Is There a Minimum Polarizability Principle in Chemical Reactions?

For complete fragmentations of the type A m B n ...→ m A + n B + ... the change of the dipole polarizabilty Δα ≡ ∑ i ν i α i and its cube-root Δα CR ≡ ∑ i ν i α i 1/3 as well as the atomization energy D at are calculated from literature data (ν i is the stoichiometric coefficient). We have taken into account a large number of molecules containing the atoms H, C, N, O, S, P, F, Cl, Br, and I as well as the metals Fe and Os. The ranges of D at and ∑ i ν i α i covered by the fragmentations are between 150 and 15 000 kJ mol -1 and −6 and 170 × 10 -41 C 2 m 2 J -1, respectively. In most cases Δα > 0 is observed, whereas we always find Δα CR > 0. Additionally, we observe a linear relationship D at = A μ + B μ ∑ i ν i α i μ between the atomization energy D at and the sum of the dipole-polarizabilities of all chemical species taking part in the fragmentation. The linear relation is obtained for μ = 1 and 1 / 3 . Our observation implies that the most stable isomer has the lowest polarizability and that in chemical reactions the most stable species (reactants or products) have the lowest sum of α 1/3 .