"Zeoball" [Sn36Ge24Se132]24-: a molecular anion with zeolite-related composition and spherical shape

Ionothermal reactions of [Ge(4)Se(10)](4-) with SnCl(4)·5H(2)O yielded [BMMIm](24)[Sn(36)Ge(24)Se(132)] (ZBT-1) and [BMIm](24)[Sn(32.5)Ge(27.5)Se(132)] [ZBT-2; B(M)MIm = 1-butyl-(2,)3-(di)methylimidazolium]. These contain the largest known discrete polyanion consisting only of main-group elements. In spite of a zeolite-related composition, the 192-atom "zeoball" anion adopts a spherical shape, which has been unprecedented in the chemistry of zeolites and their homologues and relatives. Preliminary studies indicated that ZBT-1 traps I(2) molecules and induces heterolytic I-I bond cleavage.     

Supramolecular Ionic‐Liquid Gels with High Ionic Conductivity

Supramolecular ionogels were prepared by the gelation of room‐temperature ionic liquid 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([BMIm][BF₄]) with (S,S)‐bis(leucinol)oxalamide. Remarkably, the ionic conductivity of solutions and ionogels with low gelator concentrations is higher than that of neat [BMIm][BF₄]. On the basis of molecular dynamics simulations and quantum mechanical calculations, the origin of this phenomenon is attributed to the higher affinity of gelator molecules towards [BF₄]^? ions, which reduces the electrostatic attraction between [BMIm]⁺ and [BF₄]^? and thus increases their mobility. With increasing gelator concentration, the ionic conductivity decreases due to the formation of a denser gelator matrix, which hinders the pathways for ionic transport. However, even for very dense ionogels, this decrease is less than one order of magnitude relative to neat [BMIm][BF₄], and thus they can be classified as highly conductive materials with strong potential for application as functional electrolytes.     

Aerobic and Electrochemical Oxidative Cross‐Dehydrogenative‐Coupling (CDC) Reaction in an Imidazolium‐Based Ionic Liquid

The ionic liquid 1‐butyl‐3‐methylimidazolium tetrafluoroborate [BMIm][BF₄] has demonstrated high efficiency when applied as a solvent in the oxidative nitro‐Mannich carbon? carbon bond formation. The copper‐catalyzed cross‐dehydrogenative coupling (CDC) between N‐phenyltetrahydroisoquinoline and nitromethane in [BMIm][BF₄] occurred with high yield under the described reaction conditions. Both the ionic liquid and copper catalyst were recycled nine times with almost no lost of activity. The electrochemical behavior of the tertiary amine substrate and β‐nitroamine product was investigated employing [BMIm][BF₄] as electrolyte solvent. The potentiostatic electrolysis in ionic liquid afforded the desired product with a high yield. This result and the cyclic voltammetric investigation provide a better understanding of the reaction mechanism, which involves radical and iminium cation intermediates.     

Effects of additives and post‐treatment on the thermoelectric performance of vapor‐phase polymerized PEDOT films

Vapor‐phase polymerization (VPP) is an important method for the fabrication of high‐quality conducting polymers, especially poly(3,4‐ethylenedioxythiophene) (PEDOT). In this work, the effects of additives and post‐treatment solvents on the thermoelectric (TE) performance of VPP‐PEDOT films were systematically investigated. The use of 1‐butyl‐3‐menthylinidazolium tetrafluoroborate ([BMIm][BF₄], an ionic liquid) was shown to significantly enhance the electrical conductivity of VPP‐PEDOT films compared with other additives. The VPP‐PEDOT film post‐treated with mixed ethylene glycol (EG)/[BMIm][BF₄] solvent displayed the high power factor of 45.3 μW m^?1 K^?2 which is 122% higher than that prepared without any additive or post‐treatment solvent, along with enhanced electrical conductivity and Seebeck coefficient. This work highlighted the superior effect of the [BMIm][BF₄] additive and the EG/[BMIm][BF₄] solvent post‐treatment on the TE performance of the VPP‐PEDOT film. These results should help with developing the VPP method to fabricate high‐performance PEDOT films. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55 , 1738–1744     

BMIm]4[Sn9Se20]: ionothermal synthesis of a selenidostannate with a 3D open-framework structure

The reaction of [K(4)(H(2)O)(4)][SnSe(4)] with [BMIm][BF(4)] at 130-180 °C afforded [BMIm](4)[Sn(9)Se(20)] (1). The anion of the title compound represents a unique three-dimensional (3D) open framework, based on a variety of interconnectivity modes of Sn/Se units that lead to a system of six intersecting channels. 1 comprises the first example of a binary 3D open-framework selenidostannate anion and the first 3D open-framework chalcogenido metalate to be conveniently obtained by ionothermal synthesis.     

