STUDY OF THE PROPAGATION CENTER IN THE ANIONIC-POLYMERIZATION OF LACTAMS .2. MODEL STUDY OF THE INTERACTION BETWEEN AN ACTIVATED MONOMER AND N-ACYLLACTAM IN DIMETHYL-SULFOXIDE

Interaction of potassium 3,3-dimethyl-2-piperidone with 1-benzoyl-3,3- dimethyl-2-piperidone in DMSO as a model of the complex propagation ce ntre in the anionic polymerization of lactams has been studied by H-1 and C-13 NMR, infrared spectroscopy, and, for the Li counterion, by MN DO calculations. The reactants were found to form a loose complex whic h can emerge in various geometries sharing the equivalence and relativ e motional freedom of both lactam moieties. Types of internal motions in the complex are suggested and their implications for the detailed i dea of the propagation mechanism are discussed.