The ultra-violet absorption spectra of some gaseous alkali-metal halides and the dissociation energy of fluorine

Abstract

Measurements of the fluctuation bands in the ultra-violet absorption spectra of NaF, KF, RbF, RbCl, RbBr, RbI, CsF, CsCl, CsBr and CsI are reported, and upper limits for the dissociation energies of the twelve K, Rb and Cs halides are deduced. Thermochemical information about these molecules is considered, and a value for the dissociation energy of fluorine, D$_{\text{F}_{2}}$ = 37$\cdot $6 $\pm $ 3$\cdot $5 kcal or 157$\cdot $3 $\pm $ 14$\cdot $6 kJ (298 degrees K), is derived.