Characterization of a shallow-bound 0(g)(+) valence state of I-2 using emission from the D 0(u)(+) (P-3(2)) and F ' 0(u)(+) (D-1(2)) ion-pair states populated by amplified spontaneous emission

A range of vibrational levels of the D 0(u) (+)(P-3(2)) and F' 0(u) +(D-1(2)) ion-pair states of I-2 is shown to be easily generated by amplified spontaneous emission (ASE) from their more accessible partners, E 0(g) (+)(P-3(2)) and f' 0(g) +(D-1(2)), in sufficient concentration for dispersed fluorescence studies of the D 0(u) +(P-3(2)) -> 0(g) (+)(bb) and F' 0(u) +(D-1(2)) -> 0(g) +(bb) transitions to be carried out. T-0 (J = 49) of this shallow-bound 0(g) +( bb) valence state is unambiguously determined and an improved R-e value of 3.952 +/- 0.005 angstrom is obtained from optimizing the fit of the intensities of the vibrational progressions in the 0(g) (+)( bb) state, and T-e is found to be 27311.3 +/- 2 cm(-1), leading to D-e = 442.0 +/- 2 cm(-1).