| Abstrakt: |
A coaxial ion beam/laser beam spectrometer has been used to measure 52 transitions in the fundamental rotation–vibration band of the X 2Π electronic state of the molecular anion 15NH-. Infrared P, Q, and R-branch transitions (2950–3320 cm-1) are excited by a color center laser beam to autodetaching states, and the fast neutral NH is detected. The uncertainty (1 SD) is 0.01 cm-1. The spectroscopic constants returned by a least-squares fit to an effective Hamiltonian have been combined with our previous results on 14NH- to yield equilibrium vibrational constants ωe and ωexe for both isotopes (cm-1): ωe (14NH-)=3191.5±2.1, ωexe (14NH-)=85.6±1.9, ωe (15NH-)=3184.4±2.1, and ωexe (15NH-)=85.2±1.9. There is good agreement with the theoretical calculation for 14NH- by Manz, Zilch, Rosmus, and Werner: ωe=3179, ωexe=89. The electron affinity has been measured: EA(15NH)=0.3761±0.0025 eV. [ABSTRACT FROM AUTHOR] |
