HIGH-PRESSURE STUDIES OF THE ORGANIC TRIPLET

High pressure up to 50 kbar generated in a diamond anvil cell has been applied to the investigation of organic molecules in their phosphores cent triplet state. Experimental techniques include specifically adapt ed optically detected magnetic resonance (ODMR) and optical spectrosco py. This paper reviews some of the high points of our results. On the microscopic scale there is no isotropic compression. Pressure enhances the interaction of a chromophore with its neighbours in a few specifi c modes according to crystalline packing. These interactions may shift the energy levels of the chromophore, or enhance the dynamical proces ses in the crystal. A variety of pressure-induced effects may be ratio nalized on this basis.