Theory and Synthesis of New HEDM Related Materials
Abstract
This paper describes some of the work carried out during the past year by both the HEDM Synthesis Group at the Phillips Laboratory and the associated program at USC, which is partially supported by the Air Force. It exemplifies the benefits and synergism which can be derived from the successful combination of theory and synthesis. In the area of novel anions, our study of the novel and elusive POF4 (-) anion was completed. This anion, which is stable only at -140 deg C, was characterized, in collaboration with Prof. Schrobilgen from McMaster University, by multinuclear NMR spectroscopy. In collaboration with Dr. Dixon from Pacific Northwest Laboratories, the geometry, NMR shifts, activation barriers for the Berry inversion, vibrational spectra, force field and thermodynamic data were calculated. In the course of our efforts to rationalize the very different dismutation behavior of PO4(-) and isoelectronic SOF4, (PF4(-) dismutates at -140 deg C to PO2F2(-) and PF6(-), whereas SOF4 does not dismutate at all to SO2F2 and SF6), it was shown by our ab initio calculations that the thermodynamic data published for several phosphorus and sulfur oxofluorides are in error by as much as 60 kcal/mol. It was shown that the different dismutation behavior of POF4(-) and SOF4 is due to mechanistic and not thermodynamic reasons. The results were published in the Journal of the American Chemical Society, 1997,119,3918.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 24, 1998
- Accession Number
- ADA397993
Entities
People
- Gregory W. Drake
- J. Sheehy
- Karl O. Christe
- M. Petrie
- William L. Wilson
Organizations
- Air Force Research Laboratory