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	United States Patent Application: 0040053993 (Site not responding. Last check: 2007-10-06)
		A pharmaceutical composition comprising a tocol as a solvent, and a tocol soluble ion pair comprised of a charged pharmaceutically active compound or a charged precursor of a pharmaceutically active compound, and a compound of opposite charge capable of forming a tocol-soluble ion pair with the pharmaceutically active compound or precursor.
		A composition according to claim 1 in wherein the ion pair forming compound is selected from tocol derivatives, C.sub.2-C.sub.25 fatty acids, alkyl phosphates, lipids, phospholipids, retinoids, benzoquinones and esters of Vitamin A, D and K. A composition according to claim 25 wherein the ion pair forming compound is a tocol derivative.
		Ion pairs that are not soluble in the tocol of choice readily precipitate or crystallize by these methods.
	appft1.uspto.gov /netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=/netahtml/PTO/srchnum.html&r=1&f=G&l=50&s1='20040053993' (6269 words)

	Density Functional Theory Calculations of Ion Pair Association in Aprotic Electrolytes
		We are investigating the pair interactions of lithium perchlorate in an organic solvent, ethylene carbonate (EC), and the formation of ion pairs for different solvent conditions.
		The assessment of ion pairing in these systems is important because of its effect on the ionic conductivity.
		Yet a second minimum is found in the potential energy surface in solution that may be attributed to a solvent-separated ion pair complex.
	www.nersc.gov /news/annual_reports/annrep98/balbuena.html (509 words)

	Ion pair - Wikipedia, the free encyclopedia
		In chemistry the ion pair concept (introduced by Saul Winstein) describes the interactions between a cation, anion and surrounding solvent molecules.
		In a tight or intimate or contact ion pair there are no solvents molecules between the two ions.
		The ion pair concept explains stereochemistry in solvolysis.
	en.wikipedia.org /wiki/Ion_pair (151 words)

	Ion Pair Home - Regis Technologies
		Ion Pair Chromatography is a method for improving the separation of charged analytes.
		Although the S- and Q-Series ion pair reagents can be used at wavelengths less than 210 nm, the crucial factors in determining what wavelength to use are the integrity of the detector optics and the purity of the organic modifiers.
		Ideally, the ion pair reagent concentration in the mobile phase should be 0.005 M. However, small adjustments in reagent concentration may increase retention slightly and optimize the separation [Figure 5].
	www.registech.com /ionpair (840 words)

	Patent 5116921: Superabsorbent crosslinked ampholytic ion pair copolymers
		The ampholytic ion pair monomer for use in the preparation of the present invention may be prepared by methods which are well known to those skilled in the art.
		For example, one of the ampholytic ion pair monomers can be prepared by reacting chloride salt of 2-methacryloyloxyethyltrimethylamine in the dark with the silver salt of 2-acrylamido-2-methylpropane sulfonic acid or 2-methacyloyloxyethane sulfonic acid at about 20-25 C to produce the ion-pair monomer in aqueous solution and silver chloride as a precipitate.
		Said ampholytic ion pair monomer is preferably (i) the ammonium cation 2-methacryloyloxyethyltrimethyl-ammonium; and (ii) the sulfonate anion 2-methacryloyloxyethane sulfonate; said comonomer preferably comprises acrylamide; and said crosslinking agent is methylene-bis-acrylamide which has at least two polymerizable olefinic functionalities wherein each of the olefinic functionalities is suitable for crosslinking.
	www.freepatentsonline.com /5116921.html (3365 words)

	Quantum-Chemical Study of Structure and Activity of Chain Ends in Metal-Free Anionic Polymerization of Methacrylates
		It is possible to establish a correlation based on the calculated energy difference between the ylide and the ion pair and the apparent activity of the chain end.
		Absolute energies of the ylides and ion pairs are calculated for a number of initiators, and the energy differences are correlated with the observed reactivity.
		It is shown that the isomerization of ylides to ion pairs may be rather endothermic in the initiation step, in qualitative agreement with induction periods observed during metal-free anionic MMA polymerization with phosphonium counterions.
	www.uni-bayreuth.de /departments/mcii/deutsch/publi/2003/177.htm (2639 words)

