Fluorescence quenching effect of metal ions for α,α′-diamine containing conjugated polymers in solid films

Abstract

The fluorescence quenching effect of the conjugated polymers P1 and P2 (the molecular recognitions are twisted 2,2′-bipyridine (bpy) and planar 1,10-phenanthrolin (phen), respectively) films upon the addition of metal ions has been studied. And the results showed that P2 exhibited stronger fluorescence quenching ability upon the addition of both transition metal ions and main group metal ions compared with that of P1. The 20° twist angle between the two consecutive pyridine rings of bpy unit in the P1 main chain is the reason for the weaker fluorescence quenching ability compared with P2, in which the planar phen unit can chelate with metal ions relatively freely without the conformational transition. So P2 is a kind of material with better properties for solid film devices, such as sensors for metal ions recognition.