Electronic Spectrum and Dissociation Energy of Fluorine

The continuous absorption spectrum of molecular fluorine and the Raman displacement for the 0→1 vibrational transition have been used to compute the potential energy curve for the repulsive 1Πu state dissociating to two normal fluorine atoms. This curve is consistent with a value of 37.1±0.85 kcal mole—1 for the dissociation energy of the ground state. A weak absorption, attributed, on the grounds of location and intensity, to 3Π0+u←1Σg+, has been shown to occur in the long wavelength region of the main absorption and a segment of the potential energy curve for 3Π0+u has been deduced. Absorption curves, calculated from the potential energy curves and the ground-state anharmonic eigenfunctions, fit the observed data satisfactorily.