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This work demonstrates the feasibility of aliphatic dicarbamate PCMs as inexpensive, stable and sustainable materials for the storage of renewable energy in the “Thermal Battery”.

Proton transfer is a key step of the lithium-mediated electrochemical reduction of nitrogen to ammonia. Herein, we investigate the impact of the chemical nature of the proton carrier on the performance and highlight shuttles that enable effective ammonia synthesis. more...

Thermal energy storage systems utilising phase change materials have the potential to overcome the intermittency issues associated with most renewable energy sources, significantly contributing to the decarbonisation of the energy sector. While the concept of storing energy in the latent heat of a phase transition is not new, large scale systems employing this concept have not yet realised their full potential. This is in large part due to the shortcomings of conventionally used materials – whether it be issues with their flammability, chemical and thermal instability, corrosivity, poor cycling stability, or a combination of these. Ionic liquids offer a suite of inherent “green” properties that translate well into the field of phase change materials, namely low volatility, low flammability, and good thermal and chemical stability, alongside the potential to tune their chemical and phase properties. In this Perspective, we discuss the evolution and promise of the emerging field of ionic liquids for renewable thermal energy storage. Systems are considered from a holistic, sustainable point of view, demonstrating the importance of assessing material origins and synthetic pathways as well as system performance through lifecycle assessment. We elucidate the emerging design rules for optimising thermal properties, and in doing so attempt to provide an overview of promising emerging systems and future directions. more...

Thermal energy storage technologies utilizing phase change materials (PCMs) that melt in the intermediate temperature range, between 100 and 220 °C, have the potential to mitigate the intermittency issues of wind and solar energy. This technology can take thermal or electrical energy from renewable sources and store it in the form of heat. This is of particular utility when the end use of the energy is also as heat. For this purpose, the material should have a phase change between 100 and 220 °C with a high latent heat of fusion. Although a range of PCMs are known for this temperature range, many of these materials are not practically viable for stability and safety reasons, a perspective not often clear in the primary literature. This review examines the recent development of thermal energy storage materials for application with renewables, the different material classes, their physicochemical properties, and the chemical structural origins of their advantageous thermal properties. Perspectives on further research directions needed to reach the goal of large scale, highly efficient, inexpensive, and reliable intermediate temperature thermal energy storage technologies are also presented. more...

Shuttling protons in ammonia synthesis An electrochemical route to ammonia could substantially lower the greenhouse gas emissions associated with the current thermal Haber-Bosch process. One relatively promising option under study involves reductive formation of lithium nitride, which can be protonated to ammonia. However, the ethanol used to date as a local proton source in these studies may degrade under the reaction conditions. Suryanto et al. report the use of a tetraalkyl phosphonium salt in place of ethanol (see the Perspective by Westhead et al. ). This cation can stably undergo deprotonation–reprotonation cycles and, as an added benefit, it enhances the ionic conductivity of the medium. Science , abg2371, this issue p. 1187 ; see also abi8329, p. 1149 more...

The development of new phase change materials that can store large amounts of renewable thermal energy will aid the decarbonisation of the energy sector that is crucial for future generations. For substantial development of these materials, understanding the relationships that underpin the enthalpy of fusion (ΔHf) is critical. In the present work, the role of hydrogen bonding in the energy storage mechanism is elucidated by single-crystal X-ray diffraction and Hirshfeld surface analyses on a range of novel and known protic organic salts based on the guanidinium, acetamidinium, and formamidinium cations. Bonding motifs and strengths are probed through the steric and electronic properties of the anions, specifically with the use of the methanesulfonate ([CH3SO3]−), trifluoromethanesulfonate ([CF3SO3]−), para-toluenesulfonate ([C7H7SO3]−), trifluoroacetate ([CF3COO]−) and chloride (Cl−) anions. We consider entropic contributions to melting thermodynamics, and the results highlight the importance of strong hydrogen bonds in the solid state, finding an increased density of hydrogen bonds can be detrimental to ΔHf if the result is non-geometrically favoured or bifurcated interactions. The results propose a new rationale for the design of these systems through matching the number of hydrogen bond donor and acceptor sites. As well as increasing the linearity and strength of hydrogen bonds, such matching aids in the formation of predictable, energetically favourable supramolecular motifs, that contribute to ΔHfvia the energetic cost of their dislocation upon melting. These insights should inform the design of future high-performance phase change materials that can efficiently store sustainable energy, helping to overcome the intermittency issues typically associated with renewable energy systems. more...

