Search results for " metal ions"

showing 4 items of 24 documents

Coamplexation of mercury(II) compounds by crown ethers in organic media

1991

Complexes between crown ethers having ring sizes of 15–24 atoms and 5 to 8 oxygens with HgX2 species (X = Cl, I, CN, SCN) have been prepared and studied. Interactions of the substituents X bound to mercury with groups or fragments in the crown compound are essential in determining the characteristics and stability of the complexes formed. Complexes with crowns of 18C6 ring sizes are the most favourable except for HgX2 compounds for which the size of X is larger than the macrocycle ring, as is the case for X = CF3.

chemistry.chemical_classificationInorganic chemistrychemistry.chemical_elementGeneral ChemistryCondensed Matter PhysicsOrganic mediaTransition metal ionsMercury (element)chemistry.chemical_compoundchemistryDivalent metal ionsPolymer chemistryCrown etherFood ScienceCyclophaneJournal of Inclusion Phenomena and Molecular Recognition in Chemistry
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Transition metal ion induced hydrogelation by amino-terpyridine ligands

2014

Hydrogelation behavior of a new class of terpyridine based metallogelators are explored. The gelation and the gel morphology was found to be critically dependent on divalent metal ions, anions and on subtle structural changes on the gelator molecule.

chemistry.chemical_compoundchemistryLigandDivalent metal ionsOrganic ChemistryInorganic chemistryPolymer chemistryPhysical and Theoretical ChemistryTerpyridineBiochemistryta116Transition metal ionsOrganic and Biomolecular Chemistry
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Enhancement of Hydrolysis through the Formation of Mixed Heterometal Species: Al3+/CH3Sn3+ Mixtures

2013

ABSTRACT: The hydrolysis of mixed-metal cations (Al3+/CH3Sn3+) was studied in aqueous solutions of NaNO3, at I = 1.00 ± 0.05 mol·dm−3 and T = 298.15 K, by potentiometric technique. Several hydrolytic mixed species are formed in this mixed system, namely, Alp(CH3Sn)q(OH)r with (p, q, r) = (1, 1, 4), (1, 1, 5), (1, 1, 6), (2, 1, 4), (1, 2, 5), (1, 4, 11), (1, 3, 8), and (7, 6, 32). The stability of these species, expressed by the equilibrium: pAl3+ + qCH3Sn3+ + rOH− = Alp(CH3Sn)q(OH)r 3(p+q)−r, βpqr OH, can be modeled by the empirical relationship: log βpqr OH = −3.34 + 2.67p + 9.23(q + r). By using the equilibrium constant Xpqr relative to the formation reaction: pAl(p+q)(OH)r + q(CH3Sn)(p+q…

equilibrium analysiequilibrium analysis; mixed hydrolysis of metal ions; aluminium(III); monomethyltin(IV)monomethyltin(IV)Aqueous solutionChemistryStereochemistryGeneral Chemical EngineeringPotentiometric titrationEmpirical relationships Formation reaction Mixed species Mixed systems Potentiometric techniqueGeneral ChemistryPotentiometric techniqueMedicinal chemistryTurn (biochemistry)HydrolysisMixed systemsMixed speciesMixed systemsMixed speciesEmpirical relationshipsSettore CHIM/01 - Chimica AnaliticaSolubilityaluminium(III)mixed hydrolysis of metal ionFormation reactionEquilibrium constantJournal of Chemical & Engineering Data
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Recognition of alkali metal halide contact ion pairs by uranyl-salophen receptors bearing aromatic sidearms. The role of cation-pi interactions.

2005

Hard anions have long been known to bind strongly to the uranium of uranyl-salophen complexes. Upon functionalization of the salophen framework with one or two benzyloxy substituents, efficient ditopic receptors for alkali metal ions are obtained. The solid-state structures of complexes formed by the two-armed receptor 1 with CsF and with the chlorides of K+, Rb+, and Cs+ reported here reveal the existence of dimeric supramolecular assemblies in which two receptor units assemble into capsules fully enclosing (MX)2 ion quartets. In addition to the strong coordinative binding of the anion to the uranyl center and to electrostatic cation-anion interactions, stabilizing interactions arise from …

host-guest recognitionStereochemistrySupramolecular chemistryGeneral ChemistryCrystal structureAlkali metalUranylBiochemistrysupramolecular chemistryCatalysisIonchemistry.chemical_compoundCrystallographyalkaly metal ions. ditopic receptorsColloid and Surface ChemistrychemistryAlkali metal halideX-ray crystallographyReceptorJournal of the American Chemical Society
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