The temperature dependence of the solvent reorganization energy for intramolecular electron transfer (ET) in acetonitrile is measured experimentally and calculated theoretically. The Stokes shifts for the charge transfer, optical transitions of (tetrahydro-4H-thiopyran-4-ylidene)propanedinitrile indicate that the solvent reorganization energy for ET decreases with temperature, whereas dielectri...

Extended Hildebrand solubility approach is used to estimate the solubility of nabumetone in binary solvent systems. The solubility of nabumetone in various propylene glycol-water mixtures was analyzed in terms of solute-solvent interactions using a modified version of Hildebrand-Scatchard treatment for regular solutions. The solubility of nabumetone in the binary solvent, propylene glycol-water...

Equilibria of the reaction of molybdenum(VI) with L-aspartic acid (Asp) and L- Glutamic acid(Glu) have been studied by spectrophotometric measurements in mixed solvent systems at an ionicstrength of 0.2 mol/dm3 sodium perchlorate, employed (15, 20, 25, 30± 0.1°C) at pH ranges of 3.2to 5.5 with a high ratio of ligand to metal. The stability constants of the complexes and theresulting free energy...

Carvedilol (CRV) is an important medicament for heart arrhythmia. The aim of this work was the interpretation of its vibrational spectra with consideration on the solvent effect. Infrared and Raman spectra were recorded in solid state as well in solution. The experimental spectra were evaluated using DFT quantum chemical calculations computing the optimized structure, atomic net charges, vibrat...

The Valence-Shell-Electron-Pair-Repulsion theory, in its Points-on-a-Sphere (POS) variant has been heretofore almost exclusively applied to molecular structure. It is shown that the POS model also implies the form of the potential energy surface for · bending deformations of molecules. The extent to which this elementary mechanical model simulates quantum mechanical interactions in binary compo...

The transition-state region of the I + HI reaction has been studied by photoelectron spectroscopy of IHIand IDI-. A well-resolved progression in the asymmetric stretch of the neutral IHI (IDI) complex is observed in each spectrum. These peaks apparently correspond to states of the complex that are unstable with respect to dissociation into I + HI (DI). The experimental peak positions, widths, a...

The transition state region of the reaction OH + H2 -. H2O + H is investigated by photoelectron spectroscopy of the H3Oand D30anions. The peaks observed in the spectra are from a combination of vibrational progressions and overlapping anion -. neutral electronic transitions. The photoelectron angular distributions indicate that two processes contribute to the spectra; these are assigned to phot...

in this work, we investigated the stability of molybdate-phosphonic acid (mpa) complex by density functionaltheory (dft) computations in six solvents with the dielectric constant ranging from 1.92 to 10.36. the methodsare used for calculations are b3lyp and b3pw9 i that have been studied in two series of basis sets: d95nand6-31+g (d,p) for hydrogen and oxygen atoms; lanl2dz for mo and phosphoru...

A large solvent polarity effect on the rate of singlet to triplet intersystem crossing (ksT) has been observed in the carbenes, diphenylcarbene (DPC) and dicycloheptadienylidene (DCHD)it is found that both ksT and the energy splitting (A&T) separtaing the singlet and triplet states decrease as the solvent polarity increases for the aromatic carbenes. This “inverse” gap effect, i.e. the time for...

We have coupled hybrid quantum mechanics (density functional theory; Car-Parrinello)/molecular mechanics molecular dynamics simulations to a grand-canonical scheme, to calculate the in situ redox potential of the Cu(2+) + e(-) --> Cu(+) half reaction in azurin from Pseudomonas aeruginosa. An accurate description at atomistic level of the environment surrounding the metal-binding site and finite...