Charge transport properties in single-walled carbon nanotubes (SWCNTs) can be significantly modified through doping, tuning their electrical and thermoelectric properties. In our study, we used more than 40 nitrogen-bearing compounds as dopants and determined their impact on the material's electrical conductivity. The application of nitrogen compounds of diverse structures and electronic configurations enabled us to determine how the dopant nature affects the SWCNTs. The results reveal that the impact of these dopants can often be anticipated by considering their Hammett's constants and pKa values. Furthermore, the empirical observations supported by first-principles calculations indicate that the doping level can be tuned not only by changing the type and the concentration of dopants but also by varying the orientation of nitrogen compounds around SWCNTs. more...

In addition to its use in the fertilizer and chemical industries

As a result of strict regulations of phthalate plasticizers, alternative non-phthalate forms are desired and increasingly used. This work presents a synthetic method for alternative plasticizers (dialkyl succinates and adipates) via esterification of succinic and adipic acid with alcohols: butan-1-ol and 2-ethylhexan-1-ol. Ionic liquids were synthesized by the reaction of triethylamine with over-equimolar (1:2.7) amounts of sulfuric(VI) acid, which were used as an acidic catalyst and solvent. The two-phase liquid–liquid system was formed during the reaction due to immiscibility of the esters with the ionic liquid. This phenomenon is a driving force of this process, shifting the equilibrium toward the product formation. As a result, dialkyl succinates and adipates were obtained in high yields (99%) and selectivities (&gt, 99%), under mild reaction conditions at 70–80 °C and using a 4:1 molar ratio of alcohol to acid and 15 mol% of catalyst. The catalyst was recycled 10 times without any loss of activity. This alternative method is highly competitive: it involves a simple procedure for product isolation as well as a high yield and purity of the resulting esters. These advantages make this method sustainable and promising for industrial applications. more...

Carbohydrate moieties were combined with various cross-linkable anions (thiocyanate [SCN], tetracyanoborate [TCB], tricyanomethanide [TCM], and dicyanamide [DCA]) and investigated as precursors for the synthesis of nitrogen-doped and nitrogen-/sulfur-co-doped carbons. The influence of the molecular structures of the precursors on their thermophysical properties and the properties of the derived carbon materials was elucidated and compared to petroleum-derived analogs. A carbohydrate-based ionic liquid featuring an [SCN] anion yielded more carbon residues upon carbonization than its 1-ethyl-3-methylimidazolium analog, and the resulting dual-doping of the derived carbon material translated to enhanced catalytic activity in the oxygen reduction reaction. more...

A dearth of inexpensive means of energy storage is constraining the expansion of intermittent renewable energy sources such as sun and wind. Thermal energy storage technology utilizing phase-change materials (PCMs) is a promising solution, enabling storage of large quantities of thermal energy at a relatively low cost. Guanidinium mesylate, which melts at 208 °C with latent heat of fusion of ΔHf =190 J g-1 is a promising PCM candidate for these applications.[1] Here, studies on guanidinium organic salts were conducted, including heat capacity, thermal conductivity, advanced thermal stability, long-term cycling, and economic analysis. The data place guanidinium mesylate among the best PCMs operating in the 100-220 °C temperature region in terms of thermal energy storage, with total volumetric energy storage measured as 622 MJ m-3 (173 kWh m-3 ). Additionally, it was shown to be stable during cycling, with over 400 cycles performed. Simple economic analysis indicated a cost of 6 USD per MJ of stored thermal energy. This study proves that guanidinium mesylate and potentially other similar salts can be feasible as PCMs for inexpensive energy storage for renewable energy storage applications. more...

