A study of variation of electronic transition moment of the B-X system of I2from its laser-excited fluorescence spectrum

Abstract

Fluorescence in the B 3 Pi (0+u)-X 1 Sigma g+ system of I2 excited with 5145 AA radiation of an argon ion laser was recorded photoelectrically in the region 5200-8500 AA on a SPEX 0.85 m double monochromator. Using the measured intensities of P(17) rotational lines of thirty-eight ( nu '=43, nu ) bands and the Franck-Condon factors based on the recent molecular data of the B and X states, the variation of the square of the electron transition moment, mod M(R) mod 2, with R centroid in the range R=2.65-3.09 AA was studied. It was noticed that the electronic transition strength has a maximum value at R=2.83 AA and is represented by the relation mod M(R) mod 2=constant(-500.358+377.125R-38.483R2-25.429 R3+4.9831R4). Present results are discussed in relation to those obtained from earlier studies.