On the Initiation of the Polymerization of Vinylchloride with Manganese(III) ‐acetyl‐acetonateThe initation reaction of the polymerization of vinyl chloride in dimethylformamide with manganese acetylacetonate is investigated. The reduction of the transition metal, the splitting of a ligand of the metal chelat and its incorporation into the polymer molecule is proved and the structure of the initiating radical is determined. The rate and efficiency of initiation is measured by the inhibition met