graduate studies
  UKSW College
  of Science

Edyta Kołodziejczyk
"Crystal engineering of coordination complexes of a group 13 metaloorganic elements"


     The main aim of my Ph. D. work was to investigate the crystal structures of group 13 organometallic complexes and to determine the factors controlling this structure. The complexes of aluminium, gallium and indium derived from amino-alcohols and complexes of aluminium derived from bifunctional ligand EDBP: 2,2'-ethylidenebis(4,6-di-tert-butylphenol) were used as model systems. X-ray single-crystal diffraction was used as the experimental technique. The data obtained from X-ray diffraction were used to determine the crystal structures of thirteen compounds. With this information in hand, the role of different intermolecular forces in aggregation and self-assembly of molecules was investigated as well. The role of steric factors connected with the nature of ligands and the coordination center in the arrangement of the complexes derived from aminoalcohols was analyzed. It is shown that upon controlling of the coordination center and the chelate ligand structure e.g. chain size, various molecular aggregations may be constructed.
     The crystal structure analysis of the complexes studied demonstrate how hydrogen bonding can effectively compete with metal ligand coordination preferences in determining the molecular and crystal structure and how conformational changes in a ligand and increased steric bulk on the carbon atom adjacent to amine group can impart on a network morphology and molecular aggregations.
     In this work the analysis of the steric and electronic factors on the structure of aluminium complexes stabilized by bifunctional aryloxide ligand EDBP was performed. Our investigations show that electronic factors are more important than steric factors in the case studied. Differences in geometrical parameters my be due to the changed electronic environment of the aluminium. In the case when the solvent molecules were present in the crystal lattice there was also analyzed the role of weak C-H...p interactions. The aryloxide complexes of aluminium were used as model systems for this study of the heterocyclic monomers polymerization mechanism.



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