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Two piezochromic molecules, (2Z,4E)-2-(4-(Diphenylamino)phenyl)-5-phenylpenta-2,4-dienenitrile (1a) and (2Z,4E)-2-(4-(acridin-10(9H)-yl)phenyl)-5-phenylpenta-2,4-dienenitrile (1b), were synthesized by using Knoevenagel and Buchwald-Hartwig cross-coupling reactions. Their piezochromic fluorescence behavior was tuned by subtle structural change. The system indicates typical intramolecular charge-transfer properties. The luminescence intensity of 1a decreased with increasing pressure with the redshift of the emission wavelength when the hydrostatic pressure in a diamond anvil cell (DAC) was applied on its crystal. However, the emission wavelength of 1b which has a methylene unit more than 1a had no obvious shift and the intensity increased gradually at the pressure range from 0.66 GPa to 5.72 GPa.

An enantioselective tandem Michael addition/ cyclization reaction between trisubstituted 2-nitro-1,3-enynes and cyclic 1,3-diketones catalyzed by a chiral organosquaramide catalyst in the presence of Ag2CO3 was developed. The chiral functionalized chromene products could be obtained in good yield and in 80-99% enantiomeric excess. The structures and absolute configurations of some of the products were confirmed by X-ray crystallographic analysis.

A series of triphenylethylene-based luminophoric molecules were efficiently synthesized. The substituent effect of the fluorophores on their photophysical properties was then investigated. Consequently, it was found that longer conjugated system and larger molecular dipole of the donor–π–acceptor fluorophores could result in bathochromic shifts of UV–vis absorption and emission bands, so do the Stokes shifts. Especially, full-color fluorescent emissions in both solution and solid states could be achieved by changing conjugation length and substituents with different electron-donating or accepting abilities in the triphenylethylene skeleton. The density functional theory calculations further demonstrated that with the increase of the electron-donating or accepting abilities of the substituents, the energy gaps of the fluorophores gradually decreased, which elucidated the substituent effect of the organic fluorophores on their photophysical properties.

An efficient Knoevenagel condensation reaction was used to construct a series of α-cyano-α,ω-diaryloligovinylenes, which show prominent fluorescence emission in the solid state. On investigating the effect of conjugation length on fluorescent properties, we found that the diene structure showed superior solid-state luminescence. Furthermore, the emission color could be adjusted by introducing donor or acceptor functional groups at the terminal aryl groups. Full-color emission in the visible region can be achieved by adding different functional groups to the α-cyano-α,ω-diaryldivinylene moiety. The structure-property relationships were elucidated and some observations such as the substitution position effects were discussed. These compounds have potential applications as full-color solid emissive candidates in material science and their simple structures allow them to be easily modified resulting in further interesting properties.