ABSTRACT
An acute toxicity study assessed the LC50 values for eight different amino acid ionic liquids (AAILs), featuring two cations, tetrabutylphosphonium [P4444] and tetrabutylammonium [N4444], coupled with four anions [PHE], [ASP], [SER], and [GLY]. According to the OECD 203 standard for acute fish toxicity tests with guppy fish (Poecilia reticulata, all the AAILs exhibited low toxicity levels, and were practically nontoxic and harmless. The LC50 values surpassed 100â¯mg/L and 1000â¯mg/L. This study provides valuable insights for industrial professionals in utilizing tetrabutylphosphonium-based amino acid ionic liquids [P4444] [AA] and tetrabutylammonium-based amino acid ionic liquids [N4444][AA] in chemical processes, indicating their safety in aquatic environments. These promising results highlight the potential of incorporating these AAILs into diverse chemical processes while ensuring minimal ecological impact.
ABSTRACT
This work presents an in-depth kinetic thermal degradation comparison between traditional monocationic and the newly developed dicationic ionic liquid (IL), both coupled with a bromide (Br-) anion by using non-isothermal thermogravimetric analysis. Thermal analyses of 1-butyl-1-methylpyrrolidinium bromide [C4MPyr][Br] and 1,4-bis(1-methylpyrrolidinium-1-yl)butane dibromide [BisC4MPyr][Br2] were conducted at a temperature range of 50-650 °C and subjected to various heating rates, which are 5, 10, 15, 20 and 25 °C/min. Thermogravimetric analysis revealed that dicationic IL, [BisC4MPyr][Br2] is less thermally stable compared to monocationic [C4MPyr][Br]. A detailed analysis of kinetic parameters, which are the activation energy (Ea) and pre-exponential factor (log A), was calculated by using Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO) and Starink. This study revealed that the average Ea and log A of [BisC4MPyr][Br2] are lower than [C4MPyr][Br], which may be contributed to by its low thermal stability. Conclusively, it proved that the Ea and log A of ILs are strongly related to the thermal stability of ILs.
ABSTRACT
The main mol-ecule of the title compound, C(2)H(8)N(+)·C(25)H(31)O(5) (-)·C(25)H(32)O(5)·0.5C(6)H(14)·H(2)O, exists as two crystallographically independent mol-ecules, the hydr-oxy group of one being deprotonated. The pyran rings of both independent units adopt boat conformations. One of the two cyclo-hexene rings of the xanthene unit adopts an envelope conformation whereas the other is in a half-chair conformation. The cyclo-hexene ring attached to the xanthene unit adopts an envelope conformation. The n-hexane solvent mol-ecule is disordered about a crystallographic glide plane and the symmetry-independent components are again disordered over two positions, each with an occupancy of 0.25. In the crystal structure, the xanthene derivatives are linked by O-Hâ¯O, N-Hâ¯O and C-Hâ¯O hydrogen bonds, forming a three-dimensional network with channels along the a axis. The dimethyl-ammonium cations and water mol-ecules lie in small channels and are linked to the framework via O-H.·O and N-Hâ¯O hydrogen bonds. The n-hexane solvent mol-ecules occupy large channels.
ABSTRACT
In the title compound, C(24)H(28)O(5), the two cyclo-hexene rings adopt envelope conformations, and the planes through the coplanar atoms makes dihedral angles of 82.86â (6) and 77.90â (6)° with the benzene ring. The two cyclo-hexene rings make a dihedral angle of 5.33â (6)° between their least-squares planes. The pyran ring adopts a flattened boat conformation. In the crystal packing, mol-ecules are linked into two-dimensional networks parallel to the ab plane via O-Hâ¯O and C-Hâ¯O inter-actions.
