In-situ photoisomerization for aggregation-induced emission of dibiphenyl fumaronitrile

• A novel fumaronitrile core-based π-conjugated molecule comprising two biphenyl aggregation-induced emission activators was synthesized
• Emission from the Z-isomer was more intense than that of the E-isomer due to conformational restriction.
• In-situ photoisomerization in the H2O-induced aggregated state proceeded successfully upon light illumination.

The synthesis and photochemical characteristics of a fumaronitrile (FN)-based π-conjugated molecule, dibiphenyl fumaronitrile (BP-FN), comprising two biphenyl aggregation-induced emission (AIE) activators linked by an FN core were investigated. Upon illumination with a UV light, the emission from the Z-isomer, (Z)BP-FN, was more intense than that of the E-isomer, (E)BP-FN, due to conformational restriction of the former. (E)BP-FN exhibited J-aggregation behavior in mixed THF–H2O solvents when the H2O content exceeded 70 vol%, illustrative of typical AIE characteristics. (Z)BP-FN presented significant aggregation causing quenching in emission when the H2O content exceeded 80 vol%. In-situ photoisomerization of (E)BP-FN to (Z)BP-FN proceeded successfully even in the H2O-induced aggregated state in THF solution; however, the emission of the in-situ photoisomerized (Z)BP-FN aggregates was significantly quenched in solutions with high H2O contents of above 80 vol%.

In-situ photoisomerization of (E)BP-FN to (Z)BP-FN proceeded successfully even in the H2O-induced aggregated state in THF solution, exhibiting aggregation induced emission and aggregation causing quenching emission in (E)BP-FN and (Z)BP-FN aggregates, respectively.Figure optionsDownload as PowerPoint slide