SYNTHESIS AND EXPLORATORY PHOTOPHYSICAL INVESTIGATION OF DONOR BRIDGEACCEPTOR SYSTEMS DERIVED FROM N-SUBSTITUTED 4-PIPERIDONES

We report a two-step synthesis for N-aryl- and N-alkyl-substituted 4-p iperidones, in which the N substituent can easily be varied. A number of intramolecular donor-acceptor systems was synthesized from these pi peridones by conversion of the carbonyl functionality. The influence o f the N-aryl donor on the electronic absorption and fluorescence spect ra was investigated systematically. It was concluded that some systems can be used as efficient fluorescent probes with a high sensitivity f or solvent polarity.