The synthesis and optical properties of four new triarylborane–dipyrromethane (TAB–DPM) conjugates (3a–d) containing dual binding sites (hydrogen bond donor and Lewis acid) have been reported. The new compounds exhibit a selective fluorogenic response towards the F⁻ ion. The NMR titrations show that the anions bind to the TAB–DPM conjugates via the Lewis acidic triarylborane centre in preference to the hydrogen bond donor (dipyrromethane) units.