TiCp2Cl-catalyzed living radical polymerization of styrene initiated by oxirane radical ring opening

Alexandru D Asandei; Isaac W Moran

doi:10.1021/ja046936f

TiCp2Cl-catalyzed living radical polymerization of styrene initiated by oxirane radical ring opening

J Am Chem Soc. 2004 Dec 15;126(49):15932-3. doi: 10.1021/ja046936f.

Authors

Alexandru D Asandei¹, Isaac W Moran

Affiliation

¹ Institute of Materials Science, Polymer Program, and Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, USA. asandei@ims.uconn.edu

PMID: 15584705
DOI: 10.1021/ja046936f

Abstract

Epoxides and paramagnetic early transition metal complexes are introduced as two new classes of initiators and catalysts, respectively, for living radical polymerizations. Thus, Ti(III)Cp2Cl synthesized in situ from the reduction of TiCp2Cl2 with Zn catalyzes the radical ring opening of oxiranes to initiate the radical polymerization of styrene. A linear dependence of molecular weight on conversion, low polydispersity, and reinitiation of the polymerization in the presence of fresh monomer indicates that the polymerization is living and that it most likely occurs by the reversible endcapping of the macroradical with Ti(III). Moreover, epoxides provide convenient access to alcohol chain ends, suitable for further transformations.