New substituted hydroxamic acids for spectrophotometric determination of cerium(IV).

Determination of pKa’s of hydroxamic acids by nucleophilic substitution reaction

Acid dissociation constant (pKa) of some para-substituted benzohydroxamic, 4-XC6H4CONHOH, and N-methyl parasubstituted benzohydroxamic acids, 4XC6H4CON(OH)CH3, where X = H, CH3, CH3O, NO2, Cl, have been determined spectrophotometrically by nucleophilic substitution reactions of pnitrophenyl acetate with hydroxamate ions at 27± 0.1C. All reactions in this study follow pseudo-first order kinetics...

New complexes of peroxidases with hydroxamic acids, hydrazides, and amides.

Horseradish peroxidase forms spectroscopically distinct, reversible complexes with hydroxamic acids (R-CONHOH), hydrazides (RCO-NHNH2), amides (RCONH2), and oc-hydroxyketones (RCO--CHsOH). Binding of these compounds to the enzyme depends on the polar and steric character of R and the hydrogen bonding capacity of-COX-Y (X-Y = NH-OH, NH-NH,, NH-H, CH,OH). Hydroxamate anions and hydrazide cations ...

Ethyl Maltol as a New Ligand for Spectrophotometric Determination of Iron

     In this study a new simple selective and sensitive spectrophotometric procedure for determination of Fe(III) is described. It is based on the formation of a colored complex between ferric iron and ethyl maltol, a strong and highly selective ligand for Fe(III). After mixing sample and reagent, and incubating at the room temperature, Fe(III)-ethyl maltol complex was extracted with different ...

Theoretical Studies on Hydroxamic Acids

Hydroxamic acids find many applications in chemistry and biology and have been the subject of many experimental investigations. Theoretical studies are not as frequent. However, the smallest homolog, formohydroxamic acid (FHA), has been studied at various levels, including high-level ab initio and density functional with large basis sets. All studies indicate that it exists as the Z-amide tauto...

New Reagents for the Spectrophotometric Determination of Hypochlorite