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Dissertation: „Lithium, magnesium, zinc and vanadium complexes supported by diaminebis(aryloxido) ligands – synthesis, characterization and reactivity.” mgr Ew Kober Supervisor: dr hab. Zofia A. Janas, prof. UWr. The main goal of the presented research was the synthesis, structural characterization and reactivity of lithium, magnesium, zinc and vanadium complexes supported by diaminebis(phenolate) ligands. Three types of tetradentate, dianionic [O,N,N,O] ligands: tripodal, linear and imidazolidine-bridged have been used to realize the scientific project. Thirty two new metal complexes including seven lithium, three magnesium, two zinc and twenty vanadium were prepared. The solution structure of all complexes were examined and the solid state structures were determined for twenty of them. Tripodal diaminebis(phenolate) ligand generates tetra- and hexalithium complexes which reveal the cube, cube with oxygen bridged on two opposite edges, hexagonal prisms and flexed ladder-like structures, respectively. Magnesium and zinc complexes bearing tripodal ligands have dimeric nature while the linear ligands generate trimeric magnesium and dimeric zinc complexes. Two series of monomeric oxovanadium(V) complexes were obtained and fully characterized. Complexes possess Cs-symmetry, octahedral geometry around the vanadium centre and a variety of structural isomers. Tripodal ligands generate in solution trans-1 and trans-2 complexes but in the solid state only trans-1 isomer was isolated. Achiral linear ligands adopt a cis–α configuration around octahedral vanadium center and form a racemic mixture of enantiomers with Δ and Λ helicity. Imidazolidenebis(phenol) gives monoand dinuclear okso-vanadium complexes depending on the reaction stoichiometry. A mixture of mono- and dimeric oxo-vanadium(IV) complexes supported on the linear ligands were obtained via the reduction of oxo-vanadium(V) compounds by 1-methyl-1phenylhydrazine (NH2NMePh). In protolytic solvents, complexes are unstable and disproportionate to vanadium(III) and oxo-vanadium(V) complexes. Lithium complexes, in contrast to the magnesium and zinc compounds, were found to efficiently initiate the ring opening polymerization (ROP) of L-lactide in the presence of benzyl alcohol at the room temperature yielding isotactic polymers (PLLAs) with relatively narrow polydispersity indexes. The oxidation of styrene and cyclohexene, catalyzed by oxovanadium(IV) and (V) complexes was carried out using tert-butylhydroperoxide as the external oxidant. Styrene oxide and cyclohexene oxide were obtained with high conversion and selectivity.