Identification of the isomeric forms of lewisite using mass spectrometry, nuclear magnetic resonance and infrared spectroscopy, and molecular modeling

Technical Report · Thu May 13 04:00:00 EDT 1993

OSTI ID:7310083

Smith, J R; Logan, T P; VonTersch, R L; Jakubowski, E M; Dolzine, T W

our research has identified a previously unreported form of lewisite, a geminal isomer. We have attempted to characterize this isomer along with the previously reported geometric isomers of lewisite using several spectroscopic methods and a molecular modeling program. Proton NMR produced a coupling constant consistent with vinylic protons in a geminal configuration. Attempts at examining the geminal isomer using proton coupled 13C NMR were unsuccessful due to the small percentage of the geminal isomer in the neat material. The direct injection of lewisite onto a gas chromatograph resulted in a variety of deleterious effects that were observed after only a few injections. Therefore the gas chromatographic separation and subsequent detection by mass spectrometry and infrared spectroscopy was based on an ethanedithiol derivative of the lewisite. The mass spectra of the trans and cis derivatives were very similar, but the gem form displayed significant differences. The sensitivity of the infrared method employed only produced spectra for the trans and gem derivatives with significant differences observed between the two. Molecular modeling calculations indicate that the trans and cis stereoisomers have similar dipole moments while the geminal isomer has a slightly higher dipole moment.

• Research Organization: Army Medical Research Inst. of Chemical Defense, Aberdeen Proving Ground, MD (United States)
• OSTI ID: 7310083
• Report Number(s): AD-P-008790/8/XAB
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
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DETECTION
ISOMERS
WEAPONS