Molecular structure of (CH3)3PF2 : An electron diffraction study of an analogue of ArF2

The molecule (CH3)3PF2 is a trigonal bipyramid with freely rotating methyl groups at the equatorial sites. The principal structural parameters and estimated standard deviations are rg(PF) = 1.685(1) A, rg(PC) = 1.813(1) A, and r(CH) = 1.114(6) A. Amplitudes of vibration were also determined. This investigation completes a study of the series (CH3)nPF5-n 0 [les] n [les] 3, and (CH3)3PF2 corresponds to the hypothetical molecule ArF2 in the closely related series PF5, SF4, ClF3 and ArF2. The stereochemistries and trends in structure parameters in both series are well accounted for by the Gillespie-Nyholm theory. A linear extrapolation suggests a bond length of 1.76 A for argon difluoride.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33953/1/0000223.pd