The structure and properties of niobapyrimidinium complex were examined by density functionaltheory method (mpw1pw91). The effect of solvent on the structural parameters, frontier orbitalenergies and hyperpolarizability (tot) of this molecule has been explored. The thermodynamicproperties of the title compound at different temperatures have been calculated. Also, the parasubstitutionseffect on ...

The chemical equilibria concerning formic acid are computationally investigated in water over a wide range of thermodynamic conditions. The solvation free energies for relevant C1 compounds are evaluated in the method of energy representation, and are used to assess the solvent effect on the formic acid reactions. In the two competitive decomposition processes of formic acid, the solvent strong...

We discuss the effects of the solvent composition on the helix-coil transition of a polypeptide chain. We use a simple model to demonstrate that improving the hydrogen-bonding ability of the solvent can make the transition less cooperative, without affecting the transition temperature. This effect is very different from other solvent effects which primarily influence the melting transition rath...

The effective interactions between two test counterions and two test solvent dipoles in a semidilute/concentrated weakly charged polyelectrolyte solution are studied using the field-theoretical approach on the mean-field level. From the effective Hamiltonians in terms of the two test counterions and the two test solvent dipoles, respectively, analytical expressions for the effective interaction...

The equilibrium properties of a tangent-hard-sphere polymer chain in a hard sphere monomer solvent are studied using a Born-Green-Yvon integral equation in conjunction with a two-site solvation potential. The solvation potential is constructed using low density results for a hard-sphere trimer in a hard sphere solvent. The BGY equation has been solved for polymers of lengths up to 100 for a ran...

Recently in this laboratory the conductometric measurement of aqueous solutions Li, Na and K salt L-leucine were studied at different temperature molar concentration to investigate solute-solvent, ion-solvent interactions (solute means drug) also effect dilution was investigated. During work thermodynamic parameters (change free energy, change entropy enthalpy) investigated concentrations range...

Dimethylformamide (DMF) is widely used as a drug solvent. We found DMF to have wide-spread pharmacological effects including depressant effect on CNS evidenced by a decrease in locomotor activity, body and limb tone and rectal temperature, and potentiation of pentobarbitone sleep. A dose-dependent hypotensive effect was seen in cats and rats. In rats, it was partially blocked by atropine and wa...

The effect of carbon black on the mechanical properties of elastomers is of great interest, because the filler is one of principal ingredients for the manufacturing of rubber products. While fillers can be used to enhance the properties of elastomers, including stress-free swelling resistance in solvent, it is widely known that the introduction of fillers yields significant inelastic responses ...