Rapid Oxidative Detoxification of Mustard Simulant by the Multisite Synergistic Catalytic Action of {PMo^VI₁₁Mo^VO₄₀Cu^I₈} Units

Abstract

Under hydrothermal and solvent-thermal conditions, we synthesized two novel polyoxometalate (POM)-based hybrids: [Cu I 4 (Pz) 2 (H 2 O) 8 (PMo VI 11 Mo V O 40 )]• 3.5H 2 O (1, Pz = pyrazine) and [(C 2 H 8 N) 5 (HPMo VI 9 Mo V 3 O 40) ]•DMF•4H 2 O (2). Single-crystal X-ray diffraction indicates that compound 1 is a three-dimensional structure consisting of Cu (I), {PMo 12 } anions, Pz, and water, where Cu (I) can be considered as Lewis acid sites. Furthermore, both compounds 1 and 2 possess favorable catalysis activity in catalyzing the conversion of chemical warfare agent simulant 2chloroethylethyl sulfide (CEES) to nontoxic production of 2-chloroethylethyl sulfoxide (CEESO) under ambient temperature. Significantly, 1 could realize 98% conversion and 100% selectivity of CEES owing to the multisite synergy in the {PMo VI 11 Mo V O 40 Cu I 8 } units in which the tricoordinated Cu (I) could interact with S and O atoms from CEES and H 2 O 2 , respectively. This interaction not only decreases the distance of CEES from peroxomolybdenum species formed by H 2 O 2 but also activates CEES.

Selective and Efficient Detoxification of Sulfur Mustard Gas Analogues with H2O2 Using Bioinspired Mo and W Dithiolene Catalysts

“…In biological systems, selective oxygen atom transfer (OAT) reactions are catalyzed by oxotransferase enzymes − whose active sites feature bis­(dithiolene) ligation to Mo (and sometimes W) , via the pyranopterin dithiolate cofactor. Particularly relevant to the SM problem is biological dimethyl sulfoxide reduction, i.e., the microscope reverse of sulfide oxidation, which is catalyzed by the DMSO reductase enzyme whose Mo­(dithiolene) 2 active site (Figure b) is proposed to shuttle between Mo IV and Mo VI O states during OAT catalysis. − Accordingly, synthetic oxomolybdenum­(VI) compounds have been studied for catalytic OAT reactions including sulfur oxidations. − A prototypical example, commercially available MoO 2 (acac) 2 (acac = acetylacetonate), efficiently catalyzes oxidations of sulfoxides to sulfones and is representative of the challenge of taming the oxidizing power of high-valent Mo and W catalysts to avoid overoxidation of SM to SMO 2 . Despite extensive synthetic modeling literature of the DMSO reductase active site and related Mo/W enzymes such as sulfite oxidases, aldehyde oxidoreductases, and trimethyl N -oxide reductases, ,− the use of close structural mimics of oxotransferases featuring bis­(dithiolene) ligation to Mo or W in catalytic OAT reactions of sulfides has not yet been reported.…”