Imidazolium Thiocyanate Research Articles

Stable and Efficient Dye-Sensitized Solar Cells and Supercapacitors Developed Using Ionic-Liquid-Doped Biopolymer Electrolytes.

An ionic liquid (IL) 1-ethyl, 2-methyl imidazolium thiocyanate incorporated biopolymer system is reported in this communication for applications in dual energy devices, i.e., electric double-layer capacitors (EDLCs) and dye-sensitized solar cells (DSSCs). The solution caste method has been used to synthesize ionic-liquid-incorporated biopolymer electrolyte films. The IL mixed biopolymer electrolytes achieve high ionic conductivity up to the order of 10-3 S/cm with good thermal stability above 250 °C. Electrical, structural, and optical studies of these IL-doped biopolymer electrolyte films are presented in detail. The performance of EDLCs was evaluated using low-frequency electrochemical impedance spectroscopy, cyclic voltammetry, and constant current charge-discharge, while that of DSSCs was assessed using J-V characteristics. The EDLC cells exhibited a high specific capacitance of 200 F/gram, while DSSCs delivered 1.53% efficiency under sun conditions.

Highly conducting corn starch doped ionic liquid solid polymer electrolyte for energy storage devices

In this study, a new biopolymer electrolyte (BPE) is successfully developed using corn starch complexed with ammonium iodide (NH4I) as host, and low viscosity ionic liquid 1-Ethyl, 3-Methyl Imidazolium Thiocyanate (EMImSCN), as a plasticizer. This ionic liquid doped BPE shows high ionic conductivity of the order 10−4 S/cm and electrochemical stability window more than 3 V, which is suitable for electrochemical application. The ionic transference number (tion) of 0.98 confirms the system to be predominantly ionic in nature. Fourier transform infrared spectroscopy (FTIR) shows complex nature, while polarized optical microscopy (POM) gives us an idea about the semi-crystalline nature of BPE. Maximum conducting ionic liquid doped BPE sandwiched electric double layer capacitor (EDLC) and dye sensitize solar cell (DSSC) shows efficient performance.

Two-step synthesized sulfonic acid functionalized imidazolium thiocyanate solid acid catalyst for thiocyanation of various electron rich arenes by metal-free method in water

An eco-friendly, highly efficient, and novel sulfonic acid functionalized imidazolium thiocyanate (Imidazole-SO3H)/SCN and sulfonic acid functionalized imidazolium chloride (Imidazole-SO3H)/Cl solid acid catalyst were successfully synthesized. The structure of catalyst was characterized by various analyses such as FT-IR, 1H NMR and 13C NMR spectroscopy. The thiocyanation reaction of various electron rich arenes such as anilines, indoles, phenols, and other aromatic compounds were selected to show the catalytic performance and efficiency of the as-prepared solid acid catalyst, and excellent yields of the corresponding aryl and heteroaryl thiocyanates derivatives were obtained under metal-free and green conditions in water. In addition, one of the important features of current method is when the thiocyanation reaction is carried out with (Imidazole-SO3H)/SCN, this reagent has a dual role in the reaction, both as thiocyanation agent and as acidic group. On the other hand, (Imidazole-SO3H)/Cl as a catalyst plays just as acidic group in reaction. The current procedure offers advantages such as metal-free and green conditions, simple procedure, the use of a commercially available reagent, simple reaction work-up, ease of separation using simple filtration, and suitable performance in the reusability of the catalyst.

Separation of propylene and propane by functional mixture of imidazolium thiocyanate ionic liquid‐organic solvent‐cuprous salt

AbstractThis work presented the preparation of two new systems comprised of ionic liquids (ILs), organic solvent, and cuprous salt. Consequently, their absorption ability was investigated for propylene (C3H6) and propane (C3H8) and their mixtures at 100 kPa‐700 kPa pressure and 298 K‐318 K temperature. Representative ILs were 1‐butyl‐3‐methylimidazolium thiocyanate ([C4mim]SCN) and 1‐ethyl‐3‐methylimidazolium thiocyanate ([C2mim]SCN). N,N‐dimethylformamide (DMF) and cuprous thiocyanate (CuSCN) were selected for the absorption system. The effects of operating parameters like Cu+ concentration, pressure, temperature, and recycling of ILs absorbency were examined and compared with the literature. It was observed that C3H6 shows a chemical absorption while C3H8 undergoes a physical one by [C4mim]SCN‐DMF‐CuSCN and [C2mim]SCN‐DMF‐CuSCN, and an increase in concentration of Cu + effectively improves the absorption capability for C3H6 and the selectivity of C3H6/C3H8. Furthermore, [C4mim]SCN‐DMF‐CuSCN had higher absorption capability and selectivity for C3H6 than [C2mim]SCN‐DMF‐CuSCN. [C4mim]SCN‐CuSCN‐2.0 M absorbed 0.637 mol of C3H6 per litre while 0.16 mol of C3H8 per litre at 700 kPa and 298 K, with a selectivity of 3.9. This work shows that new combination of organic solvent and ILs with Cu+ salt is a new class of potential reactive absorbents to separate C3H6 and C3H8.

