Dokument

Summary:
This Thesis is dedicated to the synthesis and investigation of the rare-earth metal complexes with two particular types of chelating monoanionic ligand systems: • ortho-deprotonated N,N-dimethyl-benzylamines (dmba)– • cyclopentadienyl-phosphazenes (CpPN)– The first ligand system is presented by a series of side-chain modified (dmba)– ligands that have been used to study the influence of present or absent benzylic protons on the stability of homoleptic rare-earth metal tris-aryl complexes. Discussion of their synthesis, thermal stability and crystal structures composes Chapter II. The second and novel ligand system is presented by a series of CpPN-ligands with different substituents on P- and N-atoms and at the Cp-ring. A discussion of their syntheses, prototropic equilibria and molecular structures is presented in Chapter III. Cyclopentadienyl-phosphoranes are the intermediates in the CpPN ligand synthesis. Thus a new highly crowded cyclopentadienyl-phosphane skeleton, some mechanistic aspects of its formation, its reactivity toward oxidants and some examples of coordination chemistry of this new ligand are reported in Chapter IV. Finally, a detailed study on the synthesis and analysis of the coordination modes of the rare-earth metal CpPN-complexes with different ligands and metals is presented in Chapter V. An additional contribution to this work is the development of a simple and versatile synthesis of anhydrous etherates [LnBr3(solv)n] that are very promising precursors for the coordination and organometallic chemistry of the rare-earth metals. Combined with some general considerations on rare-earth metal chemistry this contribution is discussed in Chapter I of this Thesis.

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