ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
NI in argon and in argon/10% N2 matrices has been excited into b 1Σ+, v'=0–4 with a pulsed tunable dye laser. The regular line structure in the fluorescence excitation and emission spectra in pure argon matrices is attributed to a local phonon progression of 15 cm−1, both in the X 3Σ− and b 1Σ+ states. "Hot'' local phonon lines, which originate in the thermally populated levels n'=1 and 2 of the local phonon mode at elevated temperatures, have been identified. The matrix lifetime of the vibrationally relaxed b state, which does not relax via the a state in pure argon, extrapolates to a radiative lifetime of 15 μs in vacuo, in satisfactory agreement with a recent gas phase determination. The a state of NI, which emits at 1185 and 1173 nm, could be populated via the b state only in mixed matrices of argon and N2. The lifetime in these matrices is 20.5±2 ms, which extrapolates to a gas phase radiative lifetime of approximately 38 ms. The b state of NI is completely quenched in pure nitrogen matrices, but emission from the a state is still detected with a lifetime of 4.6±0.5 ms. On the basis of these results recently reported a-state lifetimes of NCl and NBr in the ms to sub-ms range appear unreasonably low.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.450321
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