Hydroxycarbene /HCOH/ and protonated formaldehyde - Two potentially observable interstellar molecules

Abstract

It is known that the lowest energy isomer of protonated formaldehyde has the proton attached to the oxygen atom, i.e., H H C: O H direct-sum Therefore, a purely statistical argument would suggest that the hydroxycarbene molecule HCOH is twice as likely as formaldehyde to be formed from H/sub 3/CO/sup +/ via dissociative recombination, a process generally considered to be very important in interstellar clouds. Theoretical studies show that, while HCOH has never been observed in the laboratory, it should nevertheless be a relatively stable molecule. Theoretical equilibrium structures for H/sub 3/CO/sup +/ and HCOH suggest that they may be observed at 63.5 and 68.4 GHz respectively.