THE RELATION BETWEEN THE STRUCTURE OF NITROBENZENE DERIVATIVES AND FLUORESCENCE QUENCHING EFFICIENCY TO THE POLY(2,5-DIPENTYLOXY-para-PHENYLENE ETHYNYLENE)

The poly(2,5-dipentyloxy-para-phenylene ethynylene)(P) was synthesized by Pd-catalyzed Sonogashira coupling reaction.Due to causing energy transfer between the nitrobenzene's quenchers and the polymer chains through the charge-transfer interaction,the fluorescence quenched properties of P varied obviously with the para-substituting group's structure in the nitrobenzene derivatives.The fluorescence quenching efficiency of quenchers improved with increasing of electron repulsion capability of the para-substituting group.The fluorescence quenching efficiency increased nonlinearly with the concentration of the quenchers and had,however,no relation with the quenching time.