E-T and near-resonant E-V energy transfer in the quenching of the 1.0 and 2.3 μm electronically excited states of PuF6 by H2 and D2.

The quenching and energy transfer of electronically excited PuF6 by H2 and D2 have been measured using laser-induced fluorescence (LIF) from both the 1.0 and 2.3 μm emitting states of PuF6. Linear Stern–Volmer plots of the single exponential decay data give quenching rate constants (all in units of cm3 molecule-1 s-1) for D2 of (3.7±1.7)×10-15 and (8.7±0.3)×10-16 for the 1.0 and and 2.3 μm states, respectively, and a H2 quenching rate constant of (4.8±0.3)×10-14 for the 1 μm LIF. The 2.3 μm LIF in H2 is not a single exponential decay but a rapid decay followed by an anomalously long tail, which implies almost resonant E⇄V energy transfer and storage. Kinetic modeling yields the following new rate constants: PuF6*+H2→PuF6+H≠2, k=(2.05±0.30)×10-14; H2≠+PuF6→H2+PuF6*, k=(3.1±0.5)×10-14; PuF6*+H2→PuF6+H2, k=(3.1±2.0)×10-15; H2≠+PuF6→H2+PuF6, k=(3.1±3.0)×10-15; where PuF6* is the 2.3 μm emitting electronically excited state of PuF6 and H2≠ is vibrationally excited H2 in the v=1 state. [ABSTRACT FROM AUTHOR]