High resolution infrared detection of O=PF in the gas phase

Short-lived phosphenous fluoride, O=PF, has been made by flash pyrolysis of F2POPF2 in Ar at 1200 degrees C and detected by gas phase IR spectroscopy. The nu(1) band, v(0) = 1297.5372 cm(-1), has been studied with a resolutio n of 8 x 10(-3) cm(-1), and about 1500 transitions have been assigned. Thes e were fitted using a Watson-type Hamiltonian, sigma = 1.5 x 10(-3) cm(-1), to excited state parameters up to quartic centrifugal distortion constants . The nu(2) band was located at 819.58 cm(-1). An extended set of ground st ate parameters was obtained by combining recently measured microwave transi tions with ground state combination differences formed from nu(1) transitio ns. The experimental results are in perfect agreement with the matrix IR spectr a, mw measurements and ab initio calculations but disagree with a recently claimed low resolution detection of OFF in the gas phase.