Advances in helicene derivatives with circularly polarized luminescence

Abstract

This review summarizes the recent research progress of helicenes and their derivatives with circularly polarized luminescence properties.

The Progress and Perspective of Organic Molecules With Switchable Circularly Polarized Luminescence

“…Although there are a number of known strategies to design CPL active materials and a large library of material structures are available (Pop et al, 2019;Sang et al, 2019;Zhao W. L. et al, 2019;Ouyang and Liu, 2020), it is as yet unrealistic to predict related CPL activities for any given structure. Neither the handedness nor the degree of asymmetry can be confidently or accurately predicted from the material composition or the components (e.g., enantiomer excess value).…”

Thermally activated delayed fluorescence material-sensitized helicene enantiomer-based OLEDs: a new strategy for improving the efficiency of circularly polarized electroluminescence

“…Their unique helical structures and specific photoelectric properties make them become one of the most attractive chiral fluorescent molecules in recent years [40][41][42][43][44][45]. Although helicene enantiomers with circularly polarized photoluminescence (CPPL) of high g lum values have attracted increasing interest and become one of the hottest topics in CPL materials [46], the CPEL of helicene enantiomers lag significantly behind. Moreover, helicenes usually suffer from difficult synthesis, easy racemization, and low quantum yield.…”

Chiral Diketopyrrolopyrrole-Helicene Polymer With Efficient Red Circularly Polarized Luminescence

“…One particularly appealing synthetic strategy to design efficient CPL emitters has consisted in developing chirally perturbed π-extended achiral chromophores, mostly based on C 2 -symmetric chiral moieties (chiral binaphthyl or 1,2-diamino-cyclohexane derivatives) linked to bodipy or perylene organic dyes (Tsumatori et al, 2010;Langhals et al, 2011;Kumar et al, 2013Kumar et al, , 2014Kumar et al, , 2015bSánchez-Carnerero et al, 2014;Sheng et al, 2016). In addition, helicenes have recently shown to be very good scaffolds for the development of emissive materials with strong CPL activity (Gingras, 2013;Chen and Shen, 2016;Dhbaibi et al, 2018Dhbaibi et al, , 2020Zhao et al, 2019;Shen et al, 2020). Following this approach, we recently reported helical π-conjugated helicenediketopyrrolopyrrole (DPP) dyes [P-H6(DPP) 2 and (P,P)-DPP(H6DPP) 2 , Figure 1] (Dhbaibi et al, 2018) as red CPL emitters, (Shen et al, 2014;Saleh et al, 2015;Pascal et al, 2016;Sakai et al, 2016;Biet et al, 2017;Nishimura et al, 2017) arising from an intramolecular exciton coupling (Berova et al, 2012) between the achiral DPP units placed within the chiral environment of the helicene.…”