High-Resolution Near-Infrared Spectroscopy of CH2+ and Its Deuterated Isotopologues

Aiming to provide approximate rotational constants for millimeter Wave, spectroscopists to identify the corresponding species in Space, we have recorded the near infrared spectra of the methylene cation CH2+ and its deuterated isotopologues, CD2+ and CHD+, using a high resolution and high sensitivity spectrometer. Detection of CH2+ in space will shed light on interstellar chemistry as it is the intermediate between the abundant CH+ and yet to be observed CH3+, which is important in the formation of larger organic molecules. CH2+ and its deuterated isotopologues are also of special interest for theoretical studies because of their. unique intramolecular dynamics, i.e., the Renner-Teller interaction and quasi-linearity. This paper will discuss several new bands of CH2+, the (A) over tilde (0,5[11],0)(0) <-- <(X)over tilde>(0,0[0],0)(1) and (A) over tilde (0,4[11],0)(2) <-- <(X)over tilde>(0,0[0],0)(1) bands of CD2+, which have been identified and analyzed, and the candidate lines for the (A) over tilde (0,4[10],0)(1) <-- <(X)over tilde>(0,0[1],0)(0) band of CHD+, in comparison with the theoretical predictions by Bunker and colleagues.