title: Conformationally flexible dimeric salphen complexes for bifunctional catalysis.
abstract: Appropriate modification of the salphen ligand allows an easy modular design of flexibly linked dimeric salphen species and their complexes, which can act as bifunctional catalysts. A series of chromium salphen systems including monomeric compound and dimers with different spacer lengths were tested for their catalytic performance in β-butyrolactone polymerization and CO(2)/propylene oxide copolymerization toward biodegradable materials. The results clearly show an enhancement in activity upon dimerization, thus underlining the role of bifunctional catalysis in the studied processes and extending the possible strategies for improvement of catalysts in these reactions.
authors.affiliation: Wacker Lehrstuhl für Makromolekulare Chemie, Technische Universität München, Lichtenbergstrasse 4, D-85748 Garching, Germany.
authors.forename: Sergei I
authors.initials: SI
authors.lastname: Vagin
authors.forename: Robert
authors.initials: R
authors.lastname: Reichardt
authors.forename: Stephan
authors.initials: S
authors.lastname: Klaus
authors.forename: Bernhard
authors.initials: B
authors.lastname: Rieger