Photodissociation dynamics of NH3: Rovibronic absorption analysis of the A–X transition and nuclear spin polarization in the NH2 (X 2B1) product

The ÖX̃ electronic spectra of jet-cooled NH3, obtained by probing the LIF of the NH2 (X̃ 2B1) fragments, are presented. The homogeneous linewidths for the v′2 =0 and v2 =1 vibrational bands are estimated as 32±2 and 30±2 cm−1, respectively. A partial analysis of the excitation energy dependence of the rotational energy distribution in NH2 (X̃ 2B1) is also examined. The results clearly show that the photodissociation of the à state NH3 proceeds via a near planar structure in a nuclear spin conserved manner.