ΔHf: 28.0 kcal/mol, REF: M. W. Chase, C. A. Davies, J. R. Downey, D. R. Frurip, R. A. McDonald, A. N. Syverud, JANAF Thermochemical Tables, Third Edition, J. Phys. Chem. Ref. Data 14, Suppl. 1 (1985). I.P.: 10.1 eV, REF: H. M. Rosenstock, K. Draxl, B. W. Steiner, J. T. Herron, "Energetics of Gaseous Ions," J. Phys. Ref. Data, 6 Suppl. 1 (1977).