Dithienylethene-bridged difluoroboron β-diketonate dyes: Optical switching behaviors and triple sensing for volatile amine vapors

Developing new visible light-triggered NIR photochmmic sensors for the accurate detection of volatile amine vapors in the solid state is highly desirable. Herein, three novel dithienylethene-bridged difluomboron beta-diketonate dyes Di-BF(2)bdk-UTE1-Di-BF(2)bdk-UTE3, in which BF(2)bdk group not only functions as electron acceptor but also responds to amine vapors, have been developed. Upon alternating irradiation with blue light (460-470 nm) and near-infrared light (760-770 nm), they displayed excellent NIR photochmmism and fluorescent switching behaviors in toluene and in the PMMA film. Moreover, they showed an unprecedented triple sensing performance for volatile n-pmpylamine vapor in the PMMA film state (fluorescent-colorimetric-colorimetric). Therefore, they would be utilized as triple sensing membranes for selective detection towards volatile primary or secondary amine vapors in environmental and biological systems.