Doped organic charge-transfer cocrystal with tunable fluorescence of wide band emission

• We use quantum chemistry method to analyze and select structurally matched components. • Select structural complementary donor/acceptor pairs and dopant to further tune their fluorescence luminescence colors. • The optical properties and structures of the synthesized cocrystals with different doping ratios were studied. Supramolecular crystals with tunable fluorescence emission have been demonstrated for many applications. Guided by quantum chemical calculations, a series of (TCNB) x (OFN) 1-x (Cor) doped cocrystals were synthesized by charge transfer induced self-assembly with coronene (Cor) as electron donor and octafluoronaphthalene (OFN) or 1,2,4,5-tetracyanobenzene (TCNB) as electron acceptors. Structural similarity between OFN-Cor and TCNB-Cor are necessary for full proportion doping of (TCNB) x (OFN) 1-x (Cor). Based on experimental and theoretical analysis, doped cocrystals can be tuned in photophysical properties (luminescent color, fluorescence lifetime, quantum yield). With the doping ratio increasing, the doped cocrystals emit fluorescent in different colors from blue to yellow and then to orange. Through molecular design to select and synthesize organic fluorescent materials is an efficient strategy to deeply understand their structure–activity relationship, which pave a potential path to develop novel functional supramolecular systems.