Transpositional Circularly Polarized Luminescence from Transient Charge-Transfer Coassembly.

Abstract

Charge-transfer (CT) complexation between electron-rich and deficient aromatics has been widely applied in functional optical and photovoltaic materials. The selective complexation and spontaneous disassociation behavior of a dynamic charge-transfer coassembly possess potential in designing smart and dynamic luminescent materials, which however have not been addressed so far. In this work, the transient charge-transfer driven coassembly between π-conjugated amino acids and tetracyanobenzene, showing dynamic luminescent transition and circularly polarized luminescence (CPL) evolution property, is illustrated. Transient coassembly behaviors are independent to the diverse binding sites covering fluorene, naphthalene, and anthracene, attributed to the intramolecular CH…π interaction. Incorporation of fluorescent dyes enables a transient light harvesting process with hyperchromic CPL properties. Spontaneous green-to-red CPL transition hydrogels are also fabricated by embedding a competitive CT donor. Using a polymeric matrix treated by organic solvents, charge-transfer coassembly is immobilized with diverse circularly polarized luminescence. Such sensitive complexation shows applications in moisture-responsive luminescent materials and multiple luminescent color evolutions are realized.