Etude des propriétés magnétiques des agrégats de platine et d'argent

Abstract

Our work deals with the study of the molecular magnetism. The calculations, mainly made by means of the functional theory of the density DFT, allowed to determine the electronic structures for systems of more or less important sizes with are clusters of platinum or aggregates of silver. These methods showed their efficiency in the calculations of the molecular structures, the chemical shift , magnetic moments, and the UV-VISIBLE specters in TD-DFT. For the complexes mono and tri-nuclear based with platinum studied, the comparison between the parameters of chemical shift of 195 Pt calculated NMR and those experimental is generally completely satisfactory. The formalism Pauli reproducing better the experiment results than the formalism Zora; the variation of the paramagnetic contribution , the term spin orbit or contact of Fermi are responsible for the value of the chemical shift of compounds. For the neutral pure aggregates Agn ( n=2-9) in gas phase, the most stable structures were characterized and their structural, energy , magnetic properties as well as their specters of UV-VISIBLE absorption is calculated by CAM-B3LYP and LC-M06L, with a type QZVP basis.