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Home    Σύνθεση και χαρακτηρισμός συμπλόκων του κοβαλτίου με τεχνητά αμινοξέα και πολυ – αλκοόλες ως υποκαταστάτες  

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Identifier 000387782
Title Σύνθεση και χαρακτηρισμός συμπλόκων του κοβαλτίου με τεχνητά αμινοξέα και πολυ – αλκοόλες ως υποκαταστάτες
Alternative Title Synthesis and characterization of cobalt complexes with artificial amino acids and poly-alcohol ligands
Author Νικολαΐδου, Έλενα Μάριος
Thesis advisor Μηλιός, Κωνσταντίνος Ι.
Abstract In the present work we have investigated the employment of four new organic ligands, MeLH3 (2-(((3-hydroxynaphthalen-2-yl)methylene)amino)-2-methylpropane-1,3-diol), EtLH3 (2-ethyl-2-(((3-hydroxynaphthalen-2-yl)methylene)amino)propane-1,3-diol), LH4 (2-(hydroxymethyl)-2-(((3-hydroxynaphthalen-2-yl)methylene)amino)propane-1,3-diol), and BrLH3 (2-((5-bromo-2-hydroxybenzylidene)amino)-2-methylpropane-1,3-diol), in the presence of the artificial amino acids 2-amino-isobutyric acid, aibH, and 2-amino-butyric acid, abH, in Co(II/III) chemistry. In total, seven new cobalt complexes were isolated and characterized: [CoIII3(ΜeL)2(aib)3]∙2MeOH (1∙2MeOH), [CoIII2CoII(MeLH)2 (MeL)(aib)] (2), [CoIII3 (EtL) 2 (aib) 3]∙2.15MeOH (3∙2.15MeOH), [CoIIL’] (4), [CoIII2CoII (LH2)2 (LH)(aib)] (5), [CoIII3(EtL)2(ab)3] .2MeOH (6.2MeOH) [CoII5CoIII4 (Br-L’H) 4 (Br-L’) 4 (Cl) 2] .2.8MeOH.3.6EtOH.0.4H2O (7.2.8MeOH.3.6EtOH. 0.4H2O) More specifically, the reaction between MeLH3 with Co(OAc)2.4H2O and aibH in the presence of NEt3 in MeOH, gave complex [CoIII3(ΜeL)2(aib)3] .2MeOH (1.2MeOH), while the same reaction under solvothermal conditions yielded complex [CoIII2CoII(MeLH)2 (MeL)(aib)] (2). Switching to LH4 and upon reacting Co(OAc) 2.4H2O, LH4 and aibH, in the presence of NEt33 in MeCN we managed to isolate cluster [CoIII2CoII (LH2)2 (LH)(aib)] (5). On the other hand, switching to EtLH3 and upon reacting Co(OAc) 2.4H2O, EtLH3 and aibH, in the presence of NEt3 in MeOH we managed to isolate cluster [CoIII3 (EtL) 2 (aib) 3].2.15MeOH (3.2.15MeOH), while upon employment of the artificial amino acid 2-amino-butyric acid, abH, we characterized cluster[CoIII3(EtL)2(ab)3].2MeOH (6.2MeOH). Moreover, complex [CoL’] (4) comprises a mononuclear Co(II) complex which is formed by the EtLΗ3 “breaking” in 2-OH-naphthaldehyde and aminodiol, followed by the Schiff base formation upon reacting with ethylenediamine molecule in order to form the new L’ ligand. Finally, the reaction between CoCl2.4H2O, aibH and Br-L’H3 (=2-((5-bromo-2-hydroxybenzylidene)amino)-2-methylpropane-1,3-diol) in EtOH in the presence of NEt3 under solvothermal conditions formed the nonanuclear mixed-valent cluster [CoII5CoIII4 (Br-L’H) 4 (Br-L’) 4 (Cl) 2] .2.8MeOH.3.6EtOH.0.4H2O (7.2.8MeOH.3.6EtOH. 0.4H2O) following recrystallization from MeOH. The complexes were characterized by single-crystal X-ray crystallography, elemental analysis and dc magnetic susceptibility measurements under an applied dc field of 1000 G. Clusters 1, 2, 3, 5 and 6 were studied by means of positive and negative ion Sonic - Spray Ionization Mass Spectrometry (SSI-MS), establishing the structural integrity of the metallic species in MeOH. Furthermore, the magnetic properties of the nonanuclear cluster 7.EtOH were investigated under dc magnetic field revealing the presence of dominant ferromagnetic interactions within the metallic complex, leading to an S = 9/2 ground-state.
Language Greek
Subject Artificial amino-acids
Cobalt
Organic ligands
Poly-alcohols
Schiff bases
Βάσεις Schiff
Κοβάλτιο
Οργανικοί υποκαταστάτες
Πολυαλκοόλες
Issue date 2014-11-21
Collection   School/Department--School of Sciences and Engineering--Department of Chemistry--Post-graduate theses
  Type of Work--Post-graduate theses
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