Quaternary ammonium O,O′-dialkylphosphorodithioate surfactants and their reactions with 2-chloroethyl phenyl sulfide, a mustard simulant

Single- and double-chain quaternary ammonium O,O′-dialkylphosphorodithioate surfactants 1–3 were synthesized: 1, hexadecyltrimethylammonium O,O′-diethylphosphorodithioate; 2a, didodecyldimethylammonium O,O′-dimethylphosphorodithioate; 2b, didodecyldimethylammonium O,O′-diethylphosphorodithioate; 3, didodecyldimethylammonium O,O′-didodecylphosphorodithioate. Surfactant 1 was characterized by Krafft temperature and critical micelle concentration measurements, and its aqueous aggregates were characterized by dynamic laser light scattering and 1H NMR spectroscopy. Compounds 2 and 3 are largely insoluble in H2O, even at temperatures >23 °C. The reaction of micellar 1 with 4 (2-chloroethyl phenyl sulfide), a simulant for the chemical warfare agent mustard [bis(2-chloroethyl) sulfide], gave 10 [S-[2-(phenylthio)ethyl] O,O′-diethylphosphorodithioate] in a pH 9.0 borate buffer at 23 °C. The conversion of 4 into 10 corresponds to the decontamination of 4.