Jump to main content
Jump to site search


Zirconium and hafnium complexes bearing pyrrolidine derived salalen-type {ONNO} ligands and their application for ring-opening polymerization of lactides

Author affiliations

Abstract

The reactions of pyrrolidine derived salalen-type {ONNO} ligands (S)-L1–3-H2 with 1 equiv. M(OiPr)4(HOiPr) (M = Zr or Hf) in diethyl ether yielded complexes [L1–3M(OiPr)2] (L = L1, M = Zr (1); L = L2, M = Zr (2), Hf (3); L = L3, M = Zr (4), Hf (5)). All of these complexes were well characterized by NMR spectroscopy, elemental analyses and single-crystal X-ray analysis in the case of complexes 1 and 3–5. X-ray structural determination revealed that these complexes were analogous mononuclear species and had a similar structure in which the metal centers were six-coordinated to two oxygen atoms and two nitrogen atoms of one ligand and two oxygen atoms of two isopropoxy groups. All of these complexes efficiently initialized the ring-opening polymerization of lactides to afford polymers with controlled molecular weight and narrow polydispersity. Furthermore, the ring-opening polymerization of rac-lactide catalyzed by complexes 1–5 afforded isotactic-enriched polymers in solution (Pm = 0.74–0.80) and under melt conditions (Pm = 0.63–0.72).

Graphical abstract: Zirconium and hafnium complexes bearing pyrrolidine derived salalen-type {ONNO} ligands and their application for ring-opening polymerization of lactides

Back to tab navigation

Supplementary files

Publication details

The article was received on 10 Jun 2017, accepted on 12 Jul 2017 and first published on 19 Jul 2017


Article type: Paper
DOI: 10.1039/C7DT02113E
Citation: Dalton Trans., 2017, Advance Article
  •   Request permissions

    Zirconium and hafnium complexes bearing pyrrolidine derived salalen-type {ONNO} ligands and their application for ring-opening polymerization of lactides

    Y. Duan, Z. Hu, B. Yang, F. Ding, W. Wang, Y. Huang and Y. Yang, Dalton Trans., 2017, Advance Article , DOI: 10.1039/C7DT02113E

Search articles by author

Spotlight

Advertisements