ISSN:
1573-9171
Keywords:
ionogen
;
contact ion pair
;
noncontact ion pair
;
solubility
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Characteristics of the ion pairs HCOO−·Na+·H2O, HCOO−·K+·H2O, and also Na+·H2O and K+·H2O were calculated by the nonempirical Hartree—Fock—Roothan linear-combination-of-atomic-orbitals self-consistent-field (SCF) molecular-orbital method in a two-exponent Dunning basis using an extended set of Huzinaga—Dunning Gaussian functions. The basis was supplemented by polarization functions ofd type for the oxygen atom andp type for the H atom and also by diffusion functions ofp type for the oxygen atom. Characteristics of the ion pairs HCOO−·Li+ and HCOO−·Na+ were calculated taking into account the electronic correlation according to the Möller — Plesset second-order perturbation theory. Significant quantitative difference was observed in the hydration of ionogens and free cations. The stability of the ionogens HCOOMe in aqueous solutions, increasing from Li+ to Cs+, is not explained by the difference between the energies of complexation and the energies of hydration of the cations. The better solubility of the salt molecule with a cation of smaller radius is due to the higher degree of hydration of that ionogen.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01150734
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