Dithienylethenes functionalized by triphenylethene and difluoroboron β-diketonate fragments: Synthesis, optical switching behavior and fluorescent turn-on sensing for volatile organic amines

Abstract

Two novel dithienylethenes were obtained by appending triphenylethene and BF2bdk moieties at the termini of dithienylethene unit (TDBB and TDTB), in which BF2bdk group not only functions as electron acceptor (A) but also responds to volatile organic amines. Only TDBB displayed excellent visible light-triggered photochromism and fluorescent switching behavior in toluene and in the PMMA film upon alternating irradiation with blue light (460–470 nm) and near-infrared light (760–770 nm). More importantly, they displayed a distinct fluorescent turn-on and colorimetric sensing performance for volatile n-propylamine in THF. Specially, the addition of excessive n-propylamine can effectively modulate their photochromic properties in THF. And their PMMA films showed the fluorescent turn-off and colorimetric sensory behavior towards n-propylamine vapor. Consequently, they would be utilized as novel dual sensory materials for volatile primary or secondary amine vapors in the environment and biological systems.