Z. Naturforsch. 54 b, 193-199 (1999); received September 23, 1998 Solvation Structure, EXAFS, ab initio Molecular Orbital Method, Copper(I) Ion The structure parameters around the Cu(I) ion in pyridine (PY), 4-methylpyridine (4MPY), 2-methylpyridine (2MPY), 2,6-dimethylpyridine (26DMPY), and acetonitrile (AN) were de­ termined by the extended X-ray absorption fine structure (EXAFS) method. The ...

The effects of cosolvents on the solubility and hydration of small nonpolar solutes in solution has been investigated using a combination of molecular dynamics simulation and Widom particle insertion calculations. Results were obtained for helium, neon, argon, and methane solutes in solutions of sodium chloride, ammonium sulfate, calcium chloride, ammonium acetate, tetramethylammonium chloride,...

In this work, a numerical procedure based on the continuum model is developed and applied to the solvation energy for ground state and the spectral shift against the position and the orientation of the interfacial molecule. The interface is described as a sharp boundary separating two bulk media. The polarizable continuum model (PCM) allows us to account for both electrostatic and nonelectrosta...

Daunorubicin (or daunomycin) and Doxorubicin (or adriamycin or 14-hydroxydaunomycin) are well-known anticancer agents used in cancer chemotherapy. They are anthracycline antibiotics and are commonly used in the treatment of a wide range of cancers. Doxorubicin and Daunorubicin were chemically conjugated to PEO-b-PCL (poly(ethylene oxide)-block-poly( -caprolactone)) nanoparticles. In this resear...

A heterogeneous conductorlike solvation model (conductorlike screening model/conductorlike polarizable continuum model) that uses different local effective dielectrics for different portions of the solute cavity surface is implemented for quantum chemical Hartree-Fock and Kohn-Sham methods. A variational treatment is used to form the heterogeneous solvation operator, so a simple analytic expres...

The ability of the GROMOS96 force field to reproduce partition constants between water and two less polar solvents (cyclohexane and chloroform) for analogs of 18 of the 20 naturally occurring amino acids has been investigated. The estimations of the solvation free energies in water, in cyclohexane solution, and chloroform solution are based on thermodynamic integration free energy calculations ...

Solvation is an elementary process in nature and is of paramount importance to more sophisticated chemical, biological and biomolecular processes. The understanding of solvation is an essential prerequisite for the quantitative description and analysis of biomolecular systems. This work presents a Lagrangian formulation of our differential geometry based solvation models. The Lagrangian represe...

The P—S bond cleavage process in the hydroperoxidolysis of a model system for the nerve agent VX was studied using ab initio and semiempirical molecular orbital methods. Aqueous solvation effects were included through single-point calculations using the semiempirical SM5.2PD/A continuum solvation model and geometries optimized at the HF/MIDI! level of theory. The predominant pathway for P—S bon...

Solvation free energy is an important quantity in Computational Chemistry with a variety of applications, especially in drug discovery and design. The accurate prediction of solvation free energies of small molecules in water is still a largely unsolved problem, which is mainly due to the complex nature of the water-solute interactions. In this letter we develop a scheme for the determination o...

The solvation of fluoride and chloride anions (F(-) and Cl(-), respectively) by water has been studied using effective fragment potentials (EFPs) for the water molecules and ab initio quantum mechanics for the anions. In particular, the number of water molecules required to fully surround each anion has been investigated. Monte Carlo calculations have been used in an attempt to find the solvate...