The Mechanism of the Action of Organometallic Catalysts

Abstract

Abstract Kinetic investigations of the polyreaction of isoprene with organolithium compounds as initiators in n‐heptane as solvent indicate the following sequence of reactions: 1. formation of an adduct between a monomeric form of the organolithium compound and the isoprene and 2. reaction of this adduct with an associated form of the organolithium compound with insertion of the isoprene. The adduct formation is considered to be due to chemisorption, and proof of such chemisorption of a monomer (ethylene) is also demonstrated for a homogeneous Ziegler‐type catalyst. All the reactions can be formulated in the form of cyclic structures with electron‐deficient character. Postulation of such ring structures explains the surprising values obtained for the frequency factors and equilibrium constants.