Sinteza in strukturne značilnosti novih luminiscentnih lantanoidnih kompleksov z izbranimi N-donorskimi ligandi : doktorska disertacija

slovenian

doktorska dela

2015

Univerza v Mariboru, Fakulteta za kemijo in kemijsko tehnologijo

The presented work extends and deepens general knowledge in the field of chemical systematics of coordination compounds with central atoms regarding f - block elements in periodic table. The investigation describes the syntheses, and characterisation of new lanthanide(III) coordination compounds with biologically important nitrogen donor ligands such as nicotinic (NIC) and dipicolinic acid (Pydc). It has been shown that these precursors are very useful for forming coordination compounds with metals, because of its coordination mode. Having successfully synthesised and characterised lanthanide complexes with simple N-donor ligands, we further used the synthesis principle to synthesise lanthanide metal complexes with certain mixed ligands. The first examples of coordination compounds with dipicolinc acid and 2-aminobenzothiazole (ABT) were synthesised according to the Cambridge Structural Database (CSD). This research area has so far been less well studied due to differences reactivities of individual organic ligands. The recent research on synthesis and structure of metal complexes enabled us to make partial predictions regarding the connectivity of crystalline lattices based on the molecular structure of the small building blocks used in their assembly. The realization of this research work gave us new compounds, but also contributed to better understanding of the formation of coordination compounds. Syntheses of the compounds were followed by their characterization by elemental and thermogravimetric analysis, IR and fluorescence spectroscopy, and magnetic measurements. In the case of successful single-crystal preparation we determined the crystal-structure using X-ray diffractometer with CCD detector in collaboration with Faculty of Chemistry and Chemical Tehnology University of Ljubljana. We prepared seven new lanthanide(III) coordination compounds with pyridine ligands. Additional molecules of solvent (water) are also present in some structures. The research was also directed toward searching of new syntheses, in this way we isolated various di-nuclear complexes such as: Yb2(NIC)6(H2O)4, Gd2(NIC)6(H2O)4, and Nd2(NIC)6(H2O)4 (only the structural details of this compound were already known), mononuclear complexes: Na3Ho(Pydc)3 14H2O, and Na3Dy(Pydc)3 14H2O, and also mononuclear complexes with mixed ligands: (ABT)3Eu(Pydc)3 5H2O, (ABT)3Tb(Pydc)3 5H2O, (ABT)Cu(Pydc)(PydcH) 3H2O. The comparison between the selected structural parameters enables easier understanding of the results obtained by spectroscopic or other methods. The majority of the results in this thesis were published in international scientific journals.

07.08.2023