ΔHf: -18.0 kcal/mol, REF: D. D. Wagman, W. H. Evans, V. B. Parker, T. Hawlow, S. M. Bailey, R. H. Schumm, Natl. Bur. Stand. (U.S.), Tech. Note, No 270-3 (1968) and "Errata in NBS Technical Note 270-8" (1981). Dipole: 3.8 Debye, REF: K. P. Huber, G. Herzberg, "Molecular Spectra and Molecular Structure," IV. "Constants for Diatomic Molecules," Van Nostrand, Reinhold, New York, (1979). I.P.: 9.7 eV, REF: R. D. Levin, S. G. Lias, "Ionization Potentials and Appearance Potential Measurements," 1971-1981, Natl. Stand. Ref. Data Ser., Natl. Bur. Stand. 71, (1982), Cat. No. C13.48:71.