Di- and trivalent rare earth complexes stabilized by sterically demanding aminopyridinato ligands as initiators in ring-opening polymerization reactions of epsilon-caprolactone

Sophie M. Guillaume (1, 2) , Michèle Schappacher (1) , Natalie M. Scott (3) , Rhett Kempe (3)

1 LCPO - Laboratoire de Chimie des polymères organiques
2 Team 1 LCPO : Polymerization Catalyses & Engineering
3 Lehrstuhl für Anorganische Chemie II

Salt elimination protocols using Ap*K {Ap*H = (2,6-diisopropyl-phenyl)[6-(2,4,6-triisopropyl-phenyl)-pyridin-2-y1]-amine} lead to the rare earth aminopyridinato complex [Ap*LuCl2(thf)(2)], 4. Results of X-ray crystal structure analyses of 4 and the corresponding single THF coordinated dimer are discussed. Ring-opening polymerization of epsilon-caprolactone initiated by complexes [Ap*LaBr2(thf)(3)], 2, [Ap*YbI(thf)(2)](2), 3 or 4 in the presence of NaBH4 allows the preparation, in a short reaction time, of alpha,omega-dihydroxytelechelic polymers with high molar mass ((M) over bar (n) up to 50,000) and moderate molar mass distributions (1.3 < <(M)over bar>(w)/(M) over bar (n) < 1.6). (C) 2007 Wiley Periodicals, Inc.

Mots clés: aminopyridinato complex [Ap*LuCl2(thf)(2)]; X-ray crystal structure analyses; rare earth; ring-opening polymerization of epsilon-caprolactone; synthesis; aminopyridinato ligands; borohydride; catalysts; polyesters

Domaines: Polymères

Sophie M. Guillaume, Michèle Schappacher, Natalie M. Scott, Rhett Kempe. Di- and trivalent rare earth complexes stabilized by sterically demanding aminopyridinato ligands as initiators in ring-opening polymerization reactions of epsilon-caprolactone. Journal of Polymer Science Part A: Polymer Chemistry, 2007, 45 (16), pp.3611-3619. ⟨10.1002/pola.22110⟩. ⟨hal-00284769⟩