Original Title:
Δομικές, φασματοσκοπικές και μαγνητικές ιδιότητες συμπλόκων των στοιχείων mn,fe,co,ni,cu,zn με χηλικούς ιμιδοδιφωσφινικούς υποκαταστάτες
Summary:
This thesis is focused on mixed-chalcogen derivatives of the imidodiphosphinic
ligand (OPPh2)(EPPh2)NH (E=S, Se) as well as on the dioxo analog (OPPh2)2NH and
the complexes that are obtained with Mn(II), Fe(III), Co(II), Ni(II), Cu(I) and
Zn(II) ions.
The synthesis and structural characterization, by X-ray crystallography, of the
tetrahedral [M{(OPPh2)(SePPh2)N}2] (M=Co, Ni, Zn), [Zn{(OPPh2)(SPPh2)N}2], the
tris-chelate octahedral [Fe{(OPPh2)(EPPh2)N}3] (E=S, Se), the binuclear
[Co2{(OPPh2)2N}4] and the trinuclear of Cu(I) : [Cu3{(OPPh2)(SePPh2)N}3]
complexes, has been accomplished by metathetical reactions of deprotonated
ligand K[(OPPh2)(EPPh2)N] with metal salts. The variety of theses geometries is
reinforced by the structural transformation of tetrahedral to octahedral
geometries of Ni(II) complexes upon recrystallization from coordination
solvents, such as dmf or thf. Thus, the pseudo-octahedral
[Co{(OPPh2)(SPPh2)N}2dmf2], [Ni{(OPPh2)(EPPh2)N}2sol2] (E=S, Se; sol=dmf, thf)
complexes, as well as the Mn(II) octahedral compounds
[Mn{(OPPh2)(EPPh2)N}2thf2] (E=S, Se) were prepared and structurally
characterized by X-ray crystallography.
The appropriate, for each case, spectroscopic method (IR, UV-Vis, NMR, EPR), in
combination with magnetization studies are employed in order to elucidate
electronic properties of the systems. Focusing on the octahedral Ni(II)
complexes, the high frequency and field EPR technique afforded valuable
information about the zero-field splitting D, E parameters and the g factor
components. Those results are compared with the magnetic susceptibility studies
in an effort to establish the corresponding magnetostructural correlations.
Keywords:
imidodiphosphinic ligands, transition metals, solvent coordination, crystal structures, electron paramagnetic resonance
