US EPA

1618108 

Journal Article 

A chemical comparison of methanesulfonyl fluoride with organofluorophosphorus ester anticholinesterase compounds 

Snow, AW; Barger, WR 

1988 

Yes 

Chemical Research in Toxicology
ISSN: 0893-228X
EISSN: 1520-5010 

NIOSH/00184843 

1 

6 

379-384 

English 

2979754 

The chemical reactivity and physical properties of methanesulfonyl fluoride (MSF) were quantitatively measured for direct comparison with those of isopropyl methylphosphonofluoridate (GB, sarin) and diisopropyl phosphorofluoridate (DFP). The chemistry involved reaction rate constant measurements of MSF hydrolysis and for reactions with phenolic, amine, oxime, hydroxamic acid, phenyl N-hydroxycarbamate, and hydroxylamine compounds and cupric imidazole and bipyridyl complexes. Analogous chemistry with GB and DFP occurred only for the nucleophilic reactions. MSF was substantially less reactive toward interactions involving hydrogen bonding, cupric complex coordination, and quaternary amine formation. Physical characterization included water solubility, vapor pressure, heat of vaporization, solubility parameter, hydrogen bond basicity, UV, IR, and NMR measurements. MSF is a much weaker hydrogen bond acceptor than the phosphorus esters. The hydrogen bond basicity beta-scale measurement provides a key insight to the chemical reactivity divergence of MSF and DFP or GB. Its unexpectedly low value is interpreted that MSF does not possess a site with sufficient basicity to be protonated by strong acid, to enter into hydrogen bonding, or for coordination with the cupric ion. 

DCN-176799; Chemical structure; Enzyme activity; Fluorides; Cholinesterase inhibitors; Chemical properties