High Resolution Infrared Detection of O=PF in the Gas Phase

Abstract

Short-lived phosphenous fluoride, 0=PF, has been made by flash pyrolysis of F 2 POPF 2 in Ar at 1200°C and detected by gas phase IR spectroscopy. The v x band, v 0 = 1297.5372 cm -1 , has been studied with a resolution of 8 x 10 -3 cm -1 , and about 1500 transitions have been assigned. These were fitted using a Watson-type Hamiltonian, cr = 1.5 x 10 -3 cm -1 , to excited state parameters up to quartic centrifugal distortion constants. The v> 2 band was located at 819.58 cm -1 . An extended set of ground state parameters was obtained by combining recently measured microwave transitions with ground state combination differences formed from v x transitions.The experimental results are in perfect agreement with the matrix IR spectra, mw measurements and ab initio calculations but disagree with a recently claimed low resolution detection of OPF in the gas phase.

IR Spectroscopy of OP−X and Derivatives: Mistaken Identity on a Large Scale

“…We note also that the precursor spectrum of Figure in ref is not that of OPCl 3 , as claimed. This was pointed out earlier by Paplewski et al, who suggested that the molecule might be hexamethyldisiloxane resulting from degradation of the silicone grease . The observed IR spectrum, however, exactly matches octamethylcyclotetrasiloxane .…”

Millimeter-wave spectroscopy, high resolution infrared spectrum, ab initio calculations, and molecular geometry of FPO

“…In conjunction with a slightly higher oven temperature the average concentration of FPO in the IR beam with regard to ref. 13 was about the same (ca. 3 ] 1013 molecules cm~3) in spite of a total pressure (due to Ar and by-products) that was lower by a factor of 4.…”

“…was investigated at a resolution of 0.008 cm~1, and about 1500 transitions were assigned and Ðtted with p \ 0.0015 cm~1. 13 Since a productive and continuous Ñow of FPO had to be maintained for longer time we developed a synthesis13 that is more suitable than the reported heterogeneous reaction of with Ag just below the melting point of the latter OPFBr 2 (962 ¡C). In analogy to the generation of by Ñash pyro-SSiF 2 lysis of at P500 ¡C15 we Ñash-pyrolyzed F 3 SiSSiF 3 in Ar at 120 ¡C.13 F 2 POPF 2 16…”

Millimeter-Wave Spectroscopy, High-Resolution Infrared Spectrum, ab Initio Calculations, and Molecular Geometry of FPS

“…In analogy to the generation of SSiF 2 (27) and OPF (22,23) by flash pyrolysis of F 3 SiSSiF 3 and F 2 POPF 2 , respectively, FPS has been obtained from F 2 PSPF 2 in Ar at temperatures higher than 1400…”