionic liquids by dynamic light scattering

In this study, the structures and dynamics of ionic liquids of 1-allyl-3-methylimidazolium chloride ([AMIM][Cl]) and 1-n-butyl-3-methylimidazolium chloride ([BMIM][Cl]) were studied by dynamic light scattering with polarized and depolarized geometries in the temperature range from 300 to 400 K. The temperature range covered supercooled and liquid states for [BMIM][Cl] and covered the liquid state for [AMIM][Cl]. The results show that for these ionic liquids at all chosen temperatures only one ultraslow relaxation is observed in the polarized component of dynamic light scattering, however, the ultraslow relaxation is not observed in the depolarized component. The ultraslow relaxation exhibited several typical features of the "cluster" mode generally found in glass-forming liquids and polymer melts, such as diffusive, strongly scattering-vector-dependent, and nearly exponential characters, which thus corresponded to long-range density fluctuations. The physical origin for long-range density fluctuations was the existence of heterogeneities with large characteristic length scales in these ionic liquids. It was further considered that molecules of these ionic liquids not only tended to aggregate to form dynamic clusters but also possibly formed dynamic networks in the supercooled state and the heterogeneities could exist even at temperatures higher than the melting points.     

Nucleophilicity in ionic liquids. 3. Anion effects on halide nucleophilicity in a series of 1-butyl-3-methylimidazolium ionic liquids

We have continued the study of halide nucleophilicity in ionic liquids, concentrating on the effect of changing the anion ([BF(4)](-), [PF(6)](-), [SbF(6)](-), [OTf](-), and [N(Tf)(2)](-)) when the cation is [bmim](+) (where bmim = 1-butyl-3-methylimidazolium). It was found that the nucleophilicities of all the halides were lower in all of the ionic liquids than in dichloromethane. Changing the anion affected the order of halide nucleophilicity, e.g., in [bmim][BF(4)] the order of nucleophilicity was Cl(-)>Br(-)>I(-) while in [bmim][N(Tf)(2)] the order was Cl(-)相似文献