The room temperature chemistry of organo-sulfur esters with NaX zeolite

Small organo-sulfur esters, which are common alkylating agents, are highly toxic compounds and have been proposed as possible chemical warfare agents. Previous studies have shown that dry, high Al content, X type zeolites have tetrahedral Al centers that exhibit nucleophilic properties that are of interest in chemical decontamination. This work examines the nucleophilic chemistry of representative small organo-sulfur esters with tetrahedral Al centers in NaX zeolite. Two sulfite esters and a sulfate and sulfonate ester were chosen as representatives.The chemistries of all representatives with the tetrahedral Al centers of NaX were found to be remarkably similar, namely the alkylation of the O atoms of the Al tetrahedra on the supercage surface of the zeolite to form a framework alkoxy species and the sodium salt of the acid of the corresponding organo-sulfur ester. Partial hydrolysis of the products was found, with the formation of the alcohol from the framework alkoxy specie and a Brønsted acid tetrahedral Al site in the zeolite. No hydrolysis of the anions of the salts was observed.

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► X Faujasite zeolite nucleophilic to organo-sulfur esters.
► Examined ethyl and ethyl sulfate, sulfite, and sulfonate esters.
► Formation of salt of the de-esterified ester and a framework carbocation adduct.
► Carbocation but not salt hydrolysis observed.
► Chemical decontamination applications.