Nucleophilicity of aromatic and aliphatic hydroxamate ions towards C=O and P=O center in cationic micellar media

School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur-492 010, Chhattisgarh, India
Department of Chemistry, Govt. Madhav Science P.G. College, Ujjain-456 010, Madhya Pradesh, India
E-mail : manmohanchem@gmail.com
Manuscript received online 26 June 2015, accepted 13 August 2015

The kinetics of the hydrolysis of p-nitrophenyl benzoate (PNPB) and p-nitrophenyldiphenyl phosphate (PNPDPP) by hydroxamate ions (R´(C=O)N(RO^–)) have been investigated in aqueous cationic micellar media at pH 6.5 to 12.0 and 27 ºC. The pseudo-first order rate constants-surfactant profiles show micelle assisted bimolecular reaction involving an interfacial exchange between bulk aqueous media and micellar pseudophase. All the hydroxamate ion shows higher reactivity in cationic micellar media. Pseudophase model has been applied in order to determine micellar second order rate constant and binding constant.