	Biophysical Journal: Relationship between ion pair geometries and electrostatic strengths in proteins
		Ion pairs play important roles in protein structure and function, such as in oligomerization, molecular recognition, domain motions, thermostability, and a-helix capping (Perutz, 1970; Fersht, 1972; Barlow and Thornton, 1983; Musafia et al., 1995; Xu et al., 1997a,b; Kombo et al., 2000; Kumar and Nussinov, 2001a,b; Kumar et al., 2000a,b, 2001 a,b).
		The electrostatic strength of an ion pair depends on the ion pair geometry and on the protein structural context.
		This facilitates the study of the relationship between geometry and electrostatic strength of the ion pair because the effect due to the variations in the protein structural context on its electrostatic strength is minimized, though not completely removed.
	www.findarticles.com /p/articles/mi_qa3938/is_200209/ai_n9112847 (1314 words)

	ion pair -- Encyclopædia Britannica
		An ion pair, for the physicist, is the positively charged particle (positive ion) and the negatively charged particle (negative ion) simultaneously produced by the addition of sufficient energy to a neutral atom or molecule to cause it to…
		An ion pair, for the physicist, is the positively charged particle...
		An ion chamber is a device in which two electrodes are arranged on opposite sides of a gas-filled volume.
	www.britannica.com /eb/article?tocId=9042692 (581 words)

	Relationship between Ion Pair Geometries and Electrostatic Strengths in Proteins -- Kumar and Nussinov 83 (3): 1595 -- ...
		The ion pairs and NMR conformer ensembles used in the present study are shown in Table 1.
		is that of ion pair E151-R176 in the NMR conformer ensemble (
		Fluctuations between stabilizing and destabilizing electrostatic contributions of ion pairs in conformers of the c-Myc-Max leucine zipper.
	www.biophysj.org /cgi/content/full/83/3/1595 (5771 words)

	The Lewis Definitions of Acids and Bases (Site not responding. Last check: 2007-10-06)
		The electron configuration of the Al ion suggests that this ion has empty 3 s, 3 p, and 3 d orbitals that can be used to hold pairs of nonbonding electrons donated by neighboring water molecules.
		ion is formed when an Al ion acting as a Lewis acid picks up six pairs of electrons from neighboring water molecules acting as Lewis bases to give an acid-base complex, or complex ion.
		ion has been transferred from one of these oxygen atoms to the other, all of the oxygen atoms in the compound are electrically neutral.
	chemed.chem.purdue.edu /genchem/topicreview/bp/ch11/lewis.html (664 words)

	Ion Pair Products - Regis Technologies
		Ion pair concentrates -- premixed 0.5 M solutions of alkyl sulfonates.
		Ion pair concentrates -- premixed 0.5 M solutions of alkyl amines.
		Other bulk Ion Pair reagents such as Tetrabutylammonium phosphate, Trihexylamine and Triheptylamine are complementary reagents used for the resolution of negatively charged analytes.
	www.registech.com /ionpair/ionpairprod.html (322 words)

	Contribution of ion pair complexation with bile salts to biliary excretion of organic cations in rats -- Song et al. ...
		Contribution of ion pair complexation with bile salts to biliary excretion of organic cations in rats -- Song et al.
		Contribution of ion pair complexation with bile salts to biliary excretion of organic cations in rats
		The objective of this study was to examine whether ion pair complexation with endogenous bile salts in hepatocytes contributes
	ajpgi.physiology.org /cgi/content/abstract/281/2/G515 (236 words)

	MSN Encarta - Search Results - ion pair
		MSN Encarta - Search Results - ion pair
		Ion (chemistry), particle formed when a neutral atom or group of atoms gains or loses one or more electrons.
		Search Amazon.com for books about your topic, "ion pair"
	encarta.msn.com /ion+pair.html (192 words)

	Contribution of ion pair complexation with bile salts to biliary excretion of organic cations in rats -- Song et al. ...
		ion pair complexes is necessary for the complexes to be transported
		The concentration of the ion pair complex was approximated as described in
		in the uptake of the ion pair complexes was proposed.
	ajpgi.physiology.org /cgi/content/full/281/2/G515 (6803 words)

	Mattson, Stephanie Margaret (1985-01-11) Optical expressions of ion-pair interactions in minerals. ...
		The optical characteristics of Fe3+ in red Fe3+ rich and fl Fe3+,Fe2+-rich tourmalines were examined by absorption spectroscopy in the visible and near-infrared, Mossbauer spectroscopy and magnetic susceptibility measurements.
		The variation of molar absorptivity of Fe2+ bands with the fraction of Fe2+ in Fe2+-Fe3+ pairs indicates that Fe3+ ions increase the absorptivity of Fe2+ bands to ~1200 [...] as compared to ~5 [...] for non-interacting Fe2+.
		Although the detailed behavior of non-interacting Fe2+ ions differ in Mg-tourmalines and Li,Al-tourmalines, the characteristics of Fe2+-Fe3+ absorption are constant.
	resolver.caltech.edu /CaltechETD:etd-04082005-133814 (913 words)

