Homopiperazine and piperazine complexes of Zr(IV) and Hf(IV) and their application to the ring-opening polymerisation of lactide

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

In this paper we describe the preparation and characterisation, by single-crystal X-ray diffraction, of twelve ZrIV/HfIV complexes based on piperazine or homopiperazine salan ligands. With the piperazine ligands, a mixture of species was observed and various solid-state structures were isolated. However, with homopiperazine salan ligands, 1:1 ligand-tometal complexes were observed both in solution and in the solid state. Interestingly, for the homopiperazine complexes the isopropoxide ligands are trans to one another in the solid state, most likely because of the rigid nature of the homopiperazine backbone. All homopiperazine Hf(IV) and Zr(IV) complexes were tested for the ring-opening polymerisation (ROP) of rac-lactide. The complexes are active and produce polylactide with narrow polydispersity indices. The kinetics and living characteristics of the polymerisation have also been investigated.
Original languageEnglish
Pages (from-to)4596-4602
Number of pages7
JournalEuropean Journal of Inorganic Chemistry
Volume2011
Issue number29
DOIs
Publication statusPublished - Oct 2011

Fingerprint

Ring opening polymerization
Ligands
Polydispersity
Polymerization
dilactide
piperazine
Single crystals
X ray diffraction
Kinetics

Keywords

  • sustainable chemistry
  • hafnium
  • ring-opening polymerization
  • titanium
  • zirconium

Cite this

@article{e7cb0f2f81504255abc5cf7c51d2f0b6,
title = "Homopiperazine and piperazine complexes of Zr(IV) and Hf(IV) and their application to the ring-opening polymerisation of lactide",
abstract = "In this paper we describe the preparation and characterisation, by single-crystal X-ray diffraction, of twelve ZrIV/HfIV complexes based on piperazine or homopiperazine salan ligands. With the piperazine ligands, a mixture of species was observed and various solid-state structures were isolated. However, with homopiperazine salan ligands, 1:1 ligand-tometal complexes were observed both in solution and in the solid state. Interestingly, for the homopiperazine complexes the isopropoxide ligands are trans to one another in the solid state, most likely because of the rigid nature of the homopiperazine backbone. All homopiperazine Hf(IV) and Zr(IV) complexes were tested for the ring-opening polymerisation (ROP) of rac-lactide. The complexes are active and produce polylactide with narrow polydispersity indices. The kinetics and living characteristics of the polymerisation have also been investigated.",
keywords = "sustainable chemistry, hafnium, ring-opening polymerization, titanium, zirconium",
author = "Hancock, {Stuart L} and Mahon, {Mary F} and Gabriele Kociok-Kohn and Jones, {Matthew D}",
year = "2011",
month = "10",
doi = "10.1002/ejic.201100589",
language = "English",
volume = "2011",
pages = "4596--4602",
journal = "European Journal of Inorganic Chemistry",
issn = "1434-1948",
publisher = "Wiley-VCH Verlag",
number = "29",

}

TY - JOUR

T1 - Homopiperazine and piperazine complexes of Zr(IV) and Hf(IV) and their application to the ring-opening polymerisation of lactide

AU - Hancock, Stuart L

AU - Mahon, Mary F

AU - Kociok-Kohn, Gabriele

AU - Jones, Matthew D

PY - 2011/10

Y1 - 2011/10

N2 - In this paper we describe the preparation and characterisation, by single-crystal X-ray diffraction, of twelve ZrIV/HfIV complexes based on piperazine or homopiperazine salan ligands. With the piperazine ligands, a mixture of species was observed and various solid-state structures were isolated. However, with homopiperazine salan ligands, 1:1 ligand-tometal complexes were observed both in solution and in the solid state. Interestingly, for the homopiperazine complexes the isopropoxide ligands are trans to one another in the solid state, most likely because of the rigid nature of the homopiperazine backbone. All homopiperazine Hf(IV) and Zr(IV) complexes were tested for the ring-opening polymerisation (ROP) of rac-lactide. The complexes are active and produce polylactide with narrow polydispersity indices. The kinetics and living characteristics of the polymerisation have also been investigated.

AB - In this paper we describe the preparation and characterisation, by single-crystal X-ray diffraction, of twelve ZrIV/HfIV complexes based on piperazine or homopiperazine salan ligands. With the piperazine ligands, a mixture of species was observed and various solid-state structures were isolated. However, with homopiperazine salan ligands, 1:1 ligand-tometal complexes were observed both in solution and in the solid state. Interestingly, for the homopiperazine complexes the isopropoxide ligands are trans to one another in the solid state, most likely because of the rigid nature of the homopiperazine backbone. All homopiperazine Hf(IV) and Zr(IV) complexes were tested for the ring-opening polymerisation (ROP) of rac-lactide. The complexes are active and produce polylactide with narrow polydispersity indices. The kinetics and living characteristics of the polymerisation have also been investigated.

KW - sustainable chemistry

KW - hafnium

KW - ring-opening polymerization

KW - titanium

KW - zirconium

UR - http://www.scopus.com/inward/record.url?scp=80053969699&partnerID=8YFLogxK

U2 - 10.1002/ejic.201100589

DO - 10.1002/ejic.201100589

M3 - Article

VL - 2011

SP - 4596

EP - 4602

JO - European Journal of Inorganic Chemistry

JF - European Journal of Inorganic Chemistry

SN - 1434-1948

IS - 29

ER -