Electrophilic Cyanative Alkenylation of Arenes.

A variety of appropriately substituted internal alkynes were transformed into the corresponding cyano-substituted phenanthrenes, dihydronaphthalenes, and cyclohepta-1,3,5-trienes in moderate to excellent yields by treatment with imidazolium thiocyanate 1, which serves as an easy to handle [CN]+ precursor, in the presence of BCl3. The synthetic value of the method is additionally demonstrated by the transformation of the primarily obtained products into heavily substituted quinolines. Additionally, the dynamic properties of the prepared dibenzocyclohepta-1,3,5-trienes have been investigated.

High thermally stable hybrid materials based on amorphous porous silicon nanoparticles and imidazolium-based ionic liquids: Structural and chemical analysis

Compared to conventional solvents, ionic liquids (ILs) are highly recognized for their ability to enhance the dispersion of nanoparticles (NPs). However, the thermal stability of the ILs-based nanocomposites is a vital parameter for their processing applications. Here, we scrutinized the thermal stability of a series of different imidazolium ion-based ILs before and after incorporating amorphous porous silicon (ap-Si) NPs. The results show that regardless of the obtained quality dispersion, the thermal stability of the host ILs was never regressed. The combination of ap-Si NPs and bmim-SCN (1-buthyl-3-methyl imidazolium thiocyanate) induced highly dispersed framework with an enhanced thermal stability (∼15 °C shift to higher temperature). Likewise, the emim-BF 4 (1-ethyl-3-methylimidazolium tetrafluoroborate) coated the ap-Si NPs forming a very stable dispersion along with a good thermal stability (∼8 °C shift). On the other hand, the thermal stability of bmim-Ac (1-buthyl-3-methylimidazolium acetate) was not affected owing to the high viscosity of bmim-Ac that limited the dispersion of ap-Si NPs at room temperature. Throughout our study, we explored the intermolecular interactions using SEM, TEM, Raman spectroscopy and XRD. We probed the thermal stability of the fabricated dispersions using TGA, and DSC as part of characterization methodology.

Separation of cresol from coal tar by imidazolium-based ionic liquid [Emim][SCN]: Interaction exploration and extraction experiment

Cresol is a valuable chemical raw material which is mainly separated from coal tar. In this work, imidazolium-based ionic liquid (IL) 1-ethyl-3-methyl imidazolium thiocyanate ([Emim][SCN]) was synthesized and used to separate cresol from coal tar. The extraction effect of IL on p-cresol was investigated, and the key experimental factors such as mass ratio of extraction agent to model oil, extraction temperature, and extraction time were studied and optimized. Under optimal conditions, the extract efficiency can reach up to 98.25%. Furthermore, quantum chemical calculation was used to explore the interaction of cresol with IL at the molecular level. And the calculation results were verified by infrared spectrum analysis. The results show that H-bond between the cresol and IL [Emim][SCN] are the main driving force of this separation process, and the interaction with p-cresol is the strongest.

Microwave Synthesis of Fused Pyrans by Humic Acid Supported Ionic Liquid Catalyst and Their Antimicrobial, Antioxidant, Toxicity Assessment, and Molecular Docking Studies

A series of fused quinolinyl and quinolonyl pyrans were synthesized via a one‐pot reaction of quinolinyl and quinolonyl carbaldehydes, malononitrile, and a 1,3‐diketone. The reactions were catalyzed by a new humic acid supported 1‐butyl‐3‐methyl imidazolium thiocyanate ionic liquid under microwave irradiation conditions. Antimicrobial, antioxidant, and toxicity studies displayed various biological activities depending on structure of the pyrans.