Apart from its role as a main precursor of the synthetic fertiliser production, ammonia is likely to become an even more important chemical in the future due to its prospects as an energy carrier.(1) To meet the associated growing demand while meeting the CO2 emission reductions targets, recent efforts have aimed to translate the conventional polluting NH3 synthesis to low CO2 emissions technology by supplying the Haber-Bosch reactors with H2 derived from renewable-powered water electrolysis rather than steam methane reforming.(2) This solution will likely to be implemented in many NH3 synthesis plants soon, but the most preferred future technology for green ammonia synthesis is through a 100% renewable-powered, one step electrochemical process involving nitrogen reduction at the cathode and water oxidation at the anode. However, the possibility of direct dinitrogen reduction with traditional heterogeneous catalysts in both aqueous and aprotic electrolyte solutions at practical rates and faradaic efficiencies is yet to be proven,(3, 4) which calls for investigations of alternative pathways. One prominent possibility, with clear practical prospects, is the indirect lithium redox mediated process in organic electrolytes, which has been evidenced as genuine and by far the most efficient process to electrochemically convert N2 to NH3.(5) However, several key challenges, including insufficiently high yield rate and faradaic efficiency as well as instability of the system, are yet to be resolved before the lithium-mediated nitrogen reduction reaction (Li-NRR) can be considered a process of applied significance. Our first step towards this aim was to introduce a stable phosphonium cation/ylide proton shuttle that delivers protons to the cathode to support rapid and controllable conversion of lithium nitride into ammonia.(6) It was demonstrated that phosphonium cation provides favourable proton activity in the system, which enables high Li-NRR faradaic efficiency of 69 ± 1 %. Moreover, the phosphonium shuttle exhibits high stability under the reaction conditions, i.e. was genuinely able to cycle between anode and cathode without being consumed. Our further efforts have focussed on understanding the effects of the electrolyte-electrode environment on the Li-NRR kinetics. As a result of this investigation, a system configuration that enables the electroreduction of N2 to ammonia at a faradaic efficiency closely approaching 100% was discovered. Moreover, the synthesis can run in both uninterrupted and interrupted regimes on a timescale of days. The rate of ammonia electrosynthesis in the Li-NRR with the optimised electrode-electrolyte interface can achieve as high as ca 500 nmol s-1 cm-2 (per geometric electrode surface area) with electrodes of cm2 scale. Finally, we examined the degradation of the electrolyte solution components during the high-performance Li-NRR. It was found that the major source of these undesired processes are the anode processes rather than the cathode. This highlights the urgent need for the development of effective H2- or H2O-feed anodes that can be integrated with the lithium mediated process. This and other future challenges on our way towards achieving sustainable and stabile NH3 electrosynthesis system to support the development of the Ammonia Economy will be highlighted. D. R. MacFarlane, J. Choi, B. H. R. Suryanto, R. Jalili, M. Chatti, L. M. Azofra and A. N. Simonov, Adv. Mater., 32, 1904804 (2020). D. R. MacFarlane, P. V. Cherepanov, J. Choi, B. H. R. Suryanto, R. Y. Hodgetts, J. M. Bakker, F. M. Ferrero Vallana and A. N. Simonov, Joule, 4, 1186 (2020). H.-L. Du, T. R. Gengenbach, R. Hodgetts, D. R. MacFarlane and A. N. Simonov, ACS Sustainable Chem. Eng., 7, 6839 (2019). H.-L. Du, R. Y. Hodgetts, M. Chatti, C. K. Nguyen, D. R. Macfarlane and A. N. Simonov, J. Electrochem. Soc., 167, 146507 (2020). B. H. R. Suryanto, H.-L. Du, D. Wang, J. Chen, A. N. Simonov and D. R. MacFarlane, Nat. Catal., 2, 290 (2019). B. H. Suryanto, K. Matuszek, J. Choi, R. Y. Hodgetts, H.-L. Du, J. M. Bakker, C. S. Kang, P. V. Cherepanov, A. N. Simonov and D. R. MacFarlane, Science, 372, 1187 (2021). more...

