Results 261 to 270 of about 561,896 (299)

Rare gas–iodine complexes in the ion-pair states

Chemical Physics, 2005
Abstract Luminescence and luminescence excitation spectra in the vicinity of the optical–optical double resonance transitions to the I 2 ( f 0 g + , v f  = 8 and 9, J f  ≈ 55) levels have been measured at the bulb conditions for the I 2  + Rg mixtures (Rg = He, Ar, Xe) at the rare gas pressures 2–20 Torr and room temperature ...
M.E. Akopyan, I.Yu. Novikova, S.A. Poretsky, A.M. Pravilov   +3 more
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Ion-pair complexes of methyl viologen and anionic solutes

Chemical Physics Letters, 1984
Methyl viologen forms ion-pair complexes with anionic solutes such as EDTA, hexametaphosphate, acetate, citrate and sulfide ions. The luminescence properties of all complexes are similar, exhibiting an emission maximum centered about 520 nm and an excitation peak at 405 nm. The lifetime of the luminescence is on the order of 5 ns.
J.P. Kuczynski, B.H. Milosavljevic, A.G. Lappin, J.K. Thomas   +3 more
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Calix[n]pyrroles as Anion and Ion-Pair Complexants

2010
Abstract This chapter covers advances in calixpyrrole chemistry and specifically in the application of these species as anion and ion-pair complexation agents over the last 5 years. Over this time, the chemistry of these easy-to-make macrocycles advanced with the discovery of the ion-pair complexation properties of calixpyrroles, in addition to the ...
Gale, Philip A., Lee, Chang-Hee
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Insertion complexes of an organic molecule trapped in ion-pairs

New Journal of Chemistry, 2010
A group of novel molecule-insertion complexes M–C3H6–X (M–X = alkali-halide, -oxide, -hydroxide) is introduced and studied ab initio. Charge distributions indicate essentially neutral molecule trapped between opposite ions significantly bending and polarizing it. The system stabilities for different dissociation channels, and structure perturbations by
Gurpaul Kochhar, Fedor Y. Naumkin
openaire   +1 more source

Hydrogen-bonded and ion-pair complexes in aprotic solvents

Faraday Symposia of the Chemical Society, 1975
The proton-transfer reactions between acids and bases in aprotic solvents of low relative permitivity lead to the production of ion-pair complexes via hydrogen-bonded reaction intermediates. For most systems the rate-limiting step is the formation of the hydrogen-bonded intermediate.
J. E. Crooks, B. H. Robinson
openaire   +1 more source

Ion Pairing and Host−Guest Complexation in Low Dielectric Constant Solvents

Journal of the American Chemical Society, 2003
We report an equilibrium treatment for complexation of ionic species in low dielectric constant media that explicitly includes ion pairing of one of the components. Experimental validation was achieved through study of pseudorotaxane formation between dibenzylammonium salts and dibenzo-24-crown-8.
Jason W, Jones, Harry W, Gibson
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Formation of a ternary complex between chitosan and ion pairs of strontium carbonate

International Journal of Biological Macromolecules, 1998
This work deals essentially with the study of the interactions between chitosan and an alkaline-earth metal: 85Sr. We showed that addition of carbonate ions is necessary to observe this interaction, but only for pH values over 11. The use of an appropriate calculation software allowed us to determine the nature of the strontium ionic species present in
E, Piron, A, Domard
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Cooperativity and Complexity in the Binding of Anions and Cations to a Tetratopic Ion-Pair Host

Journal of the American Chemical Society, 2014
Cooperative interactions play a very important role in both natural and synthetic supramolecular systems. We report here on the cooperative binding properties of a tetratopic ion-pair host 1. This host combines two isophthalamide anion recognition sites with two unusual "half-crown/two carbonyl" cation recognition sites as revealed by the combination ...
Ethan N W, Howe, Mohan, Bhadbhade, Pall, Thordarson   +2 more
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Ion pairs and complexes: Free energies, enthalpies, and entropies

Journal of Chemical Education, 1969
It is the purpose of this paper to clarify the relationship of equations relating stability constants to parameters such as the size of ions and the dielectric constant of solvents to one another a...
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Organic-Soluble Enzyme Nano-Complexes Formed by Ion-Pairing with Surfactants

2011
The solubilization of enzymes in organic solvents for non-aqueous biocatalysis has attracted considerable attention since the homogeneous distribution accounts for a drastically improved reaction efficiency compared to enzymes dispersed as aggregates in an organic phase.
Songtao, Wu, Andreas, Buthe, Ping, Wang
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