Liquid-liquid equilibrium data for extractive desulfurization using 1-butyl-3-methyl imidazolium thiocyanate, n-alkane and thiophene

The experimental liquid – liquid equilibrium (LLE) data for three ternary mixtures containing an ionic liquid (IL) (1-butyl-3-methyl imidazolium thiocyanate [Bmim][SCN]), alkanes (n-hexane, n-octane and n-decane) and sulfur compound (thiophene) have been measured experimentally. Distribution and selectivity coefficients have been calculated using experimental data. The LLE data have been obtained at 25 °C and ambient pressure. The experimental LLE data of ternary mixtures have been compared with our previous works. It has been shown that the IL with higher molecular weight of cation has higher solute distribution and lower selectivity coefficients. It has been found that the solubility decreases as the cation length decreases, meanwhile ILs cation chain length has a remarkable effect on solubility of alkanes. Moreover, the experimental data have been demonstrated that the selectivity decreases as alkane chain length of alkane decreases while the solubility of alkanes in the ILs increases, hence the removal costs of aromatic sulfur components will be increased. The results show that [Bmim][SCN] has the lowest alkane solubility and highest selectivity coefficient, in the system containing n-decane and thiophene. A comparative study reveals that compared to other ILs, [Bmim][SCN] is a more suitable solvent. Finally, the experimental data have been correlated utilizing non-randomness two liquid (NRTL) model. The binary energy parameters were obtained, it can be seen that the model can correlate the experimental data efficiently.

A new theoretical model – The ionic molar surface Gibbs free energy and its application

Three novel ether-functionalized ionic liquids (ILs) 1-ethyl-3-(2-methoxyethyl)-imidazolium acetate, [C22O1IM][OAc], 1-ethyl-3-(2-methoxyethyl)-imidazolium thiocyanate, [C22O1IM][SCN], 1-ethyl-3-(2-methoxyethyl)-imidazolium trifluoromethanesulfonate, [C22O1IM][TfO], and two ILs 1-ethyl-3-(2-methoxyethyl)-imidazolium dicyanamide, [C22O1IM][DCA], 1-ethyl-3-(2-methoxyethyl)-imidazolium bis(trifluoromethylsulfonyl)imide, [C22O1IM][NTF2] were prepared and characterized. Their density and surface tension were measured at T=(298.15–338.15)K. As a new theoretical model, the ionic molar surface Gibbs free energy, gi, was put forward. The ionic molar surface Gibbs free energy, g−, for [BF4]−, which was as reference ion, was obtained in terms of the extrathermodynamic assumptions so that the ionic molar surface Gibbs free energy, g+, of the corresponding cations, [Cnmim]+ (n=2–6), were determined. In terms of the g+ values of [Cnmim]+ (n=2–6), the g− values of 12 kinds of anions were determined and then the average g+ value of [C22O1IM]+ (9.52±0.21kJ·mol−1) was gotten. By using the values of these gi, the predicted values of molar surface Gibbs free energy, gest, and surface tension, γest, for [C22O1IM][X] (X=OAC, SCN, DCA, TfO, NTF2) and other 45 ionic liquids were estimated. In comparison, the predicted values correlated quite well with their matching experimental values.

Effect of task specific thiocyanate based ionic liquids on relative volatility of cyclohexane and benzene azeotropic mixture

The relative volatilities of cyclohexane (Cy) to benzene (Bz) in the presence of eight task-specific imidazolium thiocyanate ionic liquids (ILs) were measured using headspace gas chromatography. The ILs contain nitrile, ally, benzyl and hydroxyl functional group in their imidazolium cations and thiocyanate as anion. The effects of incorporation of nitrile, allyl, benzyl and hydroxyl functional groups in imidazolium alkyl chain on the relative volatility of Cy to Bz were investigated using experiment and quantum calculations. COSMO-RS model was used to study the polarity (charge distribution) of the ILs and the solutes. Density functional theory (DFT) was employed to investigate the cation-anion interaction energies and IL-Bz/Cy binding energies. The structural variations of the imidazolium cation influence the performance of the ILs. Moreover, the performances of the ILs were compared with two typical conventional entrainers, dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF). Except two hydroxyl containing ILs, the remaining six ILs show higher Cy to Bz relative volatility values compared to the bench marked conventional solvents.

