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Mesoporous copper–titanium dioxide (Cu/TiO2) composite aerogels with <5-nm-diameter copper (Cu) nanoparticles hydrolyze the chemical warfare (CW) simulant dimethyl methylphosphonate (DMMP) under aerobic and anaerobic conditions. After Cu/TiO2 is exposed to DMMP in an in situ diffuse-reflectance infrared Fourier transform spectroscopy (DRIFTS) reaction chamber, hydrolysis products (i.e., methoxy groups) are bound to the surface, while no intact DMMP is observed. In contrast, DMMP degradation is not observed under our DRIFTS reactor conditions at native TiO2 aerogels, CuO, or Cu2O nanoparticles. We attribute the hydrolytic activity of Cu/TiO2 aerogels to a high surface concentration of OH species that form at Cu||TiO2 junctions. Neither hydrolysis of DMMP nor excess surface OH is observed on Au/TiO2 aerogels. The poor ability of the Au||TiO2 interface to activate water relative to that of the Cu||TiO2 interface suggests that a readily reducible supporting oxide is insufficient to promote an excess population of surface OH speciesthe supported nanoparticle must be sufficiently redox-active as well. Under aerobic conditions, DMMP hydrolysis is accelerated on Cu/TiO2, suggesting that O2 promotes the formation and turnover of surface OH sites. The general materials design demonstrated here of a Cu nanoparticle/reducing oxide aerogel is a promising route to CW decontamination as well other surface-mediated chemistries requiring the activation of water. [ABSTRACT FROM AUTHOR]

A wide range of chemical warfare agents and their simulants are catalytically decontaminated by a new one-dimensional polymeric polyniobate (P-PONb), K12[Ti2O2][GeNb12O40]⋅19 H2O ( KGeNb) under mild conditions and in the dark. Uniquely, KGeNb facilitates hydrolysis of nerve agents Sarin (GB) and Soman (GD) (and their less reactive simulants, dimethyl methylphosphonate (DMMP)) as well as mustard (HD) in both liquid and gas phases at ambient temperature and in the absence of neutralizing bases or illumination. Three lines of evidence establish that KGeNb removes DMMP, and thus likely GB/GD, by general base catalysis: a) the k(H2O)/k(D2O) solvent isotope effect is 1.4; b) the rate law (hydrolysis at the same pH depends on the amount of P-PONb present); and c) hydroxide is far less active against the above simulants at the same pH than the P-PONbs themselves, a critical control experiment. [ABSTRACT FROM AUTHOR]

Abstract: Acetylcholinesterase (AChE) is an interesting research target not only because of its high enzyme catalytic rate but also because of the wide range of health effects resulting from its inhibition. This paper discusses results of a theoretical study of acetylcholinesterase inhibition using several simulation techniques. In the first technique, a novel method was developed and used for predicting the binding affinity of human AChE (huAChE) inhibitors. Results are also presented for classical molecular dynamics and quantum mechanical simulations. Theoretical proton NMR shift results are obtained and compared to experiment, and the importance of the Glu199 residue is discussed in the context of the model. [Copyright &y& Elsevier]

Inexpensive strategies for efficient decontamination of hazardous chemicals are required. In this study, the effect of visible light (λ > 400 nm) on the decomposition of 2-chloroethyl ethyl sulfide (2-CEES, a sulfur mustard (HD) simulant) on Au/TiO2 photocatalyst under anaerobic and aerobic conditions has been investigated in situ by diffuse reflectance infrared Fourier –transformed spectroscopy (DRIFTS). Under anaerobic conditions, 2-CEES partially desorbs from the Au/TiO2 surface likely due to the photothermal effect, induced by photo-excited plasmonic Au nanoparticles. In the aerobic experiment, no visible light effect is observed. We attribute this behavior to 2-CEES consumption by hydrolysis to 2-ethylthio ethanol in the dark, prior to visible light excitation. Oxygen activates water molecules in the dark, resulting in accelerated 2-CEES hydrolysis. [ABSTRACT FROM AUTHOR]