Excitation induced emission color change based on Eu(III)-Zn(II)-containing polymer complex

Abstract

A novel polymer P-1 is prepared by the reaction of the monomer 5,5'-divinyl-2,2'-bipyridine and Salen-Zn(II) via Heck cross coupling. Interestingly, P-1 can further incorporate with Eu(TTA)(3)·2H(2)O to generate copolymer P-2 with two different metal centers. P-2 exhibits exceptional dual emissive properties which can be tuned by excitation wavelength. For example, an orange fluorescence can be obtained when P-2 is excited at 430 nm, whereas a red emission with a huge Stoke shift of 57 nm is observed when it is excited at 345 nm. The high wavelength emission can be attributed to Eu(III) ((5)D(0)→(7)F(2) ), which is lit by an effective photoinduced energy transfer process between P-1 and the Eu(TTA)(3) complex. The properties of P-2 have led to a better understanding of the energy transfer process between P-1 and Eu(TTA)(3) moieties.