Photodissociation Dynamics of Formic Acid at 206 nm

The photodissociation dynamics of formic acid (HCOOH) at 206 nm have been investigated from rotationally resolved laser induced fluorescence spectra of OH (Π) fragments produced exclusively in the ground state. From the spectra, the rotational energy of the fragments was measured to be 820 ± 50 cm−1. The translational energy released in the products, which is 87% of the total available energy of the system, was also measured from analyses of the Doppler profiles. Joining these data with quantum chemical molecular orbital calculations, we have concluded that the dissociation should take place along the S1 surface with an exit channel barrier and also that the energy partitioning is determined at the exit channel.