Nanofibers generated from nonclassical organogelators based on difluoroboron β-diketonate complexes to detect aliphatic primary amine vapors

Abstract

New D–A–D type difluoroboron β-diketonate complexes with terminal triphenylamines ABA, ABVA and AVBVA were synthesized. It was found that stable organogels could be gained from ABVA and AVBVA without traditional gelation groups in mixed solvents containing 1,4-dioxane, and balanced π–π interactions were the driving forces for the gel formation. Interestingly, the organogels based on ABVA and AVBVA exhibited emission close to the NIR (near infrared) region. To the best of our knowledge, such narrow band gap low molecular-weight π-gelators have not been reported. In particular, xerogel-based films generated from ABVA and AVBVA could be used as sensors to detect gaseous aliphatic primary amines with high performance. For example, after exposing to saturated n-butylamine and n-propylamine vapors for 30 s, the emission of the films was quenched completely and new strong emission at ca. 560 nm appeared on account of the decomposition of the difluoroboron β-diketonate complexes.