Effect of vinylene bond geometry on the molecule packing and aggregation-enhanced emission property of a pair of 1-[(9-anthracenyl)vinyl]pyrene isomers

Both trans and cis-1-[(9-anthracenyl)vinyl]pyrene isomers display an aggregation-induced enhanced emission behavior. The vinylene bond geometry exerts important effects on the molecule packing and solid emission efficiency. A new pair of 1-[(9-anthracenyl)vinyl]pyrene (AVP) isomers was simultaneously obtained in a ratio of about 10:1. They cannot be separated by chromatography. However, they can be more effectively separated via sublimation. Both isomers display an aggregation-induced enhanced emission character, which is mainly due to a large increase in the radiative decay rate. The vinylene bond geometry brings different packing motifs. The interacting adjacent molecules in trans-AVP crystals can adopt both edge-to-face and face-to-face arrangements. In contrast, in cis-AVP crystals the adjacent molecules are inclined to adopt an edge-to-face arrangement. The molecule packing plays an important role in the solid emission efficiency.