The thermal stabilities of 66 ionic liquids (ILs) were investigated using the thermogravimetric analysis (TGA) method. Isothermal TGA studies on the ILs showed that ILs exhibit decomposition at temperatures lower than the onset decomposition temperature (Tonset), which is determined from ramped temperature TGA experiments. Thermal decomposition kinetics of ILs was analyzed using pseudo-zero-order rate expression and their activation energy was obtained. Parameter T0.01/10h, the temperature at which 1% mass loss occurs in 10 h, was used to evaluate the long-term thermal stability of ILs. The thermal stability of the ILs was classified to five levels according to Tonset. The ILs thermal stability is dependent on the structure of ILs, i.e., cation modification, cation and anion type. The correlations between the stability and the hydrophilicity of ILs were discussed. Finally, the thermal stabilities of acetate-based ILs, amino acid ILs, and dicyanamide ILs were analyzed.

http://pubs.acs.org/doi/pdf/10.1021/ie5009597

Comprehensive Investigation on the Thermal Stability of 66 Ionic Liquids by Thermogravimetric Analysis

Solvatochromic parameters for solvents of interest in green chemistry

Our OPLS-2009IL force field parameters (J. Chem. Theory Comput. 2009, 5, 1038–1050) were originally developed and tested on 68 unique ionic liquids featuring the 1-alkyl-3-methylimidazolium [RMIM], N-alkylpyridinium [RPyr], and choline cations. Experimental validation was limited to densities and a few, largely conflicting, heat of vaporization (ΔHvap) values reported in the literature at the time. Owing to the use of Monte Carlo as our sampling technique, it was also not possible to investigate the reproduction of dynamics. The [RMIM] OPLS-2009IL parameters have been revisited in this work and adapted for use in molecular dynamics (MD) simulations. In addition, new OPLS-AA parameters have been developed for multiple anions, i.e., AlCl4–, BF4–, Br–, Cl–, NO3–, PF6–, acetate, benzoate bis(pentafluoroethylsulfonyl)amide, bis(trifluoroethylsulfonyl)amide, dicyanamide, formate, methylsulfate, perchlorate, propanoate, thiocyanate, tricyanomethanide, and trifluoromethanesulfonate. The computed solvent densities...

Revisiting OPLS Force Field Parameters for Ionic Liquid Simulations

Novel chitosan films with laponite immobilized Ag nanoparticles for active food packaging.

Ionic liquids in the processing and chemical modification of chitin and chitosan for biomedical applications

Influence of anionic structure on the dissolution of chitosan in 1-butyl-3-methylimidazolium-based ionic liquids

Carboxylate-anion-based imidazolium ionic liquids (ILs) are powerful solvents for cellulose and lignin. However, little is known about their fundamental physicochemical properties. In this work, 1-butyl-3-methylimidazolium carboxylate ILs 1-butyl-3-methylimidazolium formate ([C4mim][HCOO]), acetate ([C4mim][CH3COO]), propionate ([C4mim][CH3CH2COO]), and butyrate ([C4mim][CH3(CH2)2COO]), in which the alkyl chain length in the anions is being varied in contrast to the more usual studies where alkyl chain length in the cations is varied, have been synthesized and their densities and surface tensions have been determined experimentally at different temperatures. By using these data, the molar volume, isobaric expansivity, standard entropy, lattice energy, surface excess entropy, vaporization enthalpy, and Hildebrand solubility parameter have been estimated for these ILs. From the analysis of structure–property relationship, the effect of alkyl chain length in the anions on these physicochemical properties of ...

Effect of Alkyl Chain Length in Anions on Thermodynamic and Surface Properties of 1-Butyl-3-methylimidazolium Carboxylate Ionic Liquids

Enhancement of uranium(VI) biomineralization by Saccharomyces cerevisiae through addition of inorganic phosphorus

Chemotherapeutics occupy a pivotal role in the medication of different types of cancers, but the prevalence and mortality rates of cancer remain high. The drug resistance and low specificity of current available chemotherapeutics are the main barriers for the effective cancer chemotherapy, evoking an immediate need for the development of novel anticancer agents. Pyrazole is a highly versatile five-membered heterocycle with two adjacent nitrogen atoms and possesses remarkable therapeutic effects and robust pharmacological potency. The pyrazole derivatives especially pyrazole hybrids have demonstrated potent in vitro and in vivo efficacies against cancers through multiple mechanisms, inclusive of apoptosis induction, autophagy regulation, and cell cycle disruption. Moreover, several pyrazole hybrids such as crizotanib (pyrazole-pyridine hybrid), erdafitinib (pyrazole-quinoxaline hybrid) and ruxolitinib (pyrazole-pyrrolo [2,3-d]pyrimidine hybrid) have already been approved for the cancer therapy, revealing that pyrazole hybrids are useful scaffolds to develop novel anticancer agents. The purpose of this review is to summarize the current scenario of pyrazole hybrids with potential in vivo anticancer efficacy along with mechanisms of action, toxicity, and pharmacokinetics, covering papers published in recent 5 years (2018-present), to facilitate further rational exploitation of more effective candidates. 

Qingtai Chen

Papers

Influence of anionic structure on the dissolution of chitosan in 1-butyl-3-methylimidazolium-based ionic liquids

Effect of Alkyl Chain Length in Anions on Thermodynamic and Surface Properties of 1-Butyl-3-methylimidazolium Carboxylate Ionic Liquids

Enhancement of uranium(VI) biomineralization by Saccharomyces cerevisiae through addition of inorganic phosphorus

Current scenario of pyrazole hybrids with in vivo therapeutic potential against cancers.