Hydrolysis of 4-Nitrophenyl Diphenyl Phosphate Assisted by Tetraminecobalt(III) in Microemulsion Media

Abstract

Reactions of hydroxoaquatetraminecobalt(III) in microemulsion media towards hydrolysis of 4-nitrophenyl diphenyl phosphate (NPDPP) were investigated at 10 ^{- 4} M concentration in several oil-in-water microemulsions. The reactions were monitored by measuring the absorbance of the nitrophenolate ion produced in the reaction aliquots with time. The amount of nitrophenolate ion was then determined from a calibration curve and the percentage hydrolysis calculated. The order of effectiveness of the N ₄ ligand in Co(III)(N ₄ )(aq) complexes at pH 6.5 towards hydrolysis of NPDPP was found to be trpn > (tn) ₂ > (en) ₂ (where trpn is tris(3-aminopropyl)amine, tn is trimethylenediamine, and en is ethylenediamine). The possible application of the above systems to environmental clean-up problems is discussed.