Alkyl levulinates are bio-derived chemicals, increasingly popular for their uses as solvents, additives and intermediates. However, efficient and recyclable catalysts for their synthesis are still the subject of intensive research. In this study, a wide range of alkyl levulinates was synthesized under mild conditions (room temperature, atmospheric pressure), using inexpensive and efficient Bronsted acidic ionic liquids (ILs) based on sulfuric acid and off-the-shelf bases. Acidity of the ILs was closely related to their activity. The ILs could be easy separated and recycled, without significant changes in conversion or selectivity over 10 cycles (yields ca. 90–95%). Under optimized conditions, a 99% yield of pentyl levulinate (model reaction) was achieved. The method was demonstrated to be efficient in the synthesis of levulinates of C1-C16 linear, branched and cyclic alcohols. This innovative, green route to alkyl levulinates fits well within the sustainable development strategy. more...

The sodium-ion battery (SIB) is proposed as a complementary technology to today's commercially dominant lithium-ion battery (LIB). While much know-how can be transferred from LIBs to SIBs, adjustments are still necessary, not the least for the electrolytes employed. Here the use of anion amphiprotic ionic liquid (AAIL) based electrolytes is proposed for SIB application. Two different AAILs, based on organic trifluoromethylsulfonylamide (TFSAm) and inorganic HSO4− anions, respectively, doped with NaTFSI salt have been studied, focusing on electrochemical stability and transport properties, complemented by studies of the ion–ion interactions, and final sodium-ion battery performance via stripping/plating vs. sodium metal electrodes. more...

Inexpensive Br&oslash, nsted acidic ionic liquids based on trimethylamine and sulfuric acid are proposed as both solvents and catalysts in the synthesis of alternative plasticizer bis(2-ethylhexyl) terephthalate, which has a broad spectrum of applications in plasticization processes. The utilization of 50 mol % of Br&oslash, nsted ionic liquid led to the full conversion of terephthalic acid after 8 h of reaction at 120 &deg, C. Additionally, a 100% selectivity of bis(2-ethylhexyl) terephthalate was obtained. The advantage of the presented reaction system is based on the formation of a biphasic system during the reaction. The bottom phase consists of an ionic liquid and water, and the upper phase is created by the ester and unreacted alcohol. This phenomenon helps overcome the equilibrium of the reaction and drives it towards a high yield of product. The presented new approach is proposed as a safe, cost-effective, and alternative method to conventional processes with organometallic compounds that, in turn, leads to greener and a more economically viable technology. more...

The kinetics of polymerization of Bisphenol-A diglycidyl ether (DGEBA), a well-known epoxy resin, with two ionic amines 1-(3-aminopropyl)-3-butylimidazolium bis(trifluoromethylsulfonyl)imide ([apbim][NTf2]) and the tetrabutylammonium leucine ([N4444][Leu]) have been studied with the use of differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS) at various temperatures. We found many fundamental differences between the progress of this reaction with respect to the classical system (curing of epoxy resin with ordinary nonconducting hardeners). One of the most significant differences is related to the mechanism of polymerization. It is worthwhile to mention that usually the autocatalytic model is used to describe the curing of DGEBA with ordinary amines. However, herein, the kinetic curves followed a clearly exponential shape characteristic of first-order kinetics. We claim that the change in mechanism of polymerization is related to the presence of a conducting amine that acts as... more...

Thermal energy storage technology utilizing phase-change materials (PCMs) can be a promising solution for the intermittency of renewable energy sources. This work describes a novel family of PCMs based on the pyrazolium cation, that operate in the 100-200 °C temperature range, offering safe, inexpensive capacity and low supercooling. Thermal stability and extensive cycling tests of the most promising PCM candidate, pyrazolium mesylate (Tm =168±1 °C, ΔHf =160 J g-1 ±5 %, ΔHtotalv =495 MJ m-3 ±5 %) show potential for its use in thermal storage applications. Additionally, this work discusses the molecular origins of the high thermal energy storage capacity of these ionic materials based on their crystal structures, revealing the importance of hydrogen bonds in PCM performance. more...