	Relationship between Ion Pair Geometries and Electrostatic Strengths in Proteins -- Kumar and Nussinov 83 (3): 1595 -- ...
		The electrostatic free energy contribution of an ion pair in a protein depends on two factors, geometrical orientation of
		structural context of the ion pair in the protein.
		ion pairs in 14 NMR conformer ensembles for 11 nonhomologous proteins.
	www.biophysj.org /cgi/content/abstract/83/3/1595 (459 words)

	.: Research - Richard Research Group :.
		By comparison, the rate constants for reversible separation of ion pairs to free ions show a much smaller dependence on the structure of the ions and a significant dependence on the solvent.
		Our work has focused on the detection and analysis of "signature" of ion pair reactions with the specific goal of determining absolute rate constants for these processes.
		This is a challenging problem given the ephemeral nature of ion pairs in water and their short short lifetimes of ca.
	www.acsu.buffalo.edu /~jrichard/r_ionpairs.html (550 words)

	[No title] (Site not responding. Last check: 2007-10-06)
		Ion pairing and dissociation at liquid/liquid interfaces: Molecular dynamics and continuum models
		In particular, the equilibrium free energy calculations show that the ion-pair is locally stable at the interface and that the dissociation must involve ion transfer and considerable change in the interface structure.
		These are also confirmed by the non-equilibrium dynamics calculations: Dissociation of the ion pair at the interface involves a simultaneous transfer of both ions into the aqueous side of the interface.
	www.chemistry.ucsc.edu /~benjamin/research/abs74.html (194 words)

	Exciplex and ion pair quenching in a chiral hexahelicene-amine system
		Exciplex and ion pair quenching in a chiral hexahelicene-amine system.
		in the range 10-24) and ion pair quenching is found in highly polar solvents (acetonitrile,.epsilon.
		Exciplex and ion pair quenching are parallel pathways in the quenching of the fluorescence of HH· as demonstrated in methanol soln.
	www.uni-hohenheim.de /i3ve/00068900/19406041.htm (127 words)

	Ion Pair Transition Scheme (Site not responding. Last check: 2007-10-06)
		The A valence state of ClO enables transitions from the ground state to the ion pair states by two photons.
		The diagram shows the expected positions of the ion pair states by plotting the Coulombic attraction between two ions as the outer well of the potential energy curves, and estimating the inside of the well with the sum of the relevant ionic radii.
		Above this energy the A state is no longer available to allow transitions to the ion pair states.
	www.chm.bris.ac.uk /pt/western/clo/ionpair.htm (205 words)

	I
		An ion pair, the constituent ions of which are in direct contact (and not separated by an intervening solvent or other neutral molecule) is designated as a "tight ion pair" (or "intimate" or "contact ion pair").
		In "solvent-shared ion pairs" the ionic constituents of the pair are separated by only a single solvent molecule, whereas in "solvent-separated ion pairs" more than one solvent molecule intervenes.
		However, the term "solvent-separated ion pair" must be used and interpreted with care since it has also widely been used as a less specific term for "loose" ion pair.
	www.chem.qmw.ac.uk /iupac/gtpoc/I.html (3520 words)

	Patent 4472286: Perfluoroalkyl anion/perfluoroalkyl cation ion pair complexes
		It was also found that the instant R.sub.f R.sub.f ion pair complexes do impart oil and water repellency to substrates such as textiles, fibers, nonwovens and paper.
		Similarly it is shown in Table 3, that the R.sub.f R.sub.f ion pair complexes are superior surface tension depressants as compared with the precursor anionic and cationic surfactants.
		The R.sub.f -cationic/R.sub.f -anionic ion pair complexes demonstrate oil repellency when applied as a paper size or as a textile finish.
	www.freepatentsonline.com /4472286.html (6801 words)

