LUMINESCENCE OF THE FLEXIBLE DYE MOLECULE JULOLIDINEMALONONITRILE IN POLYMER MATRICES AT PRESSURES ABOVE 40 KBAR

We study the luminescence efficiency of julolidinemalononitrile (JDMN) as a function of pressure in a series of vinyl polymers, PVAs, PVCl, PS, PVP and P1VN which exhibit increasing polarizability in the order listed. This molecule has both a planar and twisted excited state. Only the former emits luminescence. we concentrate on the behavior at pressures above 40 kbar. A decrease in intensity of emission is found with pressure which is larger, the larger the polarizability of the medium. This decrease results from increased stabilization of the polar twisted state with pressure in the more polarizable media.