Renewable energy has the ultimate capacity to resolve the environmental and scarcity challenges of the world’s energy supplies. However, both the utility of these sources and the economics of their implementation are strongly limited by their intermittent nature; inexpensive means of energy storage therefore needs to be part of the design. Distributed thermal energy storage is surprisingly underdeveloped in this context, in part due to the lack of advanced storage materials. Here, we describe a novel family of thermal energy storage materials based on pyrazolium cation, that operate in the 100-220°C temperature range, offering safe, inexpensive capacity, opening new pathways for high efficiency collection and storage of both solar-thermal energy, as well as excess wind power. We probe the molecular origins of the high thermal energy storage capacity of these ionic materials and demonstrate extended cycling that provides a basis for further scale up and development. more...

Projekt sfinansowany ze środkow Narodowego Centrum Nauki (projekt badawczy UMO-2014/13/N/ST8/00127).

Baeyer–Villiger oxidation of cyclic ketones, using H2O2 as the oxidising agent, was systematically studied using a range of metal chlorides in different solvents, and in neat chlorogallate(III) ionic liquids. The extremely high activity of GaCl3 in promoting oxidation with H2O2, irrespective of solvent, was reported for the first time. The activity of all other metal chlorides was strongly solvent-dependent. In particular, AlCl3 was very active in a protic solvent (ethanol), and tin chlorides, SnCl4 and SnCl2, were active in aprotic solvents (toluene and dioxane). In order to eliminate the need for volatile organic solvent, a Lewis acidic chlorogallate(III) ionic liquid was used in the place of GaCl3, which afforded typically 89–94% yields of lactones in 1–120 min, at ambient conditions. Raman and 71Ga NMR spectroscopic studies suggest that the active species, in both GaCl3 and chlorogallate(III) ionic liquid systems, are chlorohydroxygallate(III) anions, [GaCl3OH]−, which are the products of partial hydrolysis of GaCl3 and chlorogallate(III) anions; therefore, the presence of water is crucial. more...

A range of Lewis acidic metal chlorides were tested as homogeneous catalysts in a model Diels–Alder reaction; AlCl3 and GaCl3 performed best in terms of conversion and endo : exo selectivity. Based on this outcome, the corresponding chlorometallate(III) ionic liquids were tested as homogeneous catalysts, without a decrease in performance compared to the chlorides. Finally, these ionic liquids were heterogenised by covalent tethering of the cation onto a multimodal porous silica support; such supported chlorogallate(III) ionic liquids are reported for the first time. Supported chlorometallate(III) ionic liquids were used as recyclable heterogeneous catalysts for the Diels–Alder reaction under solventless conditions. High yields (99%) and high endo-selectivities (95%) were obtained after very short reaction times (5 min) at near-ambient temperature (25 °C). more...

In this paper, the kinetics of the radical polymerization of two monomeric ionic liquids: 1-ethyl- and 1-butyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide ([evim][NTf2] and [bvim][NTf2], respectively) as well as the molecular dynamics of the obtained polymers were investigated by means of Broadband Dielectric Spectroscopy (BDS), Fourier Transform Infra-Red (FTIR) spectroscopy and Differential Scanning Calorimetry (DSC). We propose a novel method of dielectric data analysis, to extract information on the progress of polymerization in highly conductive materials. It was found that the progress of reaction can be easily monitored by measuring the time evolution of dc conductivity, which correlates very well with the monomer conversion estimated from calorimetric or FTIR investigations. Additionally, it is clearly shown that even a small modification in the chemical structure, i.e. the length of the alkyl substituent, of monomeric ionic liquids leads to a dramatic change in the properties of the produced polymers. The obtained results are discussed in light of recent studies indicating a completely different tendency to nanostructure ordering in the investigated monomeric ionic liquids. more...

