6533b826fe1ef96bd1284d56

RESEARCH PRODUCT

Spectroscopie des hexafluorures à nombre impair d'électrons

Vincent Boudon

subject

spectroscopy[PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph]Jahn-Teller effectreprésentations projectives[ PHYS.PHYS.PHYS-ATOM-PH ] Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph]spectroscopiecouplages rovibroniqueshexafluorures colorésprojective representationsrovibronic couplings[PHYS.PHYS.PHYS-ATOM-PH] Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph]effet Jahn-Tellerformalisme tensorieltensorial formalismcolored hexafluorides

description

From a theoretical point of view, a tensorial formalism adapted to the study of molecules or octahedral ions with a half-integer angular momentum has been developed for the first time. We have used here the method of projective representations, more consistent than that of double groups. A complete set of coupling coefficients and formulas, as well as the corresponding computing programs have been elaborated. This has firstly allowed to write a simple model describing the vibronic structure of colored hexafluorides. Then, somme applications of this formalism to the study of rovibronic couplings of XY6 molecules in a fourfold degenerate electronic state have been considered, especially concerning operators associated to dynamic Jahn-Teller effect. From an experimental point of view, we have considered IrF6, for which we have mastered the synthesis, purification and conservation processes. A first study at low resolution (absorption and Raman scattering) has been performed for this molecule. We have then set up two high resolution spectroscopic devices in the visible region (saturated absorption - tested with an iodine cell- and simple absorption with multiple pass). These especially use a dye laser. They should now allow the spectroscopy of the visible band of IrF6 in order to resolve for the first time its fine rotational structure.

https://tel.archives-ouvertes.fr/tel-00004609