Spin-state relaxation dynamics in iron(II) complexes: solvent on the activation and reaction and volumes for the 1A ⇌5T interconversion

Abstract

Activation and reaction volumes are reported for the interconversion of the ¹A and ⁵T isomers of Fe^II complexes in several solvents; the reaction volume ΔV° and the activation volume ΔV₁₅^‡ are solvent-dependent but ΔV₅₁^‡ for the ⁵T →¹A crossover is markedly negative and virtually solvent-dependent and a transition state geometry intermediate between the ¹A and ⁵T isomers is implied.