A parametrization methodology for evaluating the solvation free energy, using the polarizable continuum model implemented in Gamess software, is presented in a formulation which makes use of a group contribution conception to construct the cavities. The systems studied include alkanes, alcohols, aldehydes and ketones embeded in a continuous medium simulating the water as the solvent. For each family, the CH2, OH, and C=O moieties of atoms are put together in single spheres forming a group. The cavities are constructed in two different ways, one for the electrostatic component and the other for nonelectrostatic contributions, i.e., the cavitation, dispersion, and repulsion components of free energy of solvation. A multivariate analysis is performed to obtain an assembly of variables, for each homologous series, able to give the results which are close to experiment. The analysis is addressed in order to (i) compare the theoretical free energy of solvation with the experimental trends of the solutes in aqueous media, when the chain is increased, (ii) compare the behavior of each component of free energy with the increasing CH2 number, (iii) investigate the influence of the oxygen atom on the components, and (iv) quantify the relative contribution of each component to the final free energy of solvation for some homologous series.
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http://dx.doi.org/10.1021/jp053520v | DOI Listing |
Phys Chem Chem Phys
January 2025
Chemistry Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.
The present study focuses on designing mutant peptides derived from the lanthanide binding tag (LBT) to enhance selectivity for trivalent actinide (An) ions over lanthanide (Ln) metal ions (M). The LBT is a short peptide consisting of only 17 amino acids, and is known for its high affinity towards Ln. LBT was modified by substituting hard-donor ligands like asparagine (ASN or N) and aspartic acid (ASP or D) with softer ligand cysteine (CYS or C) to create four mutant peptides: M-LBT (wild-type), M-N103C, M-D105C, and M-N103C-D105C.
View Article and Find Full Text PDFNanoscale Horiz
January 2025
Department of Chemical Engineering, Hampton University, Hampton, VA 23668, USA.
In this work, we use experimental and theoretical techniques to study the origin of the boosted hydrogen evolution reaction (HER) catalytic activity of two pyridyl-pyrrolidine functionalized C fullerenes. Notably, the mono-(pyridyl-pyrrolidine) penta-adduct of C has exhibited a remarkable HER catalytic activity as a metal-free catalyst, delivering an overpotential () of 75 mV RHE and a very low onset potential of -45 mV RHE. This work addresses fundamental questions about how functionalization on C changes the electron density on fullerene cages for high-performance HER electrocatalysis.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Institute of Metal Physics, Russian Academy of Sciences-Ural Division, 620990 Yekaterinburg, Russia.
The crystal and electronic structure of ZrxTi1-xSe2 (0 < x < 1) compounds and their electrical resistivity have been studied in detail for the first time. A combination of soft x-ray spectroscopic methods (XPS, XAS, and ResPES) was used to investigate the electronic structure. The lattice parameters as a function of the metal concentration x obey Vegard's law.
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Computer-aided drug discovery (CADD) utilizes computational methods to accelerate the identification and optimization of potential drug candidates. Free energy perturbation (FEP) and thermodynamic integration (TI) play a critical role in predicting differences in protein binding affinities between drug molecules. Here, we implement SPONGE-FEP, which incorporates selective integrated tempering sampling (SITS) to enhance sampling efficiency and contains an automated workflow for relative binding free energy (RBFE) calculations.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Experimental Center of Advanced Materials, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China.
In this study, employing a simple anion exchange strategy and straightforward three-step synthetic route, a pair of promising nitrogen-rich heterocyclic cation and oxygen-rich anion were assembled together to generate two novel dinitramide energetic salts, both of which exhibit prominent detonation performance comparable to benchmark explosive RDX while possessing significantly lower mechanical sensitivity than RDX, thereby highlighting them as promising candidates for advanced secondary explosives. This work has directly led to a practical protocol for the design of chloride-free environmentally friendly IEMs, and accelerates the development of organic explosives with high-energy and low-sensitivity.
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