Energy disposal in the photodissociation of Co(CO)(3)NO near 225 nm

The photodissociation of Co(CO)(3)NO was studied near 225 nm. Apparent two- photon dissociation of the parent compound produces Co* in a number of exci ted states that emit in the range of 340-360 nm. Both quartet and doublet s tates of Co* are observed, implying the existence of spin-conserving and no nspin-conserving dissociation channels. Assignment of the Co* emission is u sed to calculate an upper limit for the average metal-ligand bond dissociat ion energy of 36.2-38.6 kcal/mol with no spin-conservation restrictions and 41.2-43.9 kcal/mol with spin-conservation restrictions. The Co* emission i ntensities are used to determine the relative populations of particular J a nd spin states and to demonstrate that J states within a particular LS conf iguration are statistically populated. The NO photoproduct was detected by fluorescence excitation spectroscopy. The NO appears to follow dual Boltzma nn statistics with rotational temperatures of 580 +/- 70 K for E-rot < 500 cm(-1) and 2800 +/- 300 K for E-rot > 500 cm(-1).