Κρυσταλλογραφικός, φασματοσκοπικός (IR, 57Fe Moessbauer, EPR) και μαγνητικός χαρακτηρισμός πολυπυρηνικών συμπλόκων μεταλλοϊόντων μεταπτώσεως και λανθανίδων

Abstract

In this Thesis, the chalcogenated imidodiphosphinato ligands, R2P(E)NHP(E)R2, R = alkyl or aryl, Δ = O, S, Se, were synthesized, along with their complexes with Ni(II), Fe(II), Cu(II) and Co(II). The structural and spectroscopic properties of these compounds were investigated in detail. The [Ni{iPr2P(Se)NP(Se)iPr2}2] complex was crystallized in two isomer forms, namely tetrahedral and square planar. On the other hand, [Ni{Ph2P(Se)NPPh2}2] was crystallized in its trans square planar form. The [Ni{Ph2P(Se)NP(Se)Ph2}2] and [Ni{Ph2P(S)NP(S)Ph2}2] complexes were studied by cyclic voltammetry in the presence of CO, which affected the redox waves. The [Fe{iPr2P(Se)NP(Se)iPr2}2] and [Fe{iPr2P(S)NP(S)iPr2}2] complexes afforded crystals exhibiting isostructural tetrahedral geometries and were studied by Mössbauer spectroscopy. These Fe(II) complexes were shown to be rather air sensitive. The [Cu4{Ph2P(Se)NP(Se)Ph2}3]PF6 complex was shown to be a tetranuclear Cu(I) complex, with characteristic intermolecular Van der Waals attractions between Se atoms of neighboring molecules in the crystal. The [CuCl2{iPr2P(O)HNP(O)iPr2} complex is the first structurally characterized system bearing the iPr2P(O)HNP(O)iPr2 ligand. The latter was shown to be coordinated in its protonated form, which is unusual for this type of ligands. The [CoCl2{iPr2P(O)NHP(O)iPr2}] and [Co{iPr2P(O)ΗNP(O)iPr2}3][CoCl4] complexes were isolated in crystals containing three different complexes in their unit cell, namely [CοCl2{(iPr)2P(O)HNP(O)(iPr)2}], [Cο{(iPr)2P(O)HNP(O)(iPr)2}3]2+ and [CoCl4]2. Efforts to provide justifications of the observed structural preferences in all the above systems constitute a major part of this work. In addition, the following complexes were synthesized and studied by appropriate, in each case, spectroscopic methods, like ΙR, UV-Vis, NMR, EPR and Mössbauer spectroscopies: [Ni{Ph2P(S)NPPh2}2], [Fe{Ph2P(S)NP(S)iPr2}2], [Co{Ph2P(S)NP(S)iPr2}2], [Ru{iPr2P(Se)NP(Se)iPr2}3], [Ru{Ph2P(S)NP(S)iPr2}3], [Ru{Ph2P(Se)NP(Se)Ph2}3] and [Zn{Ph2P(S)NP(S)iPr2}2].