Reaction between U(IV) and H₂O₂ in hydrochloric acid medium

Abstract

Kinetic investigations on the reaction between U(IV) and H202 have been carried out a t different acidities in chloride medium a t an ionic strength of 2M. The observed bimolecular rate constant has been found to be dependant on [H+]-1.3. The activation energy of the overall reaction has been found to vary from 13.4 * 0.7 to 18.0 f 0.8 kcal/mol in the range of acidity from 0.3 to 1.5M. The results have been explained on the basis of three parallel rate-controlling reactions involving unhydrolyzed species of U(IV) and hydrolyzed species UCl(OH)2+ and U02+. The values of the rate constants for these three reaction paths have been found to be of the order of 3.95,5.59 X lo3, and 1.49 X 105M-' min-', respectively.

Stabilization of the T‐state of human hemoglobin by proflavine, an antiseptic drug

“…The oxygen binding and spectroscopic properties of ferrous human adult hemoglobin (Hb) are modulated physiologically by heterotropic effectors, such as 2,3-D-glycerate bisphosphate, inorganic phosphate, chloride ions, carbon dioxide and protons. A similar effect has been reported for synthetic compounds displaying pharmaceutical activity, such as the anti-hyperlipidemic drugs bezafibrate and clofibric acid, as well as the anti-psychotic tranquilizer chlorpromazine [1][2][3][4][5][6].…”

“…Such a pattern has been interpreted in terms of a more significant stabilization of the low affinit3~ state of nitrosylated hemoproteins [5,17,18]. The reversible allosteric effector-induced spectroscopic changes occurring in ferrous human adult HbNO (see Accordingly, chlorpromazine, a drug structurally related to proflavine, interacts with tryptophan residues of the tetramer [4].…”