Ionic liquids (ILs) offer a wide range of promising applications because of their much enhanced properties. However, further development of such materials depends on the fundamental understanding of their hierarchical structures and behaviors, which requires multiscale strategies to provide coupling among various length scales. In this review, we first introduce the structures and properties of these typical ILs. Then, we introduce the multiscale modeling methods that have been applied to the ILs, covering from molecular scale (QM/MM), to mesoscale (CG, DPD), to macroscale (CFD for unit scale and thermodynamics COSMO-RS model and environmental assessment GD method for process scale). In the following section, we discuss in some detail their applications to the four scales of ILs, including molecular scale structures, mesoscale aggregates and dynamics, and unit scale reactor design and process design and optimization of typical IL applications. Finally, we address the concluding remarks of multiscale strat...

Multiscale Studies on Ionic Liquids

In order to protect the life of all creatures living in the environment, the toxicity arising from various hazardous chemicals must be controlled. This imposes a serious responsibility on different chemical, pharmaceutical, and other biological industries to produce less harmful chemicals. Among various international initiatives on harmful aspects of chemicals, the 'Green Chemistry' ideology appears to be one of the most highlighted concepts that focus on the use of eco-friendly chemicals. Ionic liquids are a comparatively new addition to the huge garrison of chemical compounds released from the industry. Extensive research on ionic liquids in the past decade has shown them to be highly useful chemicals with a good degree of thermal and chemical stability, appreciable task specificity and minimal environmental release resulting in a notion of 'green chemical'. However, studies have also shown that ionic liquids are not intrinsically non-toxic agents and can pose severe degree of toxicity as well as the risk of bioaccumulation depending upon their structural components. Moreover, ionic liquids possess issues of waste generation during synthesis as well as separation problems. Predictive quantitative structure-activity relationship (QSAR) models constitute a rational opportunity to explore the structural attributes of ionic liquids towards various physicochemical and toxicological endpoints and thereby leading to the design of environmentally more benevolent analogues with higher process selectivity. Such studies on ionic liquids have been less extensive compared to other industrial chemicals. The present review attempts to summarize different QSAR studies performed on these chemicals and also highlights the safety, health and environmental issues along with the application specificity on the dogma of 'green chemistry'.

Advances in QSPR/QSTR models of ionic liquids for the design of greener solvents of the future.

Chemometrics tools in QSAR/QSPR studies: A historical perspective

It is well known that heterocycles are among the most significant molecules for everyday life, ranging from natural products and bioactive substances to functional materials This review will focus on the synthesis of heterocycles by reactions involving elemental sulfur published from 2017 until now

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Recent Advances in the Synthesis of Heterocycles via Reactions Involving Elemental Sulfur

Thermal stability and thermal decomposition kinetics of 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) were investigated using isothermal and non-isothermal thermo-gravimetric analysis. The results indicated that isothermal test in the air showed that after storage at 180 and 300 °C both for 10 h, the conversion rate of [bmim]BF4 was 1.28 and 2.57 %, respectively. When stored at less than 300 °C, all bands of IR spectra are nearly unchanged. It suggests that [bmim]BF4 basically is stable. When isothermal stored at 350 °C for 2 h, the ATR–FTIR spectra show that the relative intensity of BF
 4
 −1
 anion near band of 1058 cm−1 fell by 36.7 %. Due to the intensity of the absorption band declined significantly in the range of 300–350 °C, the anion of BF
 4
 −1
 was possibly dissociated by the action of air and heat; thus, at the time [bmim]BF4 is not stable. The average apparent activation energy of thermal degradation obtained by multiple scanning methods is 105.6 kJ mol−1. Moreover, mass spectrometric analysis also shows that the z/m of [bmim+] is 139.1; in the thermal degradation process, the possibility of generating a dimer between imidazolium cation exists.

Thermal stability of imidazolium-based ionic liquids investigated by TG and FTIR techniques

Glass transition temperature is one of the main criteria for the evaluation of the potential options for electrolyte application. In this communication, the attention was focused on the prediction of glass transition temperature of 1,3-dialkyl imidazolium ionic liquids which could be considered as potential future electrolytes. For this purpose, the quantitative structure–property relationship (QSPR) method is employed to develop two models for determination of glass transition temperature. In this study, both anion and cation descriptors are taken into account for model development. In the first part of this study, genetic function approximation is applied for model’s parameter selection. In order to study the nonlinear relations between the selected molecular descriptors and the glass transition temperature, least square support vector machines (LSSVM) was successfully applied in second part of this study. Furthermore, the genetic algorithm (GA) optimization methods are respectively implemented to optimize the LSSVM model parameters. Consequently, we obtain two predictive models with satisfactory results qualified by the following statistical parameters: absolute average deviations of the predicted properties from existing experimental values by the GFA linear equation: 2.68%, squared correlation coefficient: 0.91 and root mean square : 5.717 K and 1.38% and 0.97 and 4.05 K evaluated by the LSSVM–QSPR model, respectively.

