Journal of Chemical Physics, Vol.117, No.11, 5252-5256, 2002
Tunable diode laser study of the nu(2) infrared band of fluoroketene: Confirmation of anomalously low C = O stretching frequency
The short-lived molecule fluoroketene (FHCCO) was generated by laser pyrolysis of fluoroacetyl chloride in a static multipass cell to record the first high-resolution infrared spectrum of its nu(2) fundamental band. More than 400 transitions between 2143 and 2160 cm(-1) were assigned and analyzed to yield very accurate rotational and centrifugal distortion constants for the upper vibrational state. The nu(2) band origin of fluoroketene lies at 2147.826 93 cm(-1), which is surprisingly low compared to the band origins of other ketenes. This result is confirmed by matrix isolation Fourier transform infrared spectroscopy of all four monohaloketenes.