Laser fluorescence excitation has been employed to detect HNF and its isotopomer DNF in the F/HN3(DN3) system. The observation of this molecule in the F+HN3reaction has confirmed that this reaction proceeds to form HNF+N2, as well as the well‐known HF+N3products. Laser fluorescence excitation scans were taken for a number of HNF and DNFA˜ 2A’(0,v’2,0)–X˜ 2A‘(0,0,0) bands. For DNF, excitation of theA˜ (0,2,1) and (0,3,1) levels were also detected. A partial rotational analysis of the DNF bands was carried out. With the derivedArotational constants and previously determined HNF rotational constants, it was possible to derive ground and excited state vibrationally averaged geometries. TheKstructure of the bands was observed to become simpler with increasingv2, reflecting the reduction in the highestK’levels observable by fluorescence excitation. Decay lifetimes for a variety of HNF and DNFA˜ 2A’excited levels were determined. It was found that the decay rate, scaled approximately by the ngr;3factor, increases abruptly at an energy of 23 800±500 cm−1above the HNF(X˜ 2A‘) zero‐point level. This threshold is tentatively assigned to the onset of a predissociation channel. The ground and excited states of HNF form a Renner–Teller pair, whose energies become degenerate at linear geometries. The excited state dynamics of HNF (DNF) is compared with the dynamics of the well‐studied Renner–Teller molecules HCO and HNO.
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