R. Ponec et al., SIMILARITY APPROACH TO CHEMICAL-REACTIVITY - THEORETICAL JUSTIFICATION OF THE HAMMOND POSTULATE, Journal of mathematical chemistry, 19(3-4), 1996, pp. 265-270
The recently proposed similarity index was applied to the quantitative
justification of the empirical Hammond postulate for a series of sele
cted pericyclic reactions. In keeping with the expectations of the pos
tulate the transition states were shown to be reactant-like for exothe
rmic and product-like for endothermic reactions.