What makes efficient circularly polarised luminescence in the condensed phase: aggregation-induced circular dichroism and light emission

• DOI: 10.1039/c2sc20382k
• Publication Date: 2012-06-13T11:31:58Z
• Authors: Jianzhao Liu; Huimin Su; Luming Meng; Yihua Zhao; Chunmei Deng; Jason C. Y. Ng; Ping Lu; Mahtab Faisal; Jacky W. Y. Lam; Xuhui Huang; Hongkai Wu; Kam Sing Wong; Ben Zhong Tang
• Keywords: Circularly polarised luminescence; Aggregation-induced emission; Circular dichroism; Luminogenic silole; 01 natural sciences; Chiral sugar moieties; 0104 chemical sciences

In this contribution, we conceptually present a new avenue to construction of molecular functional materials with high performance circularly polarised luminescence (CPL) in the condensed phase. A molecule (1) containing luminogenic silole and chiral sugar moieties was synthesized thoroughly characterized. solution 1, no circular dichroism (CD) fluorescence emission are observed, but upon aggregation, both CD simultaneously turned on, showing aggregation-induced (AICD) (AIE) effects. The AICD effect is supported by fact that molecules readily assemble into right-handed helical nanoribbons superhelical ropes when aggregated. AIE boosts quantum efficiency (ΦF) 136 fold (ΦF, ∼0.6% versus ∼81.3% solid state), which surmounts serious limitations aggregation-caused quenching encountered conventional luminescent materials. Time-resolved study theoretical calculation from first principles conclude restriction low-frequency intramolecular motions responsible for effect. assemblies 1 prefer emit light display large CPL dissymmetry factors (gem), whose absolute values range 0.08–0.32 two orders magnitude higher than those commonly reported organic We demonstrate time use Teflon-based microfluidic technique fabrication fluorescent pattern. This shows highest gem −0.32 possibly due enhanced assembling order confined microchannel environment. preserved after more half year storage under ambient conditions, revealing excellent spectral stability. Computational simulation performed interpret how aggregates interact each other at level. Our designed represents desired material generating efficient state, current best results among conjugated systems terms efficiency, factor,