Collect. Czech. Chem. Commun. 1997, 62, 1342-1354

Metallomicellar Hydrolytic Catalysts Containing Ligand Surfactants Derived from Alkyl Pyridin-2-yl Ketoxime

Radek Cibulka, David Dvořák, František Hampl and František Liška

Department of Organic Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6, Czech Republic


N-Hexyl- (2a), N-octyl- (2b), N-decyl- (2c) and N-dodecyl-N-[2-(hydroxyimino)-2-(pyridin-2-yl)ethyl]dimethylammonium (2d) nitrates were synthesized as water-soluble cationic ligand surfactants. Three types of micellar catalytic systems employing salts 2 were prepared: homomicellar water solutions of salts 2, comicellar solutions of salts 2 with an inert cationic tenside hexadecyltrimethylammonium bromide (CTAB) and comicellar systems consisting of complexes of ligand surfactants 2 with transition metal ions (Co(II), Ni(II), Cu(II) and Zn(II)) and CTAB. Hydrolytic efficiency of all micellar and metallomicellar systems was tested by measuring the kinetics of the model substrate cleavage under pseudo-first-order reaction conditions. Of the above-mentioned catalysts, comicellar systems of salts 2 comicellized with CTAB were most efficient. In all cases, with the exception of Zn(II), coordination of a metal ion decreased the hydrolytic efficiency of salts 2.

Keywords: Ester hydrolysis; Ligand surfactant; Micellar catalysis; Pyridine derivatives.