Gas-phase and solution-phase polymerization of epoxides by Cr(salen) complexes: evidence for a dinuclear cationic mechanism.
The gas-phase reactions of a series of mass-selected mononuclear and dinuclear Cr(salen) complexes with propylene oxide suggest that the enhanced reactivity of the dinuclear complexes in gas-phase and in solution may derive from a dicationic mechanism in which the alkoxide chain is mu(2)-coordinated to two Lewis acidic metal centers. The double coordination is proposed to suppress backbiting, and hence chain-transfer in the gas-phase homopolymerization of epoxides.
Schön
Eva
E
Laboratorium fur Organische Chemie, HCI G209/ETH-Zurich, Wolfgang-Pauli-Strasse 10, CH-8093 Zurich, Switzerland.
Zhang
Xiangyang
X
Zhou
Zhiping
Z
Chisholm
Malcolm H
MH
Chen
Peter
P