doktorska disertacija
Nuša Hojnik (Author), Matjaž Kristl (Mentor), Mihael Drofenik (Co-mentor)

Abstract

Namen doktorskega dela je bila razširitev in poglobitev znanja s področja kemijske sistematike koordinacijskih spojin s centralnimi atomi elementov f - bloka periodnega sistema. V doktorskem delu smo obravnavali sintezo in karakterizacijo novih koordinacijskih spojin lantanoidov z biološko pomembnimi N donorskimi ligandi, saj se je izkazalo, da so ti prekurzorji zelo uporabni za tvorbo koordinacijskih spojin s kovinami, saj lahko njihova koordinacija poteka na različne načine. Kot ligande smo uporabili nikotinsko kislino (NIC) in dipikolinsko kislino (Pydc). Raziskave smo razširili še na področje sintez koordinacijskih spojin z mešanimi ligandi. Sintetizirali smo prve primere spojin, ki hkrati vsebujejo z dipikolinsko kislino in 2 aminobenzotiazol (ABT), za kakršne v kristalografski podatkovni zbirki (CSD) še ni obstajal zapis. To področje je do sedaj slabše raziskano zaradi razlik v reaktivnosti posameznih ligandov. Zaenkrat naše spojine niso vsebovale 2 aminobenzotiazol kot ligand ampak kot kation. Zasledovanje sintez in analiza struktur koordinacijskih spojin z organskimi ligandi nam je omogočilo delno napovedovanje povezovanja gradnikov v kristalno mrežo že na osnovi poznavanja molekulske zgradbe samih gradnikov. Realizacija raziskovalnega dela je vodila do priprave novih spojin in tudi prispevala k boljšemu razumevanju nastanka koordinacijskih spojin. Uspešni pripravi monokristalov je sledila skrbna analiza strukture, kjer smo uporabili difraktometer s CCD detektorjem za monokristale v sodelovanju s FKKT Univerze v Ljubljani. Opravili smo še infrardečo spektroskopijio, termogravimetrično in elementarno analizo, magnetne meritve, v nekaterih primerih pa tudi fluorescenčno spektroskopijo. Pripravili smo skupaj sedem novih spojin z različnimi razmerji med centralnim atomom in dušikovim ligandom. V nekaterih primerih je v strukturi koordinacijske molekule vezana tudi voda. Raziskave so potekale v smeri iskanja novih sintez, na ta način smo izolirali različne dvojedrne komplekse kot so, [Yb2(NIC)6(H2O)4] in [Gd2(NIC)6(H2O)4] ter prav tako določili strukturo koordinacijske spojine [Nd2(NIC)6(H2O)4], za katero so bili v literaturi objavljeni samo parametri osnovne celice, enojedrne kompleksne spojine z Na3[Ho(Pydc)3] 14H2O in Na3[Dy(Pydc)3] 14H2O ter različne enojedrne kompleksne spojine z ABT in Pydc (ABT)3[Eu(Pydc)3] 5H2O, (ABT)3[Tb(Pydc)3] 5H2O, (ABT)[Cu(Pydc)(PydcH)] 3H2O. S primerjavo z izbranimi strukturnimi parametri lahko lažje razumemo dobljene rezultate, ki nam jih nudijo spektroskopske ali druge metode. Večina rezultatov je objavljenih v mednarodnih znanstvenih revijah.

Keywords

lantanoidni kompleksi;rentgenska strukturna analiza;luminiscenca;magnetne meritve;vodikove vezi;

Data

Language: Slovenian
Year of publishing:
Typology: 2.08 - Doctoral Dissertation
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [N. Hojnik]
UDC: 52-628:542.057(043.3)
COBISS: 18725398 Link will open in a new window
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Other data

Secondary language: English
Secondary title: SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF NOVEL LUMINISCENT LANTHANIDE COMPLEXES WITH N−DONOR LIGANDS
Secondary abstract: 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: Na3[Ho(Pydc)3] 14H2O, and Na3[Dy(Pydc)3] 14H2O, and also mononuclear complexes with mixed ligands: (ABT)3[Eu(Pydc)3] 5H2O, (ABT)3[Tb(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.
Secondary keywords: lanthanides complexes;x.ray structure determination;luminiscent properties;magnetic properties;hydrogen bonds;
URN: URN:SI:UM:
Type (COBISS): Dissertation
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: [XIV f.], 118 str.
ID: 8752466