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Chiral organic fluorescent materials have attracted broad attention for their application in various chiroptical devices. Helicenes possess special helical structure and unique optical properties, and have been utilized to develop chiral organic fluorescent materials with excellent chiroptical performance. However, the low luminescence efficiency of helicene-based chiral fluorescent materials in solid state limits their practical applications. In this work, chiral organic fluorescent emitters with helicene moiety have been developed from binaphthanol structure. These BINOL [4]helicene compounds display aggregation-enhanced emission properties, and have strong blue emission in solid state with fluorescent quantum yield up to 0.67. The DFT calculation reveals that these compounds have highly twisted molecular structures. Thus, the excellent fluorescent properties in solid state could be aroused by the highly contorted molecular structures, which could limit the π-π stacking of adjacent molecules in solid state. The enantiomers of these compounds show strong Cotton effects in circular dichroism spectra, and the molecules with 4-methoxy phenyl moiety exhibit circularly polarized luminescence properties. Highly twisted BINOL- [4]helicene hybrids have been synthesized, which have strong fluorescent emission in solid state and chiral optical properties. [Display omitted] • Chiral binol-[4]helicene hybrids have been synthesized. • These molecules display aggregation-enhanced emission properties. • These molecules show strong fluorescent emission in solid state. • Compound 6 exhibits circularly polarized luminescence property. [ABSTRACT FROM AUTHOR]

Highly planar organic emitters have been developed from 4-styrylbenzonitrile structure, which show strong AIE properties and deep blue emission in solid state with good to excellent fluorescence quantum efficiency. [Display omitted] • 4-Styrylbenzonitrile derivatives are synthesized. • These planar fluorophores show strong AIE properties. • These compounds are efficient deep blue emitters in solid states with high quantum yields. Organic fluorescent molecules with π-conjugated system have shown great importance in numerous applications including bioimaging and optoelectronics. Planar aggregation-induced emissive (AIE) organic compounds with efficient solid-state luminescence are rarely developed and urgently needed in various applications. In this work, highly planar 4-styrylbenzonitrile derivatives have been synthesized. Most of these compounds show strong AIE properties with hundred-fold fluorescent enhancement. Moreover, these molecules are deep blue emissive in solid state, exhibiting good to excellent fluorescence quantum efficiency. The single crystal analysis shows that adjacent molecules could form special J-type aggregation. The intramolecular rotations are efficiently restricted by various noncovalent interactions. These molecular arrangements could be essential for the observed strong emission in aggregated and solid state. This work has paved a new path to efficient AIE-active organic emitters with highly planar conformations from 4-styrylbenzonitrile structure. [ABSTRACT FROM AUTHOR]