Synthesis and Structure of the Bicyclic [Sn4Se11]6– Anion in Na6Sn4Se11 · 22 H2O

Na₆Sn₄Se₁₁ · 22 H₂O can be crystallised at –8 °C as yellow‐orange needles from the 1 : 2 H₂O/CH₃OH mother liquor of a superheated reaction mixture of NaOH(s), Sn and Se. The bicyclic [Sn₄Se₁₁]^6– anion exhibits crystallographic C₂ symmetry and is composed of corner‐bridged SnSe₄ tetrahedra. Two opposite tin atoms of an Sn₄Se₄ 8‐membered ring are linked by a common Se atom, thereby affording two 6‐membered boat‐shaped Sn₃Se₃ rings with a shared Sn–Se–Sn bridging unit. [Sn₄Se₁₁]^6– thus represents the immediate precursor of the well‐known adamantane‐like [Sn₄Se₁₀]^4– anion.     

Solubility of CO2 in imidazolium-based tetrafluoroborate ionic liquids

The solubility of CO₂ in imidazolium ionic liquids (ILs), 1-butyl-3-methyl imidazolium tetrafluoroborate ([bmim][BF₄]), 1-hexyl-3-methyl imidazolium tetrafluoroborate ([hmim][BF₄]) and 1-octyl-3-methyl imidazolium tetrtafluoroborate ([omim][BF₄]) was determined at 305-25 K and pressures from 1 to 9 MPa. The influence of chain length of alkyl substituents on the imidazolium cation on the solubility of CO₂ was investigated. The differences in solubility with chain length are in the sequence [omim][BF₄] > [hmim][BF₄] > [bmim][BF₄]. The solubility data were correlated by the extended Henry's law, and enthalpy, Gibbs free energy and entropy changes were obtained.     

Synthesis and Crystal Structures of Octahedral Metal Complexes containing the New Dianion [PhP(Se,O)Se‐Se(O,Se)PPh]2−

The synthesis and structures of three new compounds are reported. [Mg₂{PhP(Se,O)Se‐Se(O,Se)PPh}₂(thf)₇(H₂O)₃] ( 1 ), [Mg{PhP(Se,O)Se‐Se(O,Se)PPh}(thf)₃(H₂O)] ( 2 ), and [Mn{PhP(Se,O)Se‐Se(O,Se)PPh}(thf)₃(H₂O)] ( 3 ) were prepared by treatment of Woollins' reagent [PhP(Se)(μ‐Se)]₂ with the corresponding hydrated metal acetates.     

Der Einfluß von Phosphoryl‐Substituenten auf die Eigenschaften P‐substituierter 2‐Methylimidazolium‐Ionen und 2‐Methylenimidazoline [1]

The Influence of Phosphoryl Substituents on the Properties of P‐Substituted 2‐Methylimidazolium Ions and 2‐Methyleneimidazolines [1] The imidazolines ImCHP(E)Ph₂ [ 6 , E = S ( a ), Se ( b )] are obtained from ImCHPPh₂ ( 4 ) and sulfur or selenium. HBF₄ reaction yields the corresponding imidazolium salts [ImCH₂P(E)Ph₂][BF₄] [ 5 , E = S ( a ), Se ( b )]. 1, 3, 4, 5‐Tetramethyl‐2‐methylenimidazoline ( 1 , ImCH₂) reacts with Ph₂P(O)Cl to give the corresponding phosphane salt [ImCH₂P(O)Ph₂]Cl ( 7 ) from which the vinyl compound ImCHP(O)Ph₂ ( 8 ) is formed through deprotonation. 8 reacts with excess HBF₄ to give the phosphine oxide BF₃ adduct [ImCH₂P(O)Ph₂ · BF₃][BF₄] ( 9 ). The crystal structures of 5a , 5b , 6b , 7 · CH₂Cl₂ and 9 · H₂O as well as preliminary data of 8 are reported and discussed on comparison with the phosphanes [ImCH₂PPh₂][BF₄] ( 3b ) and ImCHPPh₂ ( 4 ). From structural data, π‐electron delocalisation is concluded for 6b and 8 .     

