The millimeter-wave spectrum of methoxyacetonitrile

This paper is the second as part of a study to elucidate cyano group chemistry in the interstellar medium, wherein we present a characterization of the millimeter-wave spectrum of methoxyacetonitrile. Its structural isomer, 2-cyanoethanol was described in paper Braakman and Blake (submitted for publication) [1]. The rotational spectrum of methoxyacetonitrile shows the characteristics of a well-behaved asymmetric rigid-rotor. We assigned nearly 7400 transitions to 2 conformers and 2 excited states. All were fit to Watson A-reduced Hamiltonians, including only the effects of centrifugal distortion. The lowest energy states are fit close to experimental accuracy, with a gradual decrease in quality for higher energy states. No repulsive interactions are apparent. The measurements and predictions from the fits reported here are being used as a basis for observational studies of this species.