QUANTUM-CHEMICAL STUDY OF SOME SYSTEMS MO DELING THE BEHAVIOR OF ALUMOPORPHYRINE INITIATORS OF POLYMERIZATION

Mechanism of interaction between aluminum chloride derivative of porph yne, which is model-analog of alumoporphyrine initiators, with ethylen e oxide, propiolactone, and valerolactone is studied. Data obtained us ing the method of modified neglect of diatomic overlap (MNDO) evident to much greater reactivity of Al-Cl anionic bond of the initiator comp ared to Al-N bonds. Values of energy characteristics obtained for the system containing ethylene oxide point to even greater reactivity of A l-O bond formed in the stage of initiation. Calculated energy paramete rs of the system aluminum-chlorporphyne-lactone agree with experimenta lly observed inactivity of chlorine-containing alumoporphyrine initiat or with respect to valerolactone and its reactivity with respect to pr opiolactone. To explain this difference, study of the interaction of p ropiolactone and valerolactone with Cl- and CH3O- ions was undertaken additionally.