Microwave spectroscopic studies of hydrogen exchange, isomerization and hydrogenation of unsaturated hydrocarbons on the stoichiometric electron donor–acceptor complexes of phthalocyanine with alkali metals

Abstract

Hydrogen exchange, isomerization and hydrogenation of olefins, such as C₂H₄, C₃H₆ and C₄H₈, was studied over the stoichiometric electron donor–acceptor (EDA) complexes of various phthalocyanines with alkali metals (Li, Na, K). The mass and microwave spectroscopic techniques have been shown to be effective for determining not only the deuterium content but also its distribution in the [²H₁] and [²H₂]-species of the reactant and product molecules. It was accordingly concluded that these three reactions proceed through the same reaction intermediate; the half-hydrogenated state of the olefins, and that the rate-determining step is the process where the π-coordinated olefin becomes the σ-coordinated half-hydrogenated state. The chemisorbed state of the olefins and the mechanisms of these reactions were correlated with the electron configuration of the EDA complexes.