Selfassembly of lanthanide based polymetallic architectures for the design of new luminescent devices.

The assembly of sophisticated high nuclearity coordination complexes with relatively simple ligands allows the combination of their nanoscopic size with the magnetic or optical properties of the metals leading to interesting new materials. The incorporation of lanthanides (III) in such highly organised polymetallic complexes is of great interest in supramolecular chemistry, in view of their interesting magnetic and luminescent properties. Indeed, the creation of polymetallic architectures is crucial for the design of lanthanide-based devices such as light converters, logic gates, biomedical probes or MRI contrast agents. In spite of this, the assembly of lanthanide based supramolecular architectures has lagged behind that of other systems due to the difficulty in controlling the coordination environment of these ions which display high and variable coordination numbers with little stereochemical preferences.

The subject of the proposed thesis lies within the scope of a new project developed in our laboratory on luminescent nanomaterials and is part of the CEA Nanotechnology program “chemistry for nanoelectronics”.

The project has the objective of investigating the molecular parameters leading to the self-assembly of large lanthanides based polymetallic architectures of predefined structure. In particular the attention will be focused on the synthesis of highly luminescent compounds of nanometric size and based on the use of multidentate asymmetric ligands derived from pyridine, oxazoline or pyrazole. The assembly of enantiopure lanthanide complexes will also be investigated.

The subject proposed involves the organic synthesis of new ligands and the study of their coordination chemistry with lanthanide ions using different techniques. The structure will be determined by X-ray diffraction studies, NMR, and electrospray studies. The photophysical properties will be investigated in detail, in solution and in the solid states. The functionnalisation of different surfaces (gold and silica) and the photophysical properties of the resulting materials will also be investigated.

References

1. Bretonniere, Y.; Mazzanti, M.; Pecaut, J.; Olmstead, M. M., J. Am. Chem. Soc. 2002, 124, 9012-9013.

2. Chen, X. Y.; Bretonniere, Y.; Pecaut, J.; Imbert, D.; Bunzli, J. C.; Mazzanti, M., Inorg. Chem. 2007, 46, 625-637.

3. Marchal, C.; Filinchuk, Y.; Imbert, D.; Bunzli, J. C. G.; Mazzanti, M., Inorg. Chem. 2007, 46, 6242-6244.

Web: http://www-drfmc.cea.fr/Pisp/51/marinella.mazzanti

Potential candidates should send a CV and a recommendation letter by E-mail to Marinella Mazzanti before end february 2008. The chosen candidate will be submitted to evaluation after formal application for a CEA fellowship (one of the most prestigious French research Institutions) and will receive a formal offer in July 2008.

Email:

The thesis lasts exactly three years with an approximate salary of 1600 euros.