Synthesis and structural characterisation of the first bis(bora)calixarene: a selective, bidentate, fluorescent fluoride sensor

A bis(bora) calixarene, 3, the first lower-rim boron derivatised calixarene to be structurally characterised, is synthesised by the reaction of PhBCl2 with 4-tert-butylcalix[4] arene, and is demonstrated to be a sensitive and selective fluorescent fluoride sensor.