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Reactivity of Hydroxamate Ions in Cationic Vesicular Media for the Cleavage of Carboxylate Esters
Author(s) -
Kandpal Neha,
Dewangan Hitesh K.,
Nagwanshi Rekha,
Vaishanav Sandeep K.,
Ghosh Kallol K.,
Satnami Manmohan L.
Publication year - 2017
Publication title -
journal of surfactants and detergents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.349
H-Index - 48
eISSN - 1558-9293
pISSN - 1097-3958
DOI - 10.1007/s11743-016-1919-3
Subject(s) - chemistry , carboxylate , cationic polymerization , vesicle , bromide , pyrene , hydrolysis , enthalpy , reactivity (psychology) , medicinal chemistry , pulmonary surfactant , inorganic chemistry , organic chemistry , nuclear chemistry , membrane , biochemistry , medicine , physics , alternative medicine , pathology , quantum mechanics
The hydrolysis of carboxylate esters viz. p ‐nitrophenyl acetate (PNPA), p ‐nitrophenyl butyrate (PNPB) and p ‐nitrophenyl octanoate (PNPO) in the presence of cationic vesicles of the surfactant dioctadecyldimethylammonium bromide (DODAC) by different hydroxamate ions i.e. acetohydroxamate (AHA − ), benzohydroxamate (BHA − ) and salicylhydroxamate (SHA − ) were studied. The kinetic data was supported by spectrophotometric measurements. The effects of vesicular size on the reaction have been discussed. The differential reactivity under endo‐ and exovesicular conditions has also been evaluated. Critical vesicle concentrations (CVC) of cationic vesicular surfactants were determined from conductometric and fluorimetric measurements at 300 K. Fluorescence probe pyrene and pyrene‐1‐carboxaldehyde have been used for determination of CVC. Further, thermodynamic parameters viz. Standard Gibb's energy (∆ G °), enthalpy (∆ H °), and entropy (∆ S °) of vesicles has also been evaluated within a temperature range of 303.15–328.15 K.