Explosives properties of high energetic trinitrophenyl nitramide molecules: A DFT and AIM analysis

Structural and molecular properties of complexes of biomolecules and metal-organic frameworks: dispersion-corrected DFT treatment

Investigation of complexes of nanostructured materials and biomolecules has attracted much attention by various researchers as it can contribute to coherent growth and extended application of nanostructures in different technologies. In this research, following a comprehensive approach, we examined the interaction between different amino acids and metal-organic frameworks (MOFs) at atomic scale using computational chemistry. For this purpose, we employed the density functional theory (DFT-D2) calculations to afford a molecular description of the interaction properties of the amino acids and MOF-5 by examining the interaction energy and the electronic structure of the amino acid/MOF complexes. We found strong interactions between the amino acids and MOF through their polar groups as well as aromatic rings in the gas phase. However, our findings were significantly different in solvent media, where water molecules prevent the amino acids from approaching the active sites of MOF, causing weak attractions between them. The evaluation of nature of interaction between the amino acids and MOF by the atoms-in-molecules (AIM) theory shows that the electrostatic attractions are the main force contributing to bond formation between the interacting entities. Furthermore, our DFT-PBE model of theory was validated against the comprehensive MP2 quantum level of theory.

Theoretical insights into the cineole-based deep eutectic solvents

Deep eutectic solvents based on cineole as hydrogen bond acceptors and organic acids (succinic, malic, and lactic) as hydrogen bond donors are studied using a theoretical approach. The nature, strength, and extension of hydrogen bonding are analyzed, thus quantifying this prevailing interaction and its role in the fluid properties. Density functional theory was used to study small molecular clusters, and the topological characterization of the intermolecular forces was carried out using atoms in a molecule theory. Classical molecular dynamics simulations were considered to study nanoscopic bulk liquid properties and their relationship with relevant macroscopic properties such as density or thermal expansion. The reported results provide the characterization of environmentally friendly deep eutectic solvents and show the suitability of cineole for developing these sustainable materials.

Effect of Hydrogen Bond Donors and Acceptors on CO2 Absorption by Deep Eutectic Solvents

The effects of a hydrogen bond acceptor and hydrogen bond donor on carbon dioxide absorption via natural deep eutectic solvents were studied in this work. Naturally occurring non-toxic deep eutectic solvent constituents were considered; choline chloride, b-alanine, and betaine were selected as hydrogen bond acceptors; lactic acid, malic acid, and fructose were selected as hydrogen bond donors. Experimental gas absorption data were collected via experimental methods that uses gravimetric principles. Carbon dioxide capture data for an isolated hydrogen bond donor and hydrogen bond acceptor, as well as natural deep eutectic solvents, were collected. In addition to experimental data, a theoretical study using Density Functional Theory was carried out to analyze the properties of these fluids from the nanoscopic viewpoint and their relationship with the macroscopic behavior of the system, and its ability for carbon dioxide absorption. The combined experimental and theoretical reported approach work leads to valuable discussions on what is the effect of each hydrogen bond donor or acceptor, as well as how they influence the strength and stability of the carbon dioxide absorption in deep eutectic solvents. Theoretical calculations explained the experimental findings, and combined results showed the superiority of the hydrogen bond acceptor role in the gas absorption process, with deep eutectic solvents. Specifically, the cases in which choline chloride was used as hydrogen bond acceptor showed the highest absorption performance. Furthermore, it was observed that when malic acid was used as a hydrogen bond donor, it led to low carbon dioxide solubility performance in comparison to other studied deep eutectic solvents. The cases in which lactic acid was used as a hydrogen bond donor showed great absorption performance. In light of this work, more targeted, specific, deep eutectic solvents can be designed for effective and alternative carbon dioxide capture and management.

Quantum Chemistry Insight into the Interactions Between Deep Eutectic Solvents and SO2

A systematic research work on the rational design of task specific Deep Eutectic Solvents (DES) has been carried out via density functional theory (DFT) in order to increase knowledge on the key interaction parameters related to efficient SO₂ capture by DES at a molecular level. A total of 11 different DES structures, for which high SO₂ affinity and solubility is expected, have been selected in this work. SO₂ interactions in selected DES were investigated in detail through DFT simulations and this work has generated a valuable set of information about required factors at the molecular level to provide high SO₂ solubility in DES, which is crucial for enhancing the current efficiency of the SO₂ capture process and replacing the current state of the art with environmentally friendly solvents and eventually implementing these materials in the chemical industry. Results that were obtained from DFT calculations were used to deduce the details of the type and the intensity of the interaction between DES and SO₂ molecules at various interaction sites as well as to quantify short-range interactions by using various methods such as quantum theory of atoms in a molecule (QTAIM), electrostatic potentials (ESP) and reduced density gradients (RDG). Systematic research on the molecular interaction characterization between DES structures and SO₂ molecule increases our knowledge on the rational design of task-specific DES.

Design of arginine-based therapeutic deep eutectic solvents as drug solubilization vehicles for active pharmaceutical ingredients

The solvation of lidocaine in three newly designed deep eutectic solvents is studied using combined experimental and theoretical methods that include density functional theory and molecular dynamics methods. The intermolecular forces between lidocaine and the hydrogen bond acceptors and hydrogen bond donors of the deep eutectic solvents were analysed regarding the type and the strength of inter- and intra-molecular bonding. The structure, composition and properties of the lidocaine solvation shells are analysed together with the possible lidocaine-clustering around the studied deep eutectic solvents and their constituent molecules. Furthermore, the changes in the solvent structures upon lidocaine solubilization are also studied. Natural product-based eutectic solvents showed considerably high solvation of lidocaine in all three deep eutectics based on the strong solute-solvent intermolecular interactions accompanied by a slight volume expansion and minor solvent structural changes. These non-toxic and almost null-volatile therapeutic deep eutectic solvents can be considered as suitable solubilization media for developing pharmaceutical applications and they can be considered as effective drug delivery vehicles for active pharmaceutical ingredients.