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 wellhyphen;known HF+N3products. Laser fluorescence excitation scans were taken for a number of HNF and DNFAtilde;thinsp;2Arsquo;(0,vrsquo;2,0)ndash;Xtilde;thinsp;2Alsquo;(0,0,0) bands. For DNF, excitation of theAtilde; (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 highestKrsquo;levels observable by fluorescence excitation. Decay lifetimes for a variety of HNF and DNFAtilde;thinsp;2Arsquo;excited levels were determined. It was found that the decay rate, scaled approximately by the ngr;3factor, increases abruptly at an energy of 23thinsp;800plusmn;500 cmminus;1above the HNF(Xtilde;thinsp;2Alsquo;) zerohyphen;point level. This threshold is tentatively assigned to the onset of a predissociation channel. The ground and excited states of HNF form a Rennerndash;Teller pair, whose energies become degenerate at linear geometries. The excited state dynamics of HNF (DNF) is compared with the dynamics of the wellhyphen;studied Rennerndash;Teller molecules HCO and HNO.
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