Pyrolytic production of Se (³P) from carbon diselenide. I. Equilibrium

Thermodynamic characteristics of the dissociation of carbon diselenide are examined. Results of a shock‐tube study of CSe 2 pyrolysis are combined with previously unreported photoionization spectroscopy data on CSe 2 and with a critical examination of the available literature on Se( g ), Se 2 ( g ), CSe( g ), CSe 2 ( g ), and CSe 2 ( t ). Based on the best currently available information, recommendations are made for the values of enthalpies, entropies, heat capacities, and derived functions. In particular, the most likely value for Δ H 0 (CSe 2 ( g ) → CSe( g ) + Se( g , 3 P )) is +83 kcal/mol, and for K p at 2000°K it is 0.018 atm.