ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
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+HN3 reaction has confirmed that this reaction proceeds to form HNF+N2, as well as the well-known HF+N3 products. Laser fluorescence excitation scans were taken for a number of HNF and DNF A˜ 2A'(0,v'2,0)–X˜ 2A‘(0,0,0) bands. For DNF, excitation of the A˜ (0,2,1) and (0,3,1) levels were also detected. A partial rotational analysis of the DNF bands was carried out. With the derived A rotational constants and previously determined HNF rotational constants, it was possible to derive ground and excited state vibrationally averaged geometries. The K structure of the bands was observed to become simpler with increasing v2, reflecting the reduction in the highest K' levels observable by fluorescence excitation. Decay lifetimes for a variety of HNF and DNF A˜ 2A' excited levels were determined. It was found that the decay rate, scaled approximately by the ν3 factor, increases abruptly at an energy of 23 800±500 cm−1 above 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.462436
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