Green Synthesis of Pyrano[2,3‐d]‐pyrimidine Derivatives in Ionic Liquids

Pyrano[2,3‐d]pyrimidine derivatives were synthesized in high yields by a condensation reaction between arylmethylidenemalononitrile and barbituric acid using room‐temperature ionic liquids such as 1‐n‐butyl‐3‐methylimidazolium tetrafluoroborate ([BMIm]BF₄) or 1‐butylpyridinium tetrafluoroborate ([BPy]BF₄) as solvents under neutral conditions.     

Organotin–Oxido Cluster‐Based Multiferrocenyl Complexes Obtained by Hydrolysis of Ferrocenyl‐Functionalized Organotin Chlorides

Three organotin–oxido clusters were formed by hydrolysis of ferrocenyl‐functionalized organotin chloride precursors in the presence of NaEPh (E=S, Se). [R^FcSnCl₃?HCl] ( C ; R^Fc = CMe₂CH₂C(Me)?N?N?C(Me)Fc) and [SnCl₆]^2? formed {(R^FcSnCl₂)₃[Sn(OH)₆]}[SnCl₃] ( 3 a ) and {(R^FcSnCl₂)₃[Sn(OH)₆]}[PhSeO₃] ( 3 b ), bearing an unprecedented [Sn₄O₆] unit, in a one‐pot synthesis or stepwise through [(R^FcSnCl₂)₂Se] ( 1 ) plus [(R^FcSnCl₂)SePh] ( 2 ). A one‐pot reaction starting out from FcSnCl₃ gave [(FcSn)₉(OH)₆O₈Cl₅] ( 4 ), which represents the largest Fc‐decorated Sn/O cluster reported to date.     

Ionic Liquid Ordering at an Oxide Surface

The interaction of the ionic liquid [C₄C₁Im][BF₄] with anatase TiO₂, a model photoanode material, has been studied using a combination of synchrotron radiation photoelectron spectroscopy and near‐edge X‐ray absorption fine structure spectroscopy. The system is of interest as a model for fundamental electrolyte–electrode and dye‐sensitized solar cells. The initial interaction involves degradation of the [BF₄]^? anion, resulting in incorporation of F into O vacancies in the anatase surface. At low coverages, [C₄C₁Im][BF₄] is found to order at the anatase(101) surface via electrostatic attraction, with the imidazolium ring oriented 32±4° from the anatase TiO₂ surface. As the coverage of ionic liquid increases, the influence of the oxide surface on the topmost layers is reduced and the ordering is lost.     

Reverse ATRP process of acrylonitrile in the presence of ionic liquids

An ionic liquid, 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([C₄mim] [BF₄]), was first used as the solvent in azobisisobutyronitrile (AIBN)‐initiated reverse atom transfer radical polymerization (RATRP) of acrylonitrile with FeCl₃/succinic acid (SA) as the catalyst system. The polymerization in [C₄mim][BF₄] proceeded in a well‐controlled manner as evidenced by kinetic studies. Compared with the polymerization in bulk, the polymerization in [C₄mim][BF₄] not only showed the best control of molecular weight and its distribution but also provided rather rapid reaction rate with the ratio of [C₄mim][BF₄] at 200:1:2:4. The polymerization apparent activation energies in [C₄mim][BF₄] and bulk were calculated to be 48.2 and 55.7 kJ mol^?1, respectively. Polyacrylonitrile obtained was successfully used as a macroinitiator to proceed the chain extension polymerization in [C₄mim][BF₄] via a conventional ATRP process. [C₄mim][BF₄] and the catalyst system could be easily recycled and reused after simple purification and had no effect on the living nature of polymerization. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2701–2707, 2008     

The “one-pot” synthesis of 2,5-diformylfuran,a promising synthon for organic materials in the conversion of biomass

The organic ionic oxidant 4-acetamido-2,2,6,6-tetramethyl-1-oxopiperidinium tetrafluoroborate, [Pip*(O)][BF₄], was found to be compatible with both classical organic solvents and the ionic liquids [BMIm][Cl]/[BMIm][BF₄] (BMIm is 1-butyl-3-methylimidazolium), which are essential in the conversion of cellulose biomass. A unique NMR monitoring procedure developed in our group was used to study the conversion of fructose to 2,5-diformylfuran in ionic liquids. This process can successfully be carried out in a “one-pot” fashion; [Pip*(O)][BF₄] efficiently oxidizes intermediate 5-hydroxymethylfurfural. The reaction is highly selective, giving 2,5-diformylfuran in 95% yield.     

Crystal Structures and Raman Spectra of cis‐[SnCl4(H2O)2]·2H2O,cis‐[SnCl4(H2O)2]·3H2O, [Sn2Cl6(OH)2(H2O)2]·4H2O,and [HL][SnCl5(H2O)]·2.5H2O (L=3‐acetyl‐5‐benzyl‐1‐phenyl‐4, 5‐dihydro‐1, 2, 4‐triazine‐6‐one oxime,C18H18N4O2)

The complexes cis‐[SnCl₄(H₂O)₂]·2H₂O ( 1 ), [Sn₂Cl₆(OH)₂(H₂O)₂]·4H₂O ( 3 ), and [HL][SnCl₅(H₂O)]·2.5H₂O ( 4 ) were isolated from a CH₂Cl₂ solution of equimolar amounts of SnCl₄ and the ligand L (L=3‐acetyl‐5‐benzyl‐1‐phenyl‐4, 5‐dihydro‐1, 2, 4‐triazine‐6‐one oxime, C₁₈H₁₈N₄O₂) in the presence of moisture. 1 crystallizes in the monoclinic space group Cc with a = 2402.5(1) pm, b = 672.80(4) pm, c = 1162.93(6) pm, β = 93.787(6)° and Z = 8. 4 was found to crystallize monoclinic in the space group P2₁, with lattice parameters a = 967.38(5) pm, b = 1101.03(6) pm, c = 1258.11(6) pm, β = 98.826(6)° and Z = 2. The cell data for the reinvestigated structures are: [SnCl₄(H₂O)₂]·3H₂O ( 2 ): a = 1227.0(2) pm, b = 994.8(1) pm, c = 864.0(1) pm, β = 103.86(1)°, with space group C2/c and Z = 4; 3 : a = 961.54(16) pm, b = 646.29(7) pm, c = 1248.25(20) pm, β = 92.75(1)°, space group P2₁/c and Z = 4.     

Thin-film TiO2 electrode surface characterization upon CO2 reduction processes

The effect of electrochemical reduction of CO₂ on the structure and morphology of titanium(IV) oxide thin films was examined after a fixed-potential bulk electrolysis process. Films deposited on ITO (Indium-Tin Oxide) substrates were used as the working electrodes and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF₄]) as solvent and as supporting electrolyte. Grazing incidence X-ray diffraction analysis performed before and after the electrolysis process indicated no microstructural changes of the anatase films. X-ray photoelectron spectroscopy revealed peaks associated with adsorbed carbonate ions at 288 eV and CO₂ species at 293 eV, whereas Ti2p peaks displacements for CO₂-saturated TiO₂/ITO surfaces in [BMIm][BF₄] revealed chemical bonding effects. Auger electron spectroscopy revealed a high carbon content on CO₂-exposed films, and suggested a strong chemisorption of CO₂ and CO₃²⁻ species on the TiO₂/ITO surface in [BMIm][BF₄] solvent system. A significant decrease in carbon content after bulk electrolysis indicated that the CO₂ electroreduction process is not controlled by either diffusion or by adsorption of CO₂ on the TiO₂/ITO electrode surface.     

Direct electrochemistry and electrocatalysis of myoglobin immobilized in hyaluronic acid and room temperature ionic liquids composite film

A novel biocomposite film based on hyaluronic acid (HA) and hydrophilic room temperature ionic liquid 1-ethyl-3-methyl-imidazolium tetrafluoroborate ([EMIM][BF₄]) was explored. Here, HA was used as a binder to form [EMIM][BF₄]-HA composite film and help [EMIM][BF₄] to attaching on glass carbon electrode (GCE) surface, while doping [EMIM][BF₄] in HA can effectively reduce the electron transfer resistance of HA. The composite film can be readily used as an immobilization matrix to entrap myoglobin (Mb). A pair of well-defined and quasi-reversible redox peaks of Mb was obtained at the Mb-[EMIM][BF₄]-HA composite film modified GCE (Mb-[EMIM][BF₄]-HA/GCE) through direct electron transfer between Mb and the underlying electrode. The Mb-[EMIM][BF₄]-HA/GCE showed an excellent electrocatalytic activity toward the reduction of H₂O₂. Based on the [EMIM][BF₄]-HA biocomposite film, a third-generation reagentless biosensor could be constructed for the determination of H₂O₂.     

Different Complexation Behavior of P‐Functionalized Ferrocene Derivatives Towards SnCl2, SnCl4 and SnPh2Cl2: Auto‐ionization and Redox‐Type Reactions

The novel phosphonyl‐substituted ferrocene derivatives [Fe(η⁵‐Cp)(η⁵‐C₅H₃{P(O)(O‐iPr)₂}₂‐1,2)] ( Fc^1,2 ) and [Fe{η⁵‐C₅H₄P(O)(O‐iPr)₂}₂] ( Fc^1,1′ ) react with SnCl₂, SnCl₄, and SnPh₂Cl₂, giving the corresponding complexes [(Fc^1,2)₂SnCl][SnCl₃] ( 1 ), [{(Fc^1,1′)SnCl₂}_n] ( 2 ), [(Fc^1,1′)SnCl₄] ( 3 ), [{(Fc^1,1′)SnPh₂Cl₂}_n] ( 4 ), and [(Fc^1,2)SnCl₄] ( 5 ), respectively. The compounds are characterized by elemental analyses, ¹H, ¹³C, ³¹P, ¹¹⁹Sn NMR and IR spectroscopy, ³¹P and ¹¹⁹Sn CP‐MAS NMR spectroscopy, cyclovoltammetry, electrospray ionization mass spectrometry, and single‐crystal as well as powder X‐ray diffraction analyses. The experimental work is accompanied by DFT calculations, which help to shed light on the origin for the different reaction behavior of Fc^1,1′ and Fc^1,2 towards tin(II) chloride.     

Influence of 1-alkyl-3-methylimidazolium tetrafluoroborate on the lamellar liquid crystal formed by tetraethylene glycol lauryl ether and water

Lyotropic liquid crystals (LLCs) formed in tetraethylene glycol lauryl ether–water system by the addition of 1-alkyl-3-methylimidazolium tetrafluoroborate ([C _n Mim][BF₄], n?=?2, 4, 6, 8, 10) are characterised by polarised optical microscopy and small-angle X-ray scattering techniques. A small number of [C _n Mim][BF₄] molecules can be solubilised in the liquid crystal without changing the lamellar type. These imidazolium salts are considered as an ideal kind of modifiers for the ordered structure. With different lengths of alkyl chains, [C _n Mim][BF₄] molecules appear in various domains of ordered assemblies: in the water layer for [C₂Mim][BF₄], in the water layer as well as in the polar domain for [C₄Mim][BF₄] and in the apolar domain for the other imidazolium salts with long alkyl chains. Diverse distributions of [C _n Mim][BF₄] molecules in the inner structure bring about their specific influence on the lamellar phase. These results enlighten the use of diverse alkyl-substituted imidazolium salts in modulating LLC and other assemblies and also enrich the aggregation behaviour of these assemblies.     

Effects of organic solvents and ionic liquids on the aminolysis of (RS)-methyl mandelate catalyzed by lipases

The enzymatic resolution of (RS)-methyl mandelate with n-butylamine using lipases in organic solvents (n-hexane, tert-butanol, and chloroform) and ionic liquids [BMIm][BF₄] and [BMIm][PF₆] is reported. The amide configuration is dependent on the organic solvent. When using mixtures of chloroform or tert-butanol/ionic liquids (10:1 v/v) with CAL-B as the catalyst, the amides were obtained in high enantiomeric excess (ee_p >99% and E >200).