Design for a small molecule based chemosensor containing boron and pyridine moieties to detect HF

[Display omitted] •A novel triarylborane compound 1 is reported for detection of HF with high sensitivity and selectivity.•The appended pyridyl groups were efficiently enhanced the complexation ability of 1 towards HF.•The spin-coated compound 1 film was applied to detect HF gas via a unique capacitance change within a fast response time. A new triarylborane compound 1 is described as fluorescent probe for HF gas with high sensitivity and selectivity. The system utilized the coordination of a fluoride ion to the boron center in 1 to cause perturbation in the energy transfer pathway and the π conjugation, which induced distinct fluorescent quenching. A probe 1-coated film was further applied to detect HF gas via a unique capacitance change.