Intramolecular Through-Space Interactions Induced Emission of Pillar[4]arene[1]dicyanobenzene
Chunli Song, Zheng Li, Jia‐Rui Wu, Tong Lu, Ying‐Wei Yang
Abstract
Macrocycles modified with donor (D)–acceptor (A) motifs are generally believed as advanced organic fluorophores with exceptional photophysical properties. However, it is still necessary to develop intrinsic D–A-type macrocycles without complicated modifications due to their significant implications in fabricating high-performance emissive materials. Herein, we report on the photoluminescence properties of pillar[4]arene[1]dicyanobenzene (P5-2CN), a pillar[5]arene derivative containing one p-phenylene dicyano unit. The rigid pillar conformation and nonconjugated architecture endow P5-2CN with unanticipated intramolecular through-space charge transfer (TSCT) and aggregation-induced emission properties, by which the ratio of locally excited state emission and TSCT emission can be easily affected by their residing environment. Intriguingly, P5-2CN solid powder displays a profound vaporchromic behavior for common nitrile vapors with different hydrocarbon chain lengths. Experimental and theoretical analyses reveal that intramolecular through-space conjugation is critical for such unusual photoluminescence.