Preparation and properties of titania based ionogels synthesized using ionic liquid 1-ethyl-3-methyl imidazolium thiocyanate

Present study reports the synthesis of titania (TiO2) based ionogels using ionic liquid (IL) 1-ethyl-3-methyl imidazolium thiocyanate ([EMIM][SCN]) by non-aqueous sol-gel process. Ionogels are characterized using N2 adsorption-desorption, TGA, DSC, SEM, TEM, XRD, and FTIR. N2-sorption results show that TiO2 matrices have meso-pores with uniform pore size distribution. Thermal studies reveal that thermal stability of confined IL decreases while the glass transition temperature (Tg) is found to increase. XRD patterns show that IL containing TiO2 matrices exhibit amorphous (weak crystalline peaks) nature however after extraction of IL from ionogel, it shows the crystalline (anatase) phase of TiO2 which has also been found from SAED pattern. SEM micrographs reveal that as the amount of IL is increased, TiO2 particles are found to agglomerate. FTIR results indicate that the vibrational frequencies of confined IL are found to shift due to interaction of IL molecules with titania pore wall surface.

Evaluation of Thermophysical Properties of Functionalized Imidazolium Thiocyanate Based Ionic Liquids

New cyano-based ionic liquids with thiocyanate anion and nitrile, ally, benzyl, and hydroxyl functionalized imidazolium cations were prepared, and some of their important thermophysical properties were measured. Properties such as density, viscosity, and refractive index were measured over various temperature ranges. From the experimental density values, the molecular volume, standard molar entropy, lattice energy, and thermal expansion coefficient of the ionic liquids were calculated. The thermal stabilities of the ionic liquids were investigated using thermogravimetric analysis. The effects of functionalized imidazolium side chains on the thermophysical properties of the ionic liquids were investigated. Density functional theory calculations were performed to study the effect of the structural variation of the imidazolium cation on properties of the ionic liquids.

Reactions of 2-aminothiphenols with chalcones in an ionic liquid medium: a chemoselective catalyst-free synthesis of 1,5-benzothiazepines

A series of 2,4-disubstituted derivatives of 1,5-benzothiazepines were prepared via a one-pot thia-Michael-cyclization sequence by the reaction of various 2-aminothiophenols with chalcones in ionic liquid media. The choice of the ionic liquid had a significant impact on the process. In the case of 1-octyl-3-methyl imidazolium thiocyanate ([omim]SCN), both steps took place in one pot to give substituted 1,5-benzothiazepines. However, only a simple thia-Michael addition could occur in 1-octyl-3-methyl imidazolium chloride ([omim]Cl) medium. Reactions were catalyst free and could tolerate the presence of different functional groups. The workup procedure was facile and the ionic liquid could be recycled at least seven times in a row.

Effects of ionic liquid mixtures on lipid extraction from Chlorella vulgaris

In this study, pre-biodiesel-production lipid extraction from microalgae (Chlorella vulgaris) was performed. The yield-enhancing effects of ionic liquid blends on the lipid extraction were investigated. The initial fatty acids content of the C. vulgaris was 292.2 mg/g cell. The lipid extraction yield using single ionic liquids was compared with the yield obtained with organic solvents and ionic liquid mixtures, respectively. The yield by hexane–methanol solvent was 185.4 mg/g cell. Among the 12 ionic liquids, 1-ethyl-3-methyl imidazolium acetate, 1-ethyl-3-methyl imidazolium diethylphosphate, 1-ethyl-3-methyl imidazolium tetrafluoroborate, and 1-ethyl-3-methyl imidazolium chloride showed high (>200.0 mg/g cell) lipid extraction yields. Although the yields of 1-ethyl-3-methyl imidazolium ethyl sulfate and 1-ethyl-3-methyl imidazolium thiocyanate were only 60.5 and 42.7 mg/g cell, respectively, the yield for their mixture (weight ratio of 1:1) was improved to 158.2 mg/g cell. Similarly, whereas the lipid extraction yield of 1-ethyl-3-methyl imidazolium hydrogen sulfate was just 35.2 mg/g cell, that for its mixture with 1-ethyl-3-methyl imidazolium thiocyanate (weight ratio of 1:1) was boosted to 200.6 mg/g cell. Overall, the synergistic effects of the ionic liquid mixtures with different anions improved the lipid extraction yield of C. vulgaris.

