Monomeric and dimeric Al(iii) complexes for the production of polylactide

Dalton Trans. 2016 Sep 21;45(35):13846-52. doi: 10.1039/c6dt02861f. Epub 2016 Aug 11.

Abstract

A series of monometallic and bimetallic Al(iii) complexes with substituted naphthyl based Schiff base ligands have been prepared and characterised. When 1-aminonaphthalene based ligands were reacted with AlMe3 monometallic complexes were isolated, however, with 1,5 and 1,8-diaminonaphthalene based ligands bimetallic complexes were formed. In all cases 4-coordinate tetrahedral Al(iii) centres were observed in the solid state and in solution. There was little difference in rate of polymerisation of rac-lactide between the monometallic and bimetallic complexes based on 1,5-diaminonaphthalene. However, for the 1,8-diaminonaphthalene the complex was an order of magnitude faster than the monometallic and the analogous 1,5-system. Moreover, this complex was active at room temperature, which is rare for aluminium initiators, and PLA with a high degree (Pm = 0.82) of isotacticity was observed.

MeSH terms

  • Aluminum / chemistry*
  • Coordination Complexes / chemical synthesis*
  • Coordination Complexes / chemistry
  • Crystallography, X-Ray
  • Ligands
  • Molecular Structure
  • Naphthalenes / chemical synthesis*
  • Naphthalenes / chemistry
  • Polyesters / chemical synthesis*
  • Polyesters / chemistry
  • Polymerization
  • Schiff Bases / chemistry*
  • Stereoisomerism
  • Structure-Activity Relationship

Substances

  • Coordination Complexes
  • Ligands
  • Naphthalenes
  • Polyesters
  • Schiff Bases
  • poly(lactide)
  • Aluminum