Dynamics of selected rovibronic B 3Π(0+) states of IF: Variation of the electronic transition moment with internuclear distance

Rovibronic levels of the IF B 3Π(0+) state have been selectively excited using a cw dye laser in a crossed-molecular-beam experiment in which IF molecules were synthesized in the X 1∑+ ground state. Einstein A coefficients have been obtained from the fluorescence spectra. RKR potentials, Franck–Condon factors, and r centroids have been calculated using recently determined molecular constants for the X and the B state. The r-centroid approximation was found to be valid for the B–X system of IF and the variation of the electronic transition moment with the internuclear distance was determined. Over a range of the internuclear distance, 1.9<r<2.4 Å, the electronic transition moment was found to increase by as much as a factor of 2.4.