One-pot synthesis of nitrogen–sulfur-co-doped carbons with tunable composition using a simple isothiocyanate ionic liquid

The commercially available ionic liquid (IL) 1-ethyl-3-methyl imidazolium thiocyanate (Emim-scn) is used as a highly efficient precursor for the synthesis of nitrogen–sulfur-co-doped carbons. Mixtures with the ILs 1-ethyl-3-methyl-imidazolium dicyanamide (Emim-dca) and 1-butyl-3-methyl-pyridinium dicyanamide (Bmp-dca) enable tuning of the sulfur-content while the nitrogen incorporation is not hindered as such. The whole procedure is compatible with the salt templating process, enabling the synthesis of heterofunctional carbons with ultrahigh surface areas.

Phase equilibria study of the binary systems (ionic liquid + thiophene): Desulphurization process

(Solid + liquid) equilibria (SLE) and (liquid + liquid) equilibria (LLE) for the binary systems: {ionic liquid (IL) N-butyl-4-methylpyridinium tosylate ( p-toluenesulfonate) [BM 4Py][TOS], or N-butyl-3-methylpyridinium tosylate [BM 3Py][TOS], or N-hexyl-3-methylpyridinium tosylate [HM 3Py][TOS], or N-butyl-4-methylpyridinium bis{(trifluoromethyl)sulfonyl}imide [BM 4Py][NTf 2], or 1,4-dimethylpyridinium tosylate [M 1,4Py][TOS], or 2,4,6-collidine tosylate [M 2,4,6Py][TOS], or 1-ethyl-3-methylimidazolium thiocyanate [EMIM][SCN], or 1-butyl-3-methylimidazolium thiocyanate [BMIM][SCN], or 1-hexyl-3-methylimidazolium thiocyanate [HMIM][SCN], or triethylsulphonium bis(trifluoromethylsulfonyl)imide [Et 3S][NTf 2] + thiophene} have been determined at ambient pressure. A dynamic method was used over a broad range of mole fractions and temperatures from (270 to 390) K. In the case of systems (pyridinium IL, or sulphonium IL + thiophene) the mutual immiscibility with an upper critical solution temperature (UCST) was detected at the very narrow and low mole fraction of the IL. For the binary systems containing (imidazolium thiocyanate IL + thiophene), the mutual immiscibility with the lower critical solution temperature (LCST) was detected at the higher mole fraction range of the IL. The basic thermal properties of the pure ILs, i.e. melting and glass-transition temperatures as well as the enthalpy of fusion have been measured using a differential scanning microcalorimetry technique (DSC). The well-known NRTL equation has been used to correlate experimental SLE/LLE data sets.

A nanoporous TiO2 electrode and new ionic liquid doped solid polymer electrolyte for dye sensitized solar cellapplication

Nanocrystalline TiO2 films with nanosized pores have been synthesized using the doctor-blade method. A newkind of low-viscosity ionic liquid (1-ethyl 3-methyl imidazolium thiocyanate) doped solidelectrolyte (using polyethylene oxide, PEO, as host) (ILSE) has been examined andsandwiched between the aforesaid electrode and counter-electrode. The structural, electricaland photo-electrochemical characterization of ILSE is reported in this paper. It isobserved that the doping of ionic liquid (IL) has improved the ionic conductivityand the efficiency of the solar cells fabricated using this ILSE. The photovoltaicperformance of a dye sensitized solar cell using solid ILSE film is also discussed.

Versatile preparation method for mesoporous TiO2 electrodes suitable for solid-state dye sensitized photocells

Nano-structured TiO2 electrodes, suitable for dye sensitized solid-state solar cells were prepared by a new simple spraying technique (SPT). Physical properties of these electrodes were compared with the electrodes prepared by the ‘doctor blade’ technique (typical sliding method, DB). Dye sensitized solid-state solar cells, comprising of CuI as the hole conductor, were fabricated with these electrodes and enhanced photo responses were obtained with SPT electrodes. The effects of additives, either to the spray solution or to the hole conductor on the photoresponses of the above devices were also studied. The cells fabricated with SPT electrodes containing Al(BuiO)3 showed ∼ 2.4% efficiency and addition of 1-ethyl-3-methyl imidazolium thiocyanate into CuI layer further enhanced the efficiency up to 2.75% under the irradiance of 100 mW cm−2 (AM 1.5).