Free energy of a charge distribution in a spheroidal cavity in a polarizable dielectric continuum

Harrison, S. W.; Nolte, H.J.; Beveridge, David L.

doi:10.1021/j100564a010

Cited by 28 publications

(8 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…points 19-23, will be discussed at the end of this section.) The static dielectric constant of medium for most of these points is virtually the same (in the range of [37][38][39][40][41][42][43][44][45], and they fit the other straight line. The four points that drop out from the line, i.e., propylene carbonate (6), acetone (3), dichloroethane (12), and dichloromethane (13), have a considerably different st of 65, 21, 10, and 9, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…The solution of the electrostatic problem for a set of spherical charges inside the cavity coincides with that for the corresponding set of point charges . The analytical solution of the electrostatic problem for a set of point charges inside oblate spheroid cavity was taken from ref . In evaluating the integrals in eq 13, we used point charge approximation of spherical charges: the integrals were replaced by the products of the potentials at the center of each spherical charge and its total value.…”

Section: Calculations Of the Solvent Reorganization Energymentioning

confidence: 99%

See 1 more Smart Citation

Stokes Shift as a Tool for Probing the Solvent Reorganization Energy

1997

View full text Add to dashboard Cite

The difference between the maxima of absorption and fluorescence spectra, the Stokes shift, is affected by dynamic properties of the solvent, namely by the solvent reorganization free energy, E s . Stokes shift a dye, proflavine, in polar aprotic solvents and in alcohols is examined. We report that the experimentally observed dependence of E s on the solvent dielectric properties can be explained only when two effects are taken into account. The first effect is the distortion of dielectric properties of a uniform solvent by embedding a bulk solute molecule in the solvent. The second effect is the influence of the solvent polarity on the electronic density redistribution upon the electronic transition. Our model evaluations of E s are based on quantum chemical calculations of solvent effects on charge redistribution of the dye upon excitation and on subsequent calculations of E s in the framework of a model of a cavity in a continuum dielectric. We show that the continuum approach is able in the present case to provide a reasonable correlation between E s and the dielectric properties of the solvent. An experimentally observed 15%-30% difference in the values of E s for polar aprotic solvents and for alcohols cannot be explained in terms of the continuum approach. Our data show that commonly adopted equation for Stokes shift that establishes equality between Stokes shift and the doubled reorganization energy is generally not rigorous. The experimental data obtained are consistent with a more rigorous approximation of Stokes shift that takes into account the quantum nature of the solute local modes.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Calculations Of the Solvent Reorganization Energymentioning

confidence: 99%

Stokes Shift as a Tool for Probing the Solvent Reorganization Energy

1997

View full text Add to dashboard Cite

show abstract

“…25,26,41 However, in general, a realistic charge distribution of a neutral or ionic molecular system in the cavity, even if the cavity is approximated to be spherical, can be simply described by neither monopole nor point dipole. The multipole expansion approach, 5,42,43 in such cases, should be adopted.…”

Section: Multipole Expansion Of Polarization Potentialmentioning

confidence: 99%

Continuous medium theory for nonequilibrium solvation: III. Solvation shift by monopole approximation and multipole expansion in spherical cavity

Zhu

et al. 2005

J Comput Chem

View full text Add to dashboard Cite

According to the classical electrodynamics, a new and reasonable method about electrostatic energy decomposition of the solute-solvent system has been proposed in this work by introducing the concept of spring energy. This decomposition in equilibrium solvation gives the clear comprehension for different parts of total electrostatic free energy. Logically extending this cognition to nonequilibrium leads to the new formula of electrostatic free energy of nonequilibrium state. Furthermore, the general solvation shift for light absorption/emission has been reformulated and applied to the ideal sphere case with the monopole approximation and multipole expansion. Solvation shifts in vertical ionizations of atomic ions of some series of main group elements have been investigated with monopole approximation, and the variation tendency of the solvation shift versus atomic number has been discussed. Moreover, the solvation shift in photoionization of nitrate anion in glycol has been investigated by the multipole expansion method.

