Results 251 to 260 of about 110,863 (301)

An ionomer with a fluorescence sensitivity to the nature of the counterion and the degree of ion-pair association

Macromolecules, 1993
Butyl methacrylate copolymers with 3-(methacryloylamino)-2-naphthoic acid (MANA) carrying alkali counterions exhibit in highly dilute dioxane or toluene solution two emission bands, one (a) with a maximum at 405-415 nm, the other (β) with a maximum at 490-500 nm.
Frantisek Mikes, Herbert Morawetz, Drahomir Vyprachticky   +2 more
openaire   +1 more source

Ion Pair Association Constants and Solvent Composition

Nature, 1967
THE variation of ion-pair association constants, KA, with change in solvent is generally summarized as a plot of log KA against the reciprocal of the solvent permittivity, e, thereby testing the success of theoretical treatments of ion association1. Generally, agreement between theory and experiment is qualitative rather than quantitative. For example2,
openaire   +1 more source

Associative and Non‐Associative Ion Pair Formation by Fast Atoms

Berichte der Bunsengesellschaft für physikalische Chemie, 1973
AbstractThis review discusses recent results on collision processes of accelerated atoms which lead to ion production. Five general classes of reactions are described ‐ collision‐induced dissociative ion pair formation (polar dissociation), electron transfer, associative ionization, reactive (rearrangement) ionization, and simple collisional ionization.
openaire   +1 more source

Photoinduced electron transfer in the ion pair compound (XTOn): influence of ionic association

Journal of Photochemistry and Photobiology A: Chemistry, 1996
Abstract The influence of the ionic dissociation equilibrium on the photochemical and photophysical properties of xanthene dye onium salts (XTOn) was studied. The dissociation constants (KD) determined by conductivity verify that the ionic association states directly influence the changes in the absorption spectral shape, and the ratio I532/I445 ...
Wenhui Zhou, Erjian Wang
openaire   +1 more source

[Association and isochromatization of ion-pair of the acid and basic].

Guang pu xue yu guang pu fen xi = Guang pu, 2010
In this paper, the method for forming the isochromatic dye ion-pair was described, and the mechanism and the types of the association of the ion-pair studied. The isochromatization of the associated reaction and the solvent effect were discussed by the electron theory with the absorption spectrum and energy diagram.
L, Ding, X, Zhao
openaire   +1 more source

Thermodynamics of Na+ Cl− ion – pair association in acetonitrile–dimethyl sulfoxide mixtures

Chemical Physics Letters, 2015
Abstract Molecular dynamics simulations of Na+ Cl− ion pairs in acetonitrile–dimethyl sulfoxide mixtures have been performed as a function of salt concentration and the composition of mixtures. Temperature dependence of the potentials of mean force (PMFs) is studied to assess the enthalpy and entropy contributions to the PMFs.
PATIL, UN, KESHRI, S, TEMBE, BL
openaire   +2 more sources

Free energies of association for the sodium-dimethyl phosphate ion pair in aqueous solution

The Journal of Physical Chemistry, 1989
Utilisation de la theorie de perturbation mecanique statistique et d'une simulation par ordinateur de la dynamique moleculaire pour obtenir les potentiels de force moyenne du systeme sodium-dimethylphsphate.
Shawn E. Huston, Peter J. Rossky
openaire   +1 more source

Dispersion and polarization forces associated with the ion-pair states of diatomic molecules

Chemical Physics, 1988
Abstract Heteronuclear ion-pair states have large dipole moments that are absent in the corresponding homonuclear states. It is shown that the large intermolecular polarization forces that arise in the heteronuclear case are precisely matched by anomalously large dispersion forces in the homonuclear case that come from a giant g ↔ u electronic ...
openaire   +1 more source

Effects of ion pair association on the barrier to hindered internal rotation in nitrobenzophenone and dinitrobenzophenone radical anions

The Journal of Physical Chemistry, 1983
Radical anions formed by benzophenone (BF), 4,4′-dinitrobenzophenone (DNBF), and 4-nitrobenzophenone (NBF) and ion pairs formed by these compounds with alkali metals show hindered rotation of the two rings on the ESR time scale in the temperature range explored. Activation parameters for the rotation have been obtained.
M. Barzaghi, S. Miertus, C.Oliva, E.Ortoleva, M. Simonetta   +4 more
openaire   +2 more sources

Statistical Mechanics of Ion-Pair Association in Ionomers

1987
When ion-pairs in bulk ionomer or its solutions associate to form clusters there is a change in the free energy of the system. Cluster formation must, of course, lead to a minimum in the free energy at the equilibrium state. One can think of the free energy change with cluster formation as consisting of three additive components: an energy of cluster ...
openaire   +1 more source