Friedel–Crafts alkylation of benzene with 1-decene was catalysed by a new family of liquid Lewis acids: liquid coordination complexes (LCCs). LCCs are prepared by mixing a metal halide (e.g. GaCl3) and a donor molecule (e.g. N,N-dimethylacetamide, urea, or trioctylphosphine oxide), with the metal halide typically used in excess. This leads to the formation of a eutectic mixture comprised of charged and neutral species in a dynamic equilibrium. GaCl3-based LCCs were used in catalytic amounts, giving high reaction rates under ambient conditions, with selectivities to 2-phenyldecane superior to those previously reported in the literature. The influence of reaction conditions and catalyst composition on the reaction rate and selectivity was investigated. Optimised reaction conditions were suggested. This exploratory study offers promise with regard to the development of safer, LCC-based alternatives to HF in industrial alkylations. more...

The application of the peroxy ionic liquid, 1-butyl-3-methylimidazolium peroxymonosulphate, as an oxidation agent and a solvent for the synthesis of epoxides was described. The 2.5-molar excess of the peroxy ionic liquid to olefin was applied. The reaction system consisted of 1,1,1-trifluoroacetone as an oxirane precursor, which was used with the molar ratio of 1 : 3 relative to olefin and water solution of NaHCO3. Under these conditions the epoxidation of 4-bromocinnamic acid led to the epoxide formation at the ambient temperature in 30 minutes. Dioxiranes, generated from the peroxy ionic liquid and 1,1,1-trifluoroacetone, demonstrated encouraging potential for the epoxidation of a variety of other olefins: styrene, limonene, stilbene, linalyl acetate and a complex steroid molecule with high yields of final epoxides from 65–98%. more...

The electrochemical deposition of zinc coatings from 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) baths on steel substrate was described in this paper. The influence of [ZnCl2]/[BMIMCl] ratio, current density as well as temperature have been investigated. It was found that electrodeposition in all of tested baths and parameters allowed to obtain zinc coatings. The surface of coatings were matte and in the most of cases the coating morphology was not homogenous. On the basis of corrosion investigation it was pointed out that application of the baths of higher ZnCl2content are more beneficial for zinc coatings electrodeposition that the one of [ZnCl2]/[BMIMCl]= 2:3. more...

Aiming at inexpensive Bronsted-acidic ionic liquids, suitable for industrial-scale catalysis, a family of protonic ionic liquids based on nitrogen bases and sulfuric acid has been developed. Variation of the molar ratio of sulfuric acid, χH2SO4, was used to tune acidity. The liquid structure was studied using 1H NMR and IR spectroscopies, revealing the existence of hydrogen-bonded clusters, [(HSO4)(H2SO4)]−, for χH2SO4 > 0.50. Acidity, quantified by Gutmann Acceptor Number (AN), was found to be closely related to the liquid structure. The ionic liquids were employed as acid catalysts in a model reaction; Fischer esterification of acetic acid with 1-butanol. The reaction rate depended on two factors; for χH2SO4 > 0.50, the key parameter was acidity (expressed as AN value), while for χH2SO4 > 0.50 it was the mass transport (solubility of starting materials in the ionic liquid phase). Building on this insight, the ionic liquid catalyst and reaction conditions have been chosen. Conversion values of over 95% were achieved under exceptionally mild conditions, and using an inexpensive ionic liquid, which could be recycled up to eight times without diminution in conversion or selectivity. It has been demonstrated how structural studies can underpin rational design and development of an ionic liquid catalyst, and in turn lead to a both greener and economically viable process. more...

A new method for the rapid synthesis of lactones via the one-pot oxidation of alcohols with potassium peroxymonosulphate in an ionic liquid was developed. The use of microwave or ultrasonic irradiation increased the reaction rates significantly. Additionally, new peroxymonosulphate ionic liquids were synthesised and used as effective oxidants in the synthesis of lactones. more...

The synthesis and characterisation of new hydrogen-bond-rich ionic liquids and studies of their catalytic performance in Diels–Alder reactions are described. D-Glucose and chloroalcohols were used as the raw materials and as the sources of hydroxyl groups for the synthesis of ionic-liquid cations, whereas weakly coordinating bis(trifluoromethylsulfonyl)imide was used as the anion. The new ionic liquids were analysed by 1H and 13C NMR spectroscopy and by ESI-MS experiments, which confirmed their structures. In addition, the thermal data of the studied ionic liquids measured by differential scanning calorimetry and thermogravimetric analysis showed that these compounds tend to form a glass at temperatures in the range of −29 °C to −16 °C and are thermally stable from ambient temperature to at least 430 °C, most likely because of the presence of bis(trifluoromethylsulfonyl)imide anions. The performance of the ionic liquids in the model reaction of cyclopentadiene with diethyl maleate or methyl acrylate was investigated. The studied ionic liquids showed high activity even when present in catalytic amounts (4 mol% with respect to the dienophile). An increase in the number of hydroxyl groups present in the ionic liquid structure resulted in higher reaction rates. more...

