High Resolution Infrared Study of the ν11 Level in H2C[]13C[]CH2

The lowest fundamental level ν11 in 2-13C-allene, H2C[]13C[]CH2, has been studied from a high resolution infrared spectrum of the ν11 band together with lower state combination differences obtained from high resolution infrared measurements of the hot bands ν7 + ν11 − ν11, ν9 + ν11 − ν11, ν10 + ν11 − ν11, and 2ν10 + ν11 − ν11. From a simultaneous analysis of 4592 energy levels and combination differences for the ν11 level a set of spectroscopic constants has been obtained with a model taking into account the two types of rotational l-type resonance allowed for this molecule. Subband constants for the various hot bands ν7 + ν11 − ν11, ν9 + ν11 − ν11, ν10 + ν11 − ν11, and 2ν10 + ν11 − ν11 assigned in this study are summarized in tables.