Rotational spectroscopy of the SrNH2 and SrND2 radicals (X̃2A1)

The pure rotational spectrum of the SrNH2 radical in its X̃2A1 state has been recorded using sub-millimeter direct absorption techniques in the range 225–540 GHz. Measurements of SrND2 have also been conducted. Both molecules were produced by the reaction of metal vapor and NH3 or ND3. Fourteen and fifteen rotational transitions were recorded for SrNH2 and SrND2, respectively. Asymmetry doublets for Ka=0 through 5 or 6, as well as fine structure splittings, were observed in every transition. From these data, spectroscopic constants have been determined, as well as an r0-structure. This study provides additional evidence that SrNH2 is planar with ionic bonding.