Description succincte
(Anglais)
|
The objective of the present project is to model on computers the molecular properties of Cyanides of the transition-metals (TM), forming Prussian blue-(PB) type structures because of their ability to form magnetic materials with magnetic ordering transitions at room and even higher temperatures (Tc). Recently, the transparent and magnetic Mn4[Mn(CN)6]2.75.20.3 H2O has been prepared (Decurtins et al, Bern, Tc=35K). The origin of the magnetism in this material very probably originates from MnII and MnIII pairs, linked by CN- groups. Thus, a deeper understanding of the underlying mechanisms is needed by our colleagues working experimentally. In this project we intend to carry out DFT and difference-dedicated CI ab-initio calculations on mononuclear and homo- and hetero-binuclear cyanide complexes with Mn and other TM of the 3d-series in order to describe accurately the observed magnetic properties.
|
Partenaires et organisations internationales
(Anglais)
|
AT, BE, BG, HR, FI, MK, FR, DE, EL, HU, IL, IT, LT, NL, NO, PL, SK, ES, SE, CH, UK
|
Résumé des résultats (Abstract)
(Anglais)
|
Electronic structures and electronic properties of transition metal complexes including both 3d and 4f metals(lanthanoids) have been studies using a new methodology developed in our group. For complexes of this type, possessing a mostly ionic transition metal-ligand bond ligand field theory is the method of choice because it allows to correlate electronic structure and chemical bonding with their spectroscopic and magnetic behaviour. We proposed a new DFT based ligand field model which consists in using DFT data to deduce ligand field parameters. The approach allows not only to interpret but also to predict electronic properties such as electronic spectra and magnetic exchange coupling.
|
