Recent studies on appearance energy and hot reaction zone in solid-state reactions in metallocenes and their β-cyclodextrin inclusion compounds

Striking contrasts were observed in the hot atom chemical retention-recoil energy relation between metallocenes and their β-cyclodextrin inclusion compounds. Energy dependence curves of the parent yields in ferrocene and ruthenocene dramatically dropped by the inclusion. However, the curve in osmocene did not change remarkably. Surprisingly, the parent yield was represented by one curve for ferrocene, ruthenocene and osmocene with inclusion. The independence on the chemical character was explained by considering that a larger reaction zone in pure metallocene was restricted by inclusion, and a hot atom reaction occurred in a unimolecular manner in the cyclodextrin cavity which led to the independence on elemental characters. Normalized appearance energy was estimated for the diagnosis of the processes in concern. Isotope effects in hot atom chemistry in ruthenocene-ferrocene mixtures were found for (γ, n) reactions for the first time. ((orig.))