Bonding in FSSF3: Breakdown in Bond Length-Strength Correlations and Implications for SF2 Dimerization

The product of SF2 dimerization is an unusual molecule with many unexpected properties. For instance, there are four nonequivalent SF bond lengths, and they are not inversely correlated with their respective bond dissociation energies. Further, the minimum energy pathway to dissociation into two SF2 molecules does not involve breaking the longest or weakest SF bond. In this paper, we provide compelling explanations for both of these unusual observations by analyzing the generalized valence bond (GVB) wave function for FSSF3.