Etude théorique de la structure électronique des composés boranes, leurs dérivés et les composés organométalliques apparentés

Abstract

In this work, we focused on improving the description, by theoretical methods DFT type of transition metal complexes, their stability and change of electronic and structural characteristics. For complex Hpca presented in the second chapter we found that all the complex 18- MVE, in The C2 and Ci symmetries give structures iso-energy, regardless of the method used, the decrease and the increase and decrease of dihedral angle for reduced and oxidized species for each metal category, calculated bond lengths are close disponobles to those for experimental values and the MO distances (H2O) calculated are longer than those of MO (Hapca) and the loss of two water molecules to the species [Co] - and [Ni] neutral. In the third chapter, the metal retains its shape regardless of the nature and position of ligand surrounding them. Calculated bond lengths have a small gap of experimental. OM of Diagrams are a layer-closed configuration with small large energy differences by type of metal coordinated look to de-hydro -semicarbazone that behaves as a bidentate ligand coordinated by the deprotonated phenolic oxygen and oxygen carboxylic group acétyle.Pour the electronic transitions observed and theoretical diagrams tires are MLCT character for the complex [1] - while are MLCT , ILCT types for [2] and the type MMCT for [3] complex. In the case of the study devoted to complexes fourth chapter, we have shown that the complex geometry of stability of Cu (II) and related and depends heavily on the nature of these ligands and can vary significantly depending on the nature of directly bonded atoms the resort center, we found that the ligand with azide N3- and the substituent (OH) stabilizes the complex, in our case the complex [3] and [3] * are more stable that in accordance with the principle of maximum hardness which establishes that the hardness (HOMO-LUMO gap) is maximal for the isomer most stable and that the generated character and degenerate copper coordinating these ligands.