	Ion pair stability in bacteriorhodopsin (Site not responding. Last check: 2007-10-06)
		Comparison of the PA of the retinal Schiff base and a model for the aspartate side chain shows that the ion pair cannot be found stable within gas phase calculations.
		The explicit inclusion of the protein environment, however, seems to be essential for obtaining a stable ion pair.
		Without inclusion of further stabilization effects, for example explicit consideration of the monopole/dipole effects of the environment and/or inclusion of implicit solvent models, one cannot approach any stable ion pair of the protonated Schiff base group and negatively charged aspartate, which is believed to exist in bacteriorhodopsin as the starting configuration before the photocycle.
	genome.dkfz-heidelberg.de /users/emad/pub_abs/cosmo_abs.html (435 words)

	Regis Technologies, Inc is a manufacturer and supplier of chromatography products including high performance liquid ...
		Regis Technologies, Inc is a manufacturer and supplier of chromatography products including high performance liquid chromatography (HPLC) columns for specialty separations and conventional use, ultrapure derivatization reagents for GC and HPLC, ion pair reagents and buffers for HPLC.
		Ion Pair Reagents/Buffers: Regis Technologies, Inc manufactures ultrapure Ion Pair reagents and buffers on-site.
		Both anionic and cationic ion pairing reagents in pentyl, hexyl, heptyl, octyl, and dodecyl chain lengths.
	www.zhdanov.ru /classified-catalogue/r-companies/regis_technologies.htm (546 words)

	Effect of Analogue Ions in Normal-Phase Ion-Pair Chromatography of Quaternary Ammonium Compounds (Site not responding. Last check: 2007-10-06)
		Louis H. Bluhm and Tingyu Li The effect of analogue ions of ion-pair reagents in the normal-phase ion-pair chromatographic behavior of quaternary ammonium compounds is shown.
		Among the ion-pair reagents investigated (sodium bromide, tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide, and tetrabutylammonium bromide), tetramethylammonium bromide proves to be the most effective reagent for both reducing retention time and eliminating peak tailing.
		The influence of analogue ions on the chromatographic behavior of quaternary ammonium compounds correlates well with their affinity for normal-phase silica gel.
	www.j-chrom-sci.com /abstracts/1999/august/273-li.htm (157 words)

	Contributions of an Interdomain Ion Pair to the Bifunctional Properties of Catalase-Peroxidases (Site not responding. Last check: 2007-10-06)
		Contributions of an Interdomain Ion Pair to the Bifunctional Properties of Catalase-Peroxidases
		We have observed a series of strictly conserved interactions at the interdomain interface that may account for the role of the C-terminal domain in catalase-peroxidase function.
		Interestingly, the catalase activity of Arg117Ala was highly dependent upon the timing of heme availability, suggesting the possibility that the Arg117-Asp597 ion pair supports the formation of an intrasubunit covalent adduct essential for catalase but not peroxidase activity.
	acs.confex.com /acs/56serm/techprogram/P13249.HTM (267 words)

	IIB Spring 96 Paper No. 6 (Site not responding. Last check: 2007-10-06)
		A new method is presented for deriving the Fano factor and the mean energy per ion pair in the ultrasoft x-ray energy range.
		It is based on counting electrons deposited by a photon in a low-pressure gas, and is applicable for all counting gases.
		The energy dependence of these parameters for several hydrocarbons and gas mixtures is presented.
	www.slac.stanford.edu /pubs/icfa/spring96/paper6a.html (76 words)

	Ion pair states of the ClO Radical (Site not responding. Last check: 2007-10-06)
		Ion Pair States of the ClO Radical Observed by Multiphoton Ionisation Spectroscopy
		Gaithersburg, Maryland 20899, U.S.A. We report isotopically selected, multiphoton ionisation spectra of the ClO radical following excitation in the wavelength range 276-261 nm, obtained using both a room temperature sample and under the rotationally cold conditions prevailing in a pulsed molecular beam.
		These we deduce to possess very extended equilibrium bond lengths ( R ~ 2.4 Å), and thus associate with one or more ion pair states.
	www.nist.gov /kinetics/hudgens/abstracts/clo_abs1.html (236 words)

	Session OWP2 - Poster Session: Displays, Lamps, and Lasers.
		Time-dependent fluid equations (continuity equations) are used to describe the movement of the ions.
		Apart of a vague statement about an extended continuum, peaking at 237 nm, and a tentative assignment for a dozen of ion pair states, little is known about their complex structure.
		Kinetic simulation yields the ion energy distribution which plays an important role in secondary electron emission and MgO sputtering but it is not efficient computationally.
	flux.aps.org /meetings/YR98/BAPSGEC98/abs/S4400.html (2860 words)

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