Luminescent chiral molecular glasses by melt-quenching enantiopure BINAP
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Date
2025-11-23
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Abstract
Chiral organic glasses combine unique optical properties with the processing advantages of amorphous solids. Here, melt-quenching as a strategy for preparing optically active glasses from enantiopure BINAP (2,2′-bis(diphenylphosphino)-1,1′-binaphthyl), a pivotal ligand in asymmetric catalysis and for luminescent metal complexes is demonstrated. Thermal characterization reveals that only R-BINAP and S-BINAP, not rac-BINAP, form molecular glasses with glass transition temperatures near 100 °C. Pair distribution function analysis and circular dichroism confirm the retention of local structure and homochirality despite the loss of long-range order. Remarkably, the glassy state has a beneficial influence on the molecular optoelectronic properties relative to the crystalline state, resulting in an increase of the radiative rate constant by ≈30%, attributed to more favourable Franck-Condon factors. In addition, a highly unusual simultaneous enhancement of circularly polarized luminescence (CPL) by nearly an order of magnitude is observed, achieving dissymmetry factors |glum| approaching 10−2 that are competitive with the top-performing purely organic molecular chiral emitters reported to date. These findings establish melt-quenched chiral molecular glasses as promising platforms for advanced optoelectronic and photonic materials, combining exceptional chiroptical properties, strong luminescence, and processability without the constraints of crystallinity.
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amorphous materials, circularly polarized luminescence, melt-quenching, molecular glasses, optical materials
Subjects based on RSWK
Amorpher Festkörper, Lumineszenz, Zirkularpolarisation, Schmelzen, Quenching, Optischer Werkstoff