show abstract

“…The solvophobic potential (C@) is a free-energy term, unlike U , yet it has been shown [2,3] that it can be added to U and used as if it were an ordinary potential, in the partition function (PF) to get the equilibrium thermodynamic quantities Basically C @ has three terms in it [ 11: (i) the free-energy G, of creating the cavity surface area in the solvent enveloping our molecule, A; (ii) the free energy of interaction Cint of all pieces of A with the cavity wall solvation layers around and the liquid beyond, and (iii) the reduction of the in oacuo interactions between the pieces (atoms, molecular groups) of A due to the presence of solvent around, Gkd (van der Waals parts [4], induction parts, electrostatic parts [5,6], reduced separately. )…”

Section: The Solvophobic Potentialmentioning

confidence: 99%

The solvophobic theory for the prediction of molecular conformations and biopolymer bindings in solutions with recent direct experimental tests

Si̇nanoğlu

1980

Int J of Quantum Chemistry

View full text Add to dashboard Cite

Molecules exposing considerable microsurface areas to the surrounding solvent such as amino acids, nucleotide bases in biopolymers, or various drug molecules, antigens, and substrates, tend to be pulled apart or pushed together as the case may be by the surrounding solvent medium. These solvophobic forces and their quantitative theory were introduced sometime earlier [ O . Sinanoglu, in Molecular Associations in Biology, B. Pullman, Ed. (Academic, New York, 1968), pp. 427-445; and references therein]. The forces involve both enthalpy and entropy effects. The case in water had been shown to involve particularly strong forces but not differing in kind from other solvents. There are still somewhat contradictory views on the aqueous case, referred to in the literature as "hydrophobic bonding," treated as a phenomena unique to water and previously thought to involve only entropic effects. The temperature dependence and volumetric effects on the earlier type of "hydrophobic bonding" are presently not always reconcilable with recent experimental evidence. By contrast, the solvophobic force theory allows the calculation of the full solvent effect on various association or isomerization equilibria using its quite rigorous relations and basic data derived with it from liquids and solutions. [cf., e.g., for an early application to cis-trans azobenzene isomerization, T. HalEioglu and 0. Sinanoglu, Ann. N.Y. Acad. Sci., 158, 308 (1969)j. The solvophobic force theory had also introduced as a measurable new quantity, "the thermodynamic microsurface area change of a reaction," which is now finding considerable use in protein chemistry [cf., e.g., F. M. (CIBA, New York, 1977)l. Solvophobic force theory has been tested and applied recently in detail in high pressure liquid chromatography (HPLC) by C. HorvAth, W. Melander, and I. Molnar [J. Chromatograph. 125, 123 (1976)] who verified the predicted temperature, molecular surface area, and salt concentration dependence. It worked well when applied in detail to the complicated methanol-water mixtures as well. The theory also gave the first a priori derivation of the experimentally well-known protein salting-in~salting-out curve [W. Melander and C. Horvath, Arch. Biochem. Biophys. 183, 200 (1977)j. We have now extended the theory further with new basic derivations which eliminate the need for the direct calculation of some cumbersome effects. The theory has also been recently applied to a number of new areas including drug-receptor interactions, aqueous amino acid interactions, and to multicomponent phase equilibria; the latter also of chemical engineering interest. Solvophobic interactions, although part statistical-thermodynamical in nature, were shown to be usable as if they were an ordinary U ( R ) potential added on to quantum-chemical intrinsic in uacuo potentials for prediction of conformations in solution [O. Sinanoilu, in The World ofQuantum Chemistry, R. Daudel and B. Pullman, Eds. (Reidel, Dordrecht. 1974)]. There have also been some recent applications that illustr...

show abstract

Free energy of a charge distribution in a spheroidal cavity in a polarizable dielectric continuum

Cited by 28 publications

References 1 publication

Stokes Shift as a Tool for Probing the Solvent Reorganization Energy

Stokes Shift as a Tool for Probing the Solvent Reorganization Energy

Continuous medium theory for nonequilibrium solvation: III. Solvation shift by monopole approximation and multipole expansion in spherical cavity

The solvophobic theory for the prediction of molecular conformations and biopolymer bindings in solutions with recent direct experimental tests

Contact Info

Product

Resources

About