BIAN‐Fe(η6‐C6H6): Synthesis, characterization, and l‐lactide polymerization. Issue 17 (23rd June 2017)

• Record Type: Journal Article
• Authors: Brown, Lauren A.; Wekesa, Francis S.; Unruh, Daniel K.; Findlater, Michael; Long, Brian K.
• Is Part Of: Journal of polymer science. Volume 55:Issue 17(2017)
• Page Start: 2824
• Page End: 2830
• Publication Date: 2017-06-23
• Subjects: catalysis -- initiator -- iron -- l‐lactide -- polymerization; 547
• DOI: 10.1002/pola.28688
• Languages: English
• ISSNs: 0887-624X

Abstract

ABSTRACT: The α‐diimine‐ligated Fe‐complex, BIAN‐Fe(C6 H6 ), was synthesized and evaluated for the polymerization ofl ‐lactide. Characterization ofBIAN‐Fe(C6 H6 ) reveals that it is redox non‐innocent and suggests that it is an Fe(I) species bearing a radical‐anionic ligand. We will demonstrate thatBIAN‐Fe(C6 H6 ) is active for the ring‐opening polymerization ofl ‐ lactide, and that polymer is produced with, or without, the use of an added external initiator. Interestingly, very high molecular weight polymers are produced in the absence of external initiator whereas polymer molecular weights that agree with theoretical calculations are produced in the presence of external initiator. To the best of our knowledge, BIAN‐Fe(C6 H6 ) is the first Fe‐based α‐diimine catalyst reported to be active for the polymerization ofl ‐ lactide. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2017, 55, 2824–2830 Abstract : Catalysts bearing redox non‐innocent ligands have found a multitude of applications in both small molecule and polymerization catalysis. This paper describes a unique Fe‐based catalyst bearing an α‐diimine ligand that is highly active for the ring opening polymerization ofl ‐Lactide. This catalyst produces very high molecular weight polymer in the absence of added initiator, whereas addition of externally added initiator leads to molecular weights that decrease inversely as a function of added initiator.