A predictive quantitative structure–property relationship for glass transition temperature of 1,3-dialkyl imidazolium ionic liquids : Part 2. The nonlinear approach ()

Glass transition temperature is one of the main criteria for the evaluation of the potential options for electrolyte application. In this communication, the attention was focused on the prediction of glass transition temperature of 1,3-dialkyl imidazolium ionic liquids which could be considered as potential future electrolytes. For this purpose, the quantitative structure–property relationship (QSPR) method is employed to develop two models for determination of glass transition temperature. In this study, both anion and cation descriptors are taken into account for model development. In the first part of this study, genetic function approximation is applied for model’s parameter selection. In order to study the nonlinear relations between the selected molecular descriptors and the glass transition temperature, least square support vector machines (LSSVM) was successfully applied in second part of this study. Furthermore, the genetic algorithm (GA) optimization methods are respectively implemented to optimize the LSSVM model parameters. Consequently, we obtain two predictive models with satisfactory results qualified by the following statistical parameters: absolute average deviations of the predicted properties from existing experimental values by the GFA linear equation: 2.68%, squared correlation coefficient: 0.91 and root mean square : 5.717 K and 1.38% and 0.97 and 4.05 K evaluated by the LSSVM–QSPR model, respectively.

A predictive quantitative structure–property relationship for glass transition temperature of 1,3-dialkyl imidazolium ionic liquids

Copper or silver salts promote a domino addition–cyclization reaction between terminal alkynes, carbon disulfide, and oxiranes in a regioselective manner to afford 1,4-oxathiane derivatives in good yield.

Copper-Catalyzed Domino Addition–Cyclization Reaction between Terminal Alkynes, Carbon Disulfide, and Oxiranes

Unsymmetrical piperazines are key constituents of many pharmaceuticals. Given that the selective introduction of an aryl and alkyl motif onto the piperazine is not always straightforward, direct arylation and alkenylation of 1,4-diaza-bicyclo[2.2.2]octane would obviate the inefficiencies associated with the preparation of these target molecules. We have utilized alkyl halides, aryl or alkenyl triflates, and 1,4-diaza-bicyclo[2.2.2]octane for the synthesis of N-alkyl-N′-aryl or alkenylpiperazines. The optimum conditions are developed using CuCl, t-BuOLi in NMP. Alkenyl triflates requires N, N′-dimethyl ethylenediamine and higher temperature to afford the desired cross-coupled product. Substrates bearing electron-deficient and electron-rich groups were successfully coupled under the optimum reaction conditions.

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Synthesis of N‐alkyl‐N′‐aryl or Alkenylpiperazines: A Copper‐Catalyzed C–N Cross‐Coupling in the Presence of Aryl and Alkenyl Triflates and DABCO

An efficient multicomponent reaction of nitroalkanes and elemental sulfur with oxiranes was developed with the aid of silver salt. This reaction procedure provides a novel and practical strategy for the rapid assembly of 1,3-oxathiolane skeletons. The reaction exhibited remarkable functional group tolerability and regio-selectivity so that only one regio-isomer formed during the ring opening of oxiranes.

Seyed Mahmoud Mousavi-Safavi

Papers

A predictive quantitative structure–property relationship for glass transition temperature of 1,3-dialkyl imidazolium ionic liquids : Part 2. The nonlinear approach ()

A predictive quantitative structure–property relationship for glass transition temperature of 1,3-dialkyl imidazolium ionic liquids

Copper-Catalyzed Domino Addition–Cyclization Reaction between Terminal Alkynes, Carbon Disulfide, and Oxiranes

Synthesis of N‐alkyl‐N′‐aryl or Alkenylpiperazines: A Copper‐Catalyzed C–N Cross‐Coupling in the Presence of Aryl and Alkenyl Triflates and DABCO

Catalytic multicomponent reaction between nitroalkanes, elemental sulfur, and oxiranes