E0g+→A1u and E0g+→B″1u laser-induced fluorescence in molecular iodine recorded by Fourier-transform spectroscopy

Efficient long-range collisional energy transfer between the E g+(3P2) and D u+(3P2) ion-pair states of I2, induced by H2O, observed using high-resolution Fourier transform emission spectroscopy

“…It can be seen that the R:Q:P branch ratios are not 1:2:1 as expected, with the P branch (J = 31 → 32 emission line) being significantly more intense than the R branch. This phenomenon can be observed in the spectra shown by Inard et al 2 but was not commented on by the authors. In all of the spectra that we recorded, the trend increases with J; two examples are shown in Figs.…”

“…2 It could be clearly seen that while the P:Q:R branch ratios in the direct E0 g + ( 3 P 2 ) → C1 u emission were as expected, those in the E0 g + ( 3 P 2 ) → A1 u emission were not, but this observation was not commented on by the authors. In this case, we will propose that the imbalance is due to -uncoupling between the E0 g + ( 3 P 2 ) and β1 g ( 3 P 2 ) states, first reported in absorption by Perrot et al 4 Potential energy curves of all of the relevant states 2, 5-10 are shown in Fig.…”

“…However, such data are available in a much earlier study, 2 in which Fourier transform (FT) detection was used. Rotational structure was resolved in D0 u + ( 3 P 2 ) → X0 g + emission that was also observed following collisional transfer from the E0 g + ( 3 P 2 ) state which had been selectively excited by optical-optical double resonance (OODR).…”

“…These spectra were recorded with the specific aim of obtaining molecular constants for the C1 u valence state (called B 1 u in Ref. 2 and some earlier studies but relabelled to be consistent with the notation used for the other halogens). As it was not possible to record any new spectra with this experimental arrangement, we were restricted to re-examining the original data in the light of our recent study.…”

The influence of amplified spontaneous emission in collisional energy transfer studies exemplified by to transfer in I2

“…In another OODR study [16] in which two continuous-wave dye lasers were used, (v = 1) of the E0 þ g ð 3 P 2 Þ state was excited and transfer induced by collisions with I 2 in the ground state observed. The simulations of the D0 þ u ð 3 P 2 Þ !…”