MILLIMETER-WAVE LABORATORY DETECTION OF H2COH+

The ground-state rotational spectrum of protonated formaldehyde, H2COH +, has been identified and assigned following the infrared detection b y Amano and Warner using a magnetically confined extended negative glo w discharge as a production source. The molecular constants have been determined more accurately. These parameters provide the pure rotation al transition frequencies that are accurate enough for radio astronomi cal searches for this ion in interstellar molecular clouds.