alpha-diimine, diamine, and diphosphine iron catalysts for the controlled radical polymerization of styrene and acrylate monomers

Rachel K. O'Reilly, Michael P. Shaver, Vernon C. Gibson, Andrew J. P. White

Research output: Contribution to journalArticlepeer-review

Abstract

The synthesis and characterization of a family of iron complexes of the type (R)[NN]FeX2 (X = halide; (R)[NN] = RN=CH-CH=NR, R = alkyl, aryl) and their application as catalysts for the controlled polymerization of styrenyl and acrylate monomers is described. Polymerizations catalyzed by alkylimine iron complexes give rise to atom transfer radical polymerization (ATRP) of styrene and methyl methacrylate, while those catalyzed by arylimine iron complexes give rise to catalytic chain transfer polymerization. A study of the ketimine series, (R,Me)[N,N]FeCl2 (where (R,Me)[N,N] = RN=C(Me)-C(Me)=NR, R = Cy, Ph, DiPP), showed that electronic factors govern the mechanistic pathway. Controlled polymerizations were also observed for methyl acrylate and p-methoxy styrene monomers. Moderate control over the polymerization of 2-hydroxypropyl methacrylate was achieved in methanolic solution using methyl-alpha-bromophenylacetate as an initiator. The analogous diamine and diphosphine iron complexes, (Et2NCH2CH2NEt2)FeCl2 and (R2PCH2CH2PR2)FeCl2 (R = i-Pr, Ph, C6F5, C6H11, Et), were also prepared and screened for ATRP behavior. The phosphine complexes were found to be the most reducing in the series, followed by the amines and then the imines, but large peak-to-peak (Delta E-p) separations, indicative of poor reversibility, resulted in their poor performance as ATRP catalysts.

Original languageEnglish
Pages (from-to)7441-7452
Number of pages12
JournalMacromolecules
Volume40
Issue number21
DOIs
Publication statusPublished - 16 Oct 2007

Fingerprint

Dive into the research topics of 'alpha-diimine, diamine, and diphosphine iron catalysts for the controlled radical polymerization of styrene and acrylate monomers'. Together they form a unique fingerprint.

Cite this