ANALYSIS OF THE HYDRAZINE-FLUORINE FLAME - A-2(A')-X-2(A'') EMISSION-SPECTRUM OF HNF AND ITS RELATION TO OTHER HAB COMPOUNDS

The chemiluminescent reaction N2H4 + F2 is shown to be dominated by visible emission from NH* (A3Π-X3Σ-), HNF* (A2A′-X2A″) and vibrationally excited HF†(X1 Σ+). Possible mechanisms for formation of these species are discussed with reference to previous results from similar flame reactions. The A-X emission spectrum of HNF contains the heretofore unreported progression (0, 0, 0) → (0, υ2″, 0) to vibrational levels υ2″ = 0-3 of the X2A″ state. Each vibrational transition shows well resolved K-type subbands characteristic of a near symmetric rotor. A partial rotational analysis gives band origins and effective rotational constants for the first four vibrational levels of the ground state. The measured ground state vibrational constants are ω0 = 1441.1 ± 1.0 cm-1 with ω0χ0 = 10.9 ± 0.5 cm-1. The substantial differences in the A-X emission spectra of HNF and its isoelectronic analog HOO are discussed as they relate to bonding trends in HAB molecules. The concepts presented are extended to other HAB systems. © 1979.