The high resolution infrared spectrum of the ν₉, ν₆ and ν₅ bands in ketene-d₂

Abstract

The three lowest fundamental bands v ₉, v ₆ and v ₅ of D₂CCO have been studied at a resolution of ca. 0·003 cm^-1 from infrared spectra obtained at room temperature. A set of high quality ground state rotational and centrifugal distortion constants has been obtained. From an analysis of infrared ground state combination differences together with the microwave and millimeterwave measurements of Nemes and Winnewisser [6] we obtained the following rotational ground state constants:

A global analysis of the three bands taking into account first and second order Coriolis interactions within the tetrad v ₉, v ₆, v ₅, v ₈ yielded spectroscopic constants for the v ₉, v ₆ and v ₅ levels as well as a number of interaction parameters. The hot bands 2v ₉ - v ₉, v ₉ + v ₆ - v ₉, 2v ₆ - v ₆, and the difference band v ₄ - v ₆ have been identified. Some information on the levels v ₉ = 2, v ₉ = v ₆ = 1, v ₆ = 2, and v ₄ = 1 has been derived from these bands.