Efficient long-range collisional energy transfer between the E0(g)(+)(3P2) and D0(u)(+)(3P2) ion-pair states of I2, induced by H2O, observed using high-resolution Fourier transform emission spectroscopy.

Using high-resolution Fourier transform emission techniques, we have resolved rotational structure in the D0(u)(+)((3)P(2)) → X0(g)(+) emission following collisional transfer from the E0(g)(+)((3)P(2)) state in I(2). The P:R branch ratios in the E0(g)(+)((3)P(2)) → D0(u)(+)((3)P(2)) transfer are found to vary enormously with v(E) and v(D). We show that the observed intensities are all consistent with the transfer being dominated by long-range, near-resonant collisions with residual H(2)O. Unequal P:R branch ratios in the E0(g)(+)((3)P(2)) → A1(u) emission have been shown to result from mixing of the E0(g)(+)((3)P(2)) and β1(g)((3)P(2)) states via Ω-uncoupling.