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Reactions involving sodium bis(2ethylhexyl)sulfosuccinate (AOT) have been found to be useful as a surfactant that spontaneously aggregates into reverse micelles and water-in-oil microemulsions without the aid of a cosurfactant. Experiments in isooctane have revealed the presence of a charge transfer complex between bromine and monomeric AOT. This is in agreement with a very strong donor ability of AOT due to its sulfonate headgroup.

Solvent evaporation from hydrated peptides and model organic complexes formed by electrospray ionization was investigated using external ion source Fourier transform ion cyclotron resonance mass spectrometry. Slow evaporation of solvent from water clusters of biomolecules results in the formation of magic number clusters, clusters with increased stability. The experiments demonstrated other essential aspects of water structure around singly and multiply charged ions with low hydration levels.

A fixed-point charge potential model for water was developed. The model characterizes the vapor-liquid coexistence properties namely saturated vapor and liquid densities, vapor pressures and liquid structure of water. The Buckingham exponential-6 potential model was utilized to describe the nonpolar interactions. Critical temperature was recorded at within 0.2%, critical density at 8% and saturated liquid densities to an average of 2.5%. The model may be useful in understanding environmental remediation, biological systems and separation phenomena.

Experiments were performed to describe the cluster-surface collision dynamics. The kinetics of water cluster collisions on graphite surfaces was examined. Angular distributions for negative cluster ions were measured at surface temperatures of 1280-1450 K. The findings demonstrate sharply peaked angular distributions close to the tangential direction. During the surface interaction, the water clusters conserved 65-85% of their velocity parallel to the surface plane. The surface normal direction recorded a velocity of 75-100 m/s independent of incident angle.

A study was conducted to characterize water substitution mechanisms on the hexaaqua ions of Al3+, Ga3+ and In3+ (aluminum, gallium and indium) in aqueous solution using ab initio calculations at the Hartree-Fock level. Dissociative and associative exchange mechanisms were analyzed in seven water molecules. Findings were influenced by the model used, treatment of the second coordination and the bulk of the systems. The findings identified the mechanisms of solvent exchange at Al3+,Ga3+ and In3+ were D,D, and A.

The solvation and solvent isotope effects on the radiationless decay rates of the intersystem crossing path (ISCP) from the metal-to-ligand charge transfer (MLCT) state were evaluated through the utilization of the osmium(II) complexes. The solute-solvent interaction and hydrogen bonding of the solvent in water-dioxane and water-methanol mixtures were also studied. The solvent effect for the Os(II) complexes primarily occurred in the ISCP from the MLCT state. The rate of energy transfer was influenced by the hydration structure and the number of water molecules per Os(II) complexes.

An examination of ferric ion hydrolysis serves to test the applicability of theoretical tools that have been introduced for modeling speciation of metal ions in aqueous solution. Results are encouraging because computations of the hydrolysis reaction free energies were found to be accurate and conform to experimental thermochemistries. However, certain issues still have to be dealt with to further the description of chemical systems in molecular terms.

The modelization of the OH stretching band by three Gaussian components was found to be the most efficient decomposition and as an adequate smoothing method. This was found in an application of two independent methods to interpret the shape and the intensity of the water OH stretching vibration band in a Fourier transform infrared study of water states in Aerosol-OT (AOT) reverse micelles as a function of the water content. A Langmuir adsorption isotherm model best satisfies the criteria for a model for determining the number of water molecules bound per AOT polar head. These are their ability to fit the experimental data, to reproduce the effect of the AOT concentration, and to examine the influence of the counterion forming the ion pair with AOT.

A study is conducted on the temperature dependence of the ionic product of water, pKw. It is shown that solvation free energies help make water molecules less dissociative as temperatures increase while electronic reorganization energy promotes dissociation with increasing temperature. Temperature dependence is also determined by the characteristics of the electronic structure of OH-.

A study was conducted on a possible coupling between P680+ reduction and hydrogen transfer with emphasis on the effects of H2O/D2O exchange on the P680+ reduction kinetics in the nano- and microsecond domains. The findings indicate that at least two processes play a role in P680+ reduction by Yz. The slower processes in all or some of the S-state transitions involve proton/hydrogen motion and occur in the microsecond time domain.

The ionic exchange in a lithium chloride methanol-water solution system was measured using an equation based on the Toerell, Meyer, and Sievers theory. Permeability coefficients of the charged membranes were calculated using the charge densities and the cation-to-anion mobility ratios found in previous studies. In addition, the interaction between the ion pairs and the counterion and fixed charge groups were determined. The findings demonstrate that the regulation of ionic mobility in the sample solution was caused by the weight fraction of methanol.

A study of the number of water molecules needed to stabilize the zwitterion and shift the gas phase zwitterion-neutral equilibrium of the amino acid glycine toward the solution phase, reveals that two water molecules are sufficient to stabilize the glycine zwitterion. Two water molecules give it a minimum potential energy with at least one vibrational level. The study was made using local charge distributions.

The effects of endothelin-1 (ET-1) on water and electrolyte transport were studied in rat kidney collecting ducts (CCD). ET-1 inhibited arginine vasopressin-dependent fluid and chloride absorption, potential difference and osmotic water permeability. This demonstrates ET-1 inhibition of vasopressin-induced water and chloride reabsorption and suggests a direct function of endothelin on rat CCD.

The structures of water, partitioned in cation-exchange resin particles, were studied on the basis of fluorescence dynamics of Nile Blue A (NB). The fluorescence lifetime of NB in the resin was longer than that in water and increased with increasing cross-linking density of the resin ([Rho]). The results demonstrated that the water structures in the resin were significantly different from those in water and dependent on [Rho]. A study on solvation dynamics of NB in the resin, reflecting structured water around the ionexchange group, revealed the roles of 'bound water' molecules in the water structures, since the solvent relaxation time ([[Tau].sub.S]) in the resin was much longer than that in water and depended on [Rho]; [[Tau].sub.S] increased from 34 to 55 ps with increasing [Rho] from 2 to 8%. The origin of the [Rho] dependence of [[Tau].sub.S] was discussed in terms of the separation distance between the ion-exchange groups, and the effects of the counterion of the ion-exchange group on the solvation processes were also discussed.

It is possible to quantitatively understand all nine dipolar couplings in the proton nuclear NMR spectrum of AcAlaNHMe dissolved in a water-based liquid crystal in terms of a single dominant conformation.

A study was conducted in which the binding energies of water molecules to both divalent calcium and nickel ions were measured using blackbody infrared radiative dissociation and master equation modeling. Results showed that the hydrated calcium ion dissociated more rapidly than nickel. This was consistent with a lower hydration enthalpy due to the larger ionic radius of calcium. All hydrated ions dissociated with rate constants between 0.0015 and 0.30 s over a temperature range of 22-210 degrees Celsius.