A bidentate Lewis acid with a telluronium ion as an anion-binding site.
The search for receptors that can selectively capture small and potentially toxic anions in protic media has sparked a renewed interest in the synthesis and anion-binding properties of polydentate Lewis acids. Seeking new paradigms to enhance the anion affinities of such systems, we synthesized a bidentate Lewis acid that contains a boryl and a telluronium moiety as Lewis acidic sites. Anion-complexation studies indicate that this telluronium borane displays a high affinity for fluoride in methanol. Structural and computational studies show that the unusual fluoride affinity of this bidentate telluronium borane can be correlated with the formation of a B-F → Te chelate motif supported by a strong lone-pