3085-45-8

The rates of catalytic oxidative decontamination of the chemical warfare agent (CWA) sulfur mustard (HD, bis(2-chlororethyl) sulfide) and a range (chloroethyl) sulfide simulants of variable lipophilicity have been examined using a hydrogen peroxide-based microemulsion system. SANS (small-angle neutron scattering), SAXS (small-angle X-ray scattering), PGSE-NMR (pulsed-gradient spin-echo NMR), fluorescence quenching, and electrospray mass spectroscopy (ESI-MS) were implemented to examine the distribution of HD, its simulants, and their oxidation/hydrolysis products in a model oil-in-water microemulsion. These measurements not only present a means of interpreting decontamination rates but also a rationale for the design of oxidation catalysts for these toxic materials. Here we show that by localizing manganese-Schiff base catalysts at the oil droplet-water interface or within the droplet core, a range of (chloroethyl) sulfides, including HD, spanning some 7 orders of octanol-water partition coefficient (Kow), may be oxidized with equal efficacy using dilute (5 wt. % of aqueous phase) hydrogen peroxide as a noncorrosive, environmentally benign oxidant (e.g., t1/2 (HD) ～ 18 s, (2-chloroethyl phenyl sulfide, C6H5SCH2CH 2Cl) ～ 15 s, (thiodiglycol, S(CH2CH 2OH)2) ～ 19 s {20°C}). Our observations demonstrate that by programming catalyst lipophilicity to colocalize catalyst and substrate, the inherent compartmentalization of the microemulsion can be exploited to achieve enhanced rates of reaction or to exert control over product selectivity. A combination of SANS, ESI-MS and fluorescence quenching measurements indicate that the enhanced catalytic activity is due to the locus of the catalyst and not a result of partial hydrolysis of the substrate.

Chloramine-T, sodium N-chlorotoluene-p-sulphonamide reacts with 2,2'-thiodiethanol in weakly acidic methanol to yield 2,2'(p-tolylsulphonylimino-λ4-sulphanyl)diethanol monohydrate, MeC6H4-SO2NS(CH2CH2OH)2*H2O (1) and 2,2'-sulphinyldiethanol, OS(CH2CH2OH)2 (2), in yields of 23 and 36percent respectively.Crystals of (1) are monoclinic, space group P21/c, with a = 7.497(1), b = 16.291(2), c = 11.843(2) Angstroem, β = 92.52(1) deg, and Z = 4.The structure was refined from diffractometer data to an R value of 0.033.The structure consists of a hydrogen-bonded array of MeC6H4SO2NS(CH2CH2OH)2 molecules and of water molecules, in which each molecule participates in three hydrogen bonds.Within the MeC6H4SO2NS(CH2CH2OH)2 molecules the S(VI)-N and N-S(IV) bond lengths are 1.602(2) and 1.629(2) Angstroem, and there is a short intramolecular O...S contact distance of 2.931 Angstroem.The structural data indicate a highly polarised, ylidic, molecule.Crystals of (2) are monoclinic, space group P21/n with a = 11.057(4), b = 4.837(2), c = 12.332(4) Angstroem, β = 103.61(3) deg, and Z = 4.The crystals are always twinned, but by careful photographic and diffractometer studies a complete structural analysis was possible; R = 0.044 from 1056 diffractometer data.The structure contains OS(CH2CH2OH)2 molecules which are not maximally extended but which are linked by O-H...O hydrogen bonds to form centrosymmetric dimers, further linked into infinite spirals.The sulphur atom in (2) is pyramidal with an S-O distance of 1.514(3) Angstroem and S-C dictances of 1.789(3) and 1.791(3) Angstroem.