Aquation

About: Aquation is a research topic. Over the lifetime, 1443 publications have been published within this topic receiving 17507 citations.

Photochemistry of iodopentaamminerhodium(III) in zeolite Y

Abstract: Etude de la photochimie des complexes de metaux de transition sur zeolites par la photoaquation du complexe de Rh III sur zeolite Y completement ou partiellement hydratee. Spectres IR de l'ion NH 4 + . Par irradiation a 436 nm, rendements quantiques: 0,18±0,03 (zeolite hydratee) et 0,13±0,03 (zeolite partiellement deshydratee)

Chromium(III)-isocinchomeronato and quinolinato complexes: kinetic studies in NaOH solutions and effect on 3T3 fibroblast proliferation

Abstract: The aquation of chromium(III)-isocinchomeronato and quinolinato complexes, mer-[Cr(icaH)3]0 and mer-[Cr(quinH)3]0 (where icaH− and quinH− are N,O-bonded isocinchomeronic and quinolinic acid anion, respectively) was studied in NaOH solutions. The process leads to successive ligand liberation in the fully deprotonated species. The kinetics of the first ligand liberation were studied spectrophotometrically in the visible region. A mechanism is proposed in which the rate of the chelate-ring opening at the Cr–N bond is much faster than the rate of the Cr–O bond breaking. The rate-determining step is described by the rate law: k obs1 = k OH(1) + k O Q 2 [OH−], where k OH(1) and k O are rate constants of the first ligand liberation from the hydroxo- and oxo-forms of the intermediate, respectively, and Q 2 is an equilibrium constant between these two protolytic forms. The first pseudo-first-order rate constants (k obs1) were calculated using SPECFIT software for an A → B → C reaction pattern. The results are compared with those determined in acidic medium. Kinetics of the second and third ligand liberation were also studied and values of successive pseudo-first-order rate constants (k obs2, k obs3) are [OH−] independent. Effect of chromium(III)-quinolinato and isocinchomeronato complexes on 3T3 fibroblast proliferation was evaluated. Cytotoxicity of these complexes is low, suggesting they may be promising candidates as novel dietary supplements.

Photophysical and photochemical properties of cobalt(III) phosphite complexes

Abstract: Etude de l'emission a partir de l'etat 3 T 1g de [Co(P) 6 ](ClO 4 ) 3 avec P=P(OCH 2 ) 3 CCH 3 et a partir de [Co(pom-pom) 3 ](ClO 4 ) 3 avec pom-pom=(CH 3 O) 2 PCH 2 CH 2 P(OCH 3 ) 2 . Photolyse de Co(pom-pom) 3 3+ conduisant a une photoaquation. Etude cinetique

Kinetics and Mechanism of Aquation and Anation of Some Amino Acid Pentamminecobalt(III) Complexes in Acid Aqueous Solutions

Abstract: Kinetics of aquation has been studied with pentamminecobalt(III) complexes containing aliphatic amino acids (γ-aminobutyric acid, e-aminocaproic acid, α-amino-isobutyric acid, ornithine, and proline), aromatic acids (benzoate, anthranilic, and p-aminobenzoic acid), and α-substituted acetates (monochloroacetate and glycolate). Anation rate constants were obtained for glycine, β-alanine, and e-aminocaproic acid, and equilibrium constants between [CoH2O(NH3)5]3+ and [Co(NH3)5amH]3+ (amH=amino acid), Keq were calculated. The free energy plot logkaq vs. logKeq gave a straight line with a gradient 0.6. This value has been discussed in terms of two possible mechanisms. The dependence of acid catalysed aquation rate constant, kH+ on pKa of carboxylate group of the amino acid is written as logkH+=0.5 pKa+ const., while that for α-substituted acetates log kH+=pKa+ const. Such a difference in the slope is interpreted as due to the electrostatic influence of–NH3+ group of coordinated amino acid.