Popis: |
A series of monomeric coordination compounds containing zinc(II) chloride or zinc(II) bromide and the 1,2-diamine ligands TMEDA, TEEDA, (R,R)-TMCDA, (R,R)-TECDA and cis-TMCDA have been synthesised and structurally characterised using X-ray diffraction analysis. All but one complex could be successfully used as initiators for the solvent-free ring-opening polymerisation of d,l -lactide. In particular, the polylactide (PLA) prepared with compounds containing (R,R)-TECDA is obtainable in high yields with molecular weights suitable for industrial applications. Thus a class of stable, easy to synthesise and efficient PLA catalysts with neutral ligands is introduced. |