Matrix-isolation study of the reaction of H atoms with NO

Studies of the reaction with NO in an argon or a nitrogen matrix at 4° or 14°K of H and D atoms produced either photolytically or in a microwave discharge have confirmed the previous identification of the ground-state NO stretching fundamental of HNO and of DNO but have dictated a reassignment of the deformation fundamental of these two species. An absorption at 1153 cm−1 has been assigned as the deformation fundamental of DNO, and evidence is presented suggesting that the deformation fundamental of HNO lies very close to 1500 cm−1. The assignment of an absorption at 2717 cm−1 as the NH stretching fundamental of HNO and of an absorption at 2043 cm−1 as the corresponding fundamental of DNO is consistent with the previous report of an exceptionally long NH bond for ground-state HNO. Detailed isotopic studies support this revised vibrational assignment, which is shown to be consistent with previous gas-phase studies. The force constants and thermodynamic properties of ground-state HNO derived from the matrix data are presented.