Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Polish Journal of Chemistry

1 2004

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Analytical Functions for the Proton Transfer in the H5O+2 Complex Immersed in a Solvent (Water, 1-Octanol)

Neagoe C., Lepadatu C.

Polish Journal of Chemistry

2004

Vol. 78 / nr 2

279-285

The analytical functions for the energy barrier of the proton transfer in H5O2 + complex have been fitted by nonlinear regression from ab initio quantum mechanical calculations for the complex in gas phase and solvent phase (water, 1-octanol) simulated using the PCM approach. The best fitted function describing the proton transfer energy for any distance R between H3O+ and H2O and for any proton position is of the form E(R,r) = E(R/2)Erfc(z), where Erfc( z) is the complementary error function, z = [(r - 0.5R)/c]2, R is the O(H3O+)-O(H2O) distance, r is the space position of proton relative to R/2 and c a constant determined by regression for each proton transfer at a given R distance. The fitted functions are: E(R/2) = [a + b/(R/2)]2 which is the highest potential energy value for the proton situated at R/2 and c = a + bln(R/2). The energy barriers for the solvent phase are higher than those for the gas phase, because of the solute-solvent interactions considered by PCM. The energy barrier for the 1-octanol phase is somewhat lower than that for water phase, most likely due to the amphipathic character of the 1-octanol. The energy potential values for the proton transfer in solvent can be expressed as a sum of two terms corresponding to the gas phase and to solvent effects contributions.