Reactions of VX, GB, GD, and HD with nanosize Al2O3.: Formation of aluminophosphonates

Room-temperature reactions of VX, GB, GD, and HD with nanosize Al2O3 (AP-Al2O3) have been characterized by P-31, C-13, and Al-27 MAS NMR. Nerve agents VX, GB, and GD hydrolyze to yield surface-bound complexes of their corresponding nontoxic phosphonates. At sufficiently high loadings, discreet aluminophosphonate complexes, Al[OP(O)(CH3)OR](3), are generated which are identical to synthesized model compounds. Thus the reaction with phosphonic acids is not just surface-limited, but can continue to the core of alumina particles. HD mainly hydrolyzes at lower loadings to yield thiodiglycol (TG, 71%) and a minor amount of the CH-TG sulfonium ion (12%), although some elimination of HCl is also observed (17%). The reactive capacity for HD is evidently exceeded at high loadings, where complete conversion to TG is hindered. However, addition of excess water results in the quantitative hydrolysis of sorbed HD to CH-TG. On AP-Al2O3 dried to remove physisorbed water, C-13 CP-MAS NMR detects a surface alkoxide consistent with that of TG.