The structure of CF3PF4, indicated by the complete gashyphen;phase infrared spectrum from 4000 to 33 cmminus;1, is a trigonal bipyramid in which the CF3group assumes an equatorial position. The spectrum agrees with selection rules derived from theC2ugr;point group, or possibly from theC3point group, and all of the active fundamentals on the basis of aC2ugr;model were located. Raman spectra of the liquid from minus;70deg; to minus;115deg;C agree with the infrared results. The relative intensities and the frequencies obtained for the fundamentals of CF3PF4parallel those of the structurally related CH3PF4molecule. Although no evidence for aC3ugr;molecule was recorded, the presence of such a species in a dynamic exchange formalism is not precluded. In fact, the microwave results which favor such a species and the infrared and NMR results, when considered together, indicate an exchange process in which both the CF3group and the F atoms all participate. The exchange can be thought of as a collision stabilized process.
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