A Polyoxoniobate-Polyoxovanadate Double-Anion Catalyst for Simultaneous Oxidative and Hydrolytic Decontamination of Chemical Warfare Agent Simulants

摘要

A novel double-anion complex, H-13[(CH3)(4)N](12-)[PNb12O40((VO)-O-V)(2)center dot((V4O12)-O-IV)(2)]center dot 22H(2)O (1), based on bicapped polyoxoniobate and tetranuclear polyoxovanadate was synthesized, characterized by routine techniques and used in the catalytic decontamination of chemical warfare agents. Under mild conditions, 1 catalyzes both hydrolysis of the nerve agent simulant, diethyl cyanophosphonate (DECP) and selective oxidation of the sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES). In the oxidative decontamination system 100% CEES was transformed selectively to nontoxic 2-chloroethyl ethyl sulfoxide and vinyl ethyl sulfoxide using nearly stoichiometric 3% aqueous H2O2 with a turnover frequency (TOF) of 16 000 h(-1). Importantly, the catalytic activity is maintained even after ten recycles and CEES is completely decontaminated in 3 mins without formation of the highly toxic sulfone by-product. A three-step oxidative mechanism is proposed.