Synthesis, conformational studies, vibrational spectra and thermal properties, of new 1,4-(phenylenebis(methylene) bis(methyl-imidazolium) ionic liquids

Developing Advanced Antibacterial Alginic Acid Biomaterials through Dual Functionalization

This paper delves into the intersection of biomaterials and antibacterial agents, highlighting the importance of alginic acid-based biomaterials. We investigate enhancing antibacterial properties by functionalizing alginic acid with an ionic liquid and a potent chelating agent, tris(hydroxypyridinone) (THP). Initial functionalization with the ionic liquid markedly improves the material's antibacterial efficacy. Subsequent functionalization with THP further enhances this activity, reducing the minimum inhibitory concentration from 6 to 3 mg/mL. Notably, the newly developed dual-functionalized materials exhibit no cytotoxic effects at the concentrations tested, underscoring their potential for safe and effective antibacterial applications. These findings highlight the promising role of dual-functionalized alginic acid biomaterials in developing advanced antibacterial treatments.

Spectroscopic Evidence of Localized Small Polarons in Low-Dimensional Ionic Liquid Lead-Free Hybrid Perovskites

Rational design is an important approach to consider in the development of low-dimensional hybrid organic-inorganic perovskites (HOIPs). In this study, 1-butyl-1-methyl pyrrolidinium (BMP), 1-(3-aminopropyl)imidazole (API), and 1-butyl-3-methyl imidazolium (BMI) serve as prototypical ionic liquid components in bismuth-based HOIPs. Element-sensitive X-ray absorption spectroscopy measurements of BMPBiBr4 and APIBiBr5 reveal distinct resonant excitation profiles across the N K-edges, where contrasting peak shifts are observed. These 1D-HOIPs exhibit a large Stokes shift due to the small polaron contribution, as probed by photoluminescence spectroscopy at room temperature. Interestingly, the incorporation of a small fraction of tin (Sn) into the APIBiBr5 (Sn/Bi mole ratio of 1:3) structure demonstrates a strong spectral weight transfer accompanied by a fast decay lifetime (2.6 ns). These phenomena are the direct result of Sn-substitution in APIBiBr5, decreasing the small polaron effect. By changing the active ionic liquid, the electronic interactions and optical responses can be moderately tuned by alteration of their intermolecular interaction between the semiconducting inorganic layers and organic moieties.

Electronic, optical and spectroscopic properties of N-dialkyl-imidazolium hexafluorophosphate (CNMIM.PF6) ionic liquid crystal molecules investigated by computational methods

In this present work, we calculate the electronic, spectroscopic and nonlinear optical properties (NLO) of N-dialkyl-imidazolium hexafluorophosphate (CNMIM.PF6, where N = 10, 12, 14, 16, 18, 20) ionic liquid crystal molecules under the effect of alkyl chain length variation in cation moiety [CNMIM]+ with fixed anion [PF6]-. CONTEXT: The majority of research on ionic liquid crystal to date has been focused on experiments, while theoretical studies on the optical properties of ionic liquid crystal have been extremely rare. Nonlinear phenomena in optical devices have attracted many researchers. Therefore, results of NLO properties may favor facile synthesis and fabrication of novel-type of materials as well as optoelectronic devices. Spectroscopic studies elucidate further insight into ionic liquid crystal behavior. The results demonstrate that variations in alkyl chain length have an impact on the conformers' electrical, spectroscopic, and NLO properties as well as their stability. The stability of ionic liquid crystal molecules increases with increase in the alkyl chain length and the energy band gap range is 6.64-6.29 eV. Understanding ionic liquid crystal's physical behavior requires an understanding of their dipole moments and NLO features, which are covered in this article. The results of NLO characteristics for all ionic liquid crystal molecules show that their first-order hyperpolarizabilities are higher than the reference molecule (urea). METHODS: The electronic (molecular energy band gap, electrostatic potential map, as well as HOMO-LUMO orbitals) and spectroscopic (IR-RAMAN, UV) properties were evaluated with the help of theoretical model at B3LYP/6-31G(d) while the NLO study has been performed using B3LYP and M06-2X with different basis sets 6-31G(d) and 6-311++G(d,p), as implemented in Gaussian09 software.

Characteristics of ignition delay of hypergolic ionic liquids combined with 1-amino-4-methylpiperazine

The ignition delay time of the hypergolic ionic liquids, 1-ethyl-3-methylimidazolium dicyanamide [EMIM][C₂N₃] and 1,3-dimethyl imidazolium dicyandiamide [DMIM][C₂N₃], can be controlled to approximately 20 ms by adding 1-amino-4-methylpiperazine while keeping the vapor pressure below 1 torr at 298 K.

Elaboration and Characterization of Natural Deep Eutectic Solvents (NADESs): Application in the Extraction of Phenolic Compounds from pitaya

In this paper, natural deep eutectic solvents (NADESs) with lactic acid, glycine, ammonium acetate, sodium acetate, and choline chloride were prepared with and without the addition of water. NADES formation was evaluated using FTIR and Raman, where hydrogen bonds were identified between the hydroxyl group of lactic acid and the amino and carboxyl groups of glycine. Acetate and ammonium ions were also identified as forming bonds with lactic acid. The addition of water did not cause changes in the vibrational modes of the FTIR and Raman spectra but contributed to a reduction in NADES viscosity and density. Viscosity ranged from 0.335 to 0.017 Pa s^-1, and density ranged from 1.159 to 0.785 g mL^-1. The best results for the extraction of phenolic compounds from pitaya (dragon fruit) were achieved with an organic solvent (450. 41 mg 100 g^-1 dry bases-db) in comparison to NADESs lactic acid:glycine (193.18 mg 100 g^-1 db) and lactic acid:ammonium acetate (186.08 mg 100 g^-1 db). The antioxidant activity of the extracts obtained with the NADESs was not statistically different from that of the extract obtained with organic solvents.

Thermal Kinetics of Monocationic and Dicationic Pyrrolidinium-Based Ionic Liquids

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 (E_a) 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 E_a 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 E_a and log A of ILs are strongly related to the thermal stability of ILs.