Fluoride Ion Chelation by a Bidentate Phosphonium/Borane Lewis Acid
Document Type
Article
Publication Date
8-20-2008
Journal / Book Title
Journal of the American Chemical Society
Abstract
The phosphonium borane [1-Mes2B-2-MePh2P-(C6H4)]+ ([2]+) has been synthesized as an iodide salt by alkylation of 1-Mes2B-2-Ph2P-(C6H4) with MeI. This novel cationic borane complexes fluoride to afford the corresponding zwitterionic fluoroborate complex 1-FMes2B-2-MePh2P-(C6H4) (2-F) with a binding constant in MeOH exceeding that of 1-Mes2B-4-MePh2P-(C6H4) ([1]+) by at least 4 orders of magnitude. Structural and computational results indicate that the high fluorophilicity of [2]+ arises from both Coulombic and cooperative effects which lead to formation of a B-F→P interaction with a F→P distance of 2.666(2) Å. These results, which are supported by NBO and AIM analyses, show that the latent phosphorus-centered Lewis acidity of the phosphonium moiety in [2]+ can be exploited to enhance fluoride binding via chelation.
DOI
10.1021/ja804492y
Montclair State University Digital Commons Citation
Hudnall, Todd W.; Kim, Young Min; Bebbington, Magnus; Bourissou, Didier; and Gabbaï, François P., "Fluoride Ion Chelation by a Bidentate Phosphonium/Borane Lewis Acid" (2008). Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works. 367.
https://digitalcommons.montclair.edu/chem-biochem-facpubs/367
