Fluoride Binding by a Neutral Organoantimony(V) Lewis Acid Embedded within a Dibenzodithiophene Chromophore

Organoantimony Lewis acids have been coveted for their ability to bind hard anions like fluoride in competing media. Herein, we describe the synthesis of a phenyl dithienostibole ( 1 ) in which the antimony(III) center is embedded within a planar dibenzodithiophene chromophore. Compound 1 reacts with o ‐chloranil to form the corresponding catecholatostiborane ( 2 ); it also reacts with tert ‐butyl peroxide in the presence of perfluoropinacol to form the corresponding pinacolatostiborane ( 3 ). Compound 2 was investigated as a platform for anion binding. UV–vis titrations in CH 2 Cl 2 afforded an association constant greater than 10 7 M −1 pointing to the high fluoridophilicity of this new system. Density functional theory calculations highlight the role played by the σ *(Sb‐C phenyl ) orbital in imparting Lewis acidity to the antimony center of 2 .