Selective and Sensitive Fluoride Detection through Alkyne Cruciform Desilylation

Desilylation of silylethynyl-substituted benzobisoxazole cruciforms can be achieved using stoichiometric amounts of fluoride, leading to a significant change in their UV-vis absorption and fluorescence. This response is observable at micromolar concentrations of fluoride, and, in the case of a triisopropylsilyl-substituted cruciform fluorophore, extraordinarily selective for fluoride over other small inorganic anions, including hydroxide, acetate, and phosphate.