Ionic liquids based on the tricoordinate borenium cation were used for the first time as Lewis acid catalysts for a model Diels–Alder reaction. The conversion of the dienophile was successfully correlated with the Gutmann acceptor number values of the ionic liquids. Borenium ionic liquids exceeded the performance of catalysts reported in the literature. more...

Broadband dielectric spectroscopy (BDS) and differential scanning calorimetry (DSC) have been employed to probe dynamics and charge transport of 1-butyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide ([bvim][NTf2]) confined in native uniaxial AAO pores as well as to study kinetics of radical polymerization of the examined compound as a function of the degree of confinement. Subsequently, the electronic conductivity of the produced polymers was investigated. As observed, polymerization carried out at T = 363 K proceeds faster under confinement with some saturation effect observed for the sample in pores of smaller diameter. Obtained results were discussed in the context of the very recent reports showing that the free volume of the confined material is higher with respect to the bulk one. It was also noted that conductivity of poly[bvim][NTf2] is significantly higher with respect to the macromolecules obtained upon bulk polymerization. Moreover, charge transport of the confined macromolecules is eve... more...

Inexpensive Brønsted acidic ionic liquids, suitable for industrial-scale catalysis, are reported as reaction media and catalysts for the Beckmann rearrangement of cyclohexanone oxime to ϵ-caprolactam. A family of protic ionic liquids was synthesised from nitrogen bases (1-methylimidazole, N,N,N-triethylamine, N-methylpyrrolidine, 2-picoline) and sulfuric acid by proton transfer in a simple, inexpensive, solvent-free, one-step process. The density, viscosity, conductivity, and ionicity of the synthesised ionic liquids were determined. Variation in the molar ratio of sulfuric acid (χH2SO4=0.67 and 0.75) was used to tune the acidity of these protic ionic liquids, which showed extremely high catalytic activity in the Beckmann rearrangement of cyclohexanone oxime to ϵ-caprolactam. Both the structure of the cation and the sulfuric acid molar ratio strongly affect the rearrangement of cyclohexanone oxime. The most active ionic liquid, based on the 1-metyhylimidazolium cation, χH2SO4=0.75, afforded high conversion of oxime combined with very good selectivity under mild conditions (110°C, 15min). The product could be extracted from the reaction mixture, eliminating the need for the neutralisation step that exists in conventional processes. The combination of affordable catalyst and process advantages leads to a greener alternative, competitive against existent industrial applications. more...

The synthesis and characterisation of new hydrogen-bond-rich ionic liquids and studies of their catalytic performance in Diels–Alder reactions are described. D-Glucose and chloroalcohols were used as the raw materials and as the sources of hydroxyl groups for the synthesis of ionic-liquid cations, whereas weakly coordinating bis(trifluoromethylsulfonyl)imide was used as the anion. The new ionic liquids were analysed by 1H and 13C NMR spectroscopy and by ESI-MS experiments, which confirmed their structures. In addition, the thermal data of the studied ionic liquids measured by differential scanning calorimetry and thermogravimetric analysis showed that these compounds tend to form a glass at temperatures in the range of −29 °C to −16 °C and are thermally stable from ambient temperature to at least 430 °C, most likely because of the presence of bis(trifluoromethylsulfonyl)imide anions. The performance of the ionic liquids in the model reaction of cyclopentadiene with diethyl maleate or methyl acrylate was investigated. The studied ionic liquids showed high activity even when present in catalytic amounts (4 mol% with respect to the dienophile). An increase in the number of hydroxyl groups present in the ionic liquid structure resulted in higher reaction rates. more...