ORGANIC SPECTROSCOPY INTERNATIONAL: 31P spectrum

This is the ³¹P spectrum. The scale is Hz. This spectrum shows the expected septuplet pattern of peaks having integrated intensities of 1:6:15:20:15:6:1 resulting from the splitting of the phosphorous atom by the six equivalent I=1/2 ¹⁹F nuclei. The coupling constant, J_PFwas found experimentally to be 714 Hz, very similar to the value listed above.

The ¹⁹F and ³¹P FT-NMR Spectra

This is the Free Induction Decay Curve for the ¹⁹F spectrum.

This is the ¹⁹F spectrum. The scale is Hz. This spectrum shows the expected doublet pattern of peaks having equal integrated intensities resulting from the splitting of the six equivalent flourine atoms by the I=1/2 ³¹P nucleus. The coupling constant, J_PFwas found experimentally to be 717 Hz.

The Vibrational Spectrum

This vibrational spectrum was calculated by Hyperchem. The vibrations predicted by Hyperchem are at (in cm^-1): 219, 376, 470, 851, 974, and 1292. These correspond to the following examples of normal modes of vibration (in respective order):

v₆(t_2u) v₅(t_2g)

v₄(t_1u) v₂(e_g)

v₁(a_1g) v₃(t_1u)

In comparison with literature values from Kazuo Nakamoto's Infrared and Raman Spectra of Inorganic and Coordination Compounds; 5th ed.; Part A; page 216, these vibrations are at (in cm^-1): not available, 480~468, 559;530, 585;570, 756, and 865;835. Note the splitting of three of the spectral lines. It appears that many Hyperchem lines were calculated higher than the experimental values. This is consistent with the nature of these semi-empirical calculations (AM1). The symmetry labels above were obtained through comparison of the Hyperchem normal modes with those found in Nakamoto, p. 215. These modes were found by Hyperchem to be triply degenerate with the exceptions of v₃(t_1u) and v₁(a_1g) which were doubly and nondegenerate, respectively.

The Electronic Spectrum