The microwave frequencies have been reported by
(1) C. C. Costain and R. J. Morton, 1959, J. Chem. Phys. 31, 389.
Because of the very limited experimental data set, calculations were limited to J ≤ 5, and a-type transitions only. The entry may be sufficient for identifying the isotopolog in dark clouds. Predictions should be viewed with caution.
The dipole moment was assumed to agree with that of the main species, see e054510.cat.