Circularly polarized luminescence and tuning chromaticity of Eu(III)-grafting chiral polymer based on variable position of the substitution.

The novel chiral conjugated polymers P-1 and P-3 are prepared from the monomers S-M-2 and S-M-3 with (R,R)-1,2-aminocyclohexane (M-1) via a nucleophilic addition-elimination reaction, respectively. The Eu(III)-grafting chiral polymers P-2 and P-4 could be obtained by direct coordination reaction of Eu(TTA)3 ·2H2 O with P-1 and P-3, respectively. Photoexcitation of P-2 produces pink color emission as a result of the combination of partial blue self-emission chromophore of P-1 along with the red color from the Eu(TTA)3 moiety, whereas P-4 shows the exclusively red color emission from the Eu(III) ((5) D0 →(7) F2 ) transition due to almost complete excitation energy transfer from the macromolecular chain to the Eu(TTA)3 moiety. The choice substitution of phenyl derivative of the polymer plays a crucial role on the efficient energy transfer from the polymer chain to Eu(III) ion center. Meanwhile, the glum value of the dissymmetry factor of circularly polarized luminescence (CPL) for the (5) D0 →(7) F2 transition of Eu(III) for P-4 reaches as high as +0.0207, whereas P-2 exhibits the largest glum value about +0.0464 centered at 434 nm.