FT-IR and FT-NMR Study of Organophosphorus Surface Reactions
Abstract:Fourier transform infrared (FT-IR) and Fourier transform nuclear magnetic resonance (FT-NMR) methods were used to examine the adsorption and reaction of diisopropyl fluorophosphate (DFP) on various solid adsorbents. Static and flow system experiments were monitored with the use of FT-IR to determine DFP adsorption rates and isotherms on silica, coated silicas, γ-alumina, coated aluminas, and activated charcoal. The adsorption of DFP(g) onto the solid adsorbents was generally very rapid, with a half-life of 20 s for 1 mg DFP onto 25 mg of 350 m2/g silica. The DFP adsorption isotherm on silica indicated chemisorption to a monolayer at P/P 0 < 0.6, followed by increased coverage that appears to be physical adsorption. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, photoacoustic spectroscopy (PAS), and solid-state 31P NMR of adsorbed DFP showed chemisorption on silica and on alumina. Bonding at the P=O of DFP was indicated by a −41 cm−1 shift in the ν(P=O) and a 1-ppm upfield shift in the 31P resonance. DRIFT, PAS kinetics, and 31P NMR showed that DFP hydrolyzed after the initial adsorption on alumina and some coated materials but not on silica or activated charcoal. The rate of hydrolysis increased on alumina with addition of water and varied with different aluminas and coated silicas.
Document Type: Research Article
Affiliations: Chemistry Division, Research Department, Naval Weapons Center, China Lake, California 93555-6001
Publication date: May 1, 1988
More about this publication?
- The Society publishes the internationally recognized, peer reviewed journal, Applied Spectroscopy, which is available both in print and online. Subscriptions are included with membership or can be purchased by institutional or corporate organizations. Abstracts may be viewed free of charge. Previously published as Bulletin (Society for Applied Spectroscopy)
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Request copyrighted SAS materials
- Spectroscopic Nomenclature
- Focal Point (Open Access)
- ingentaconnect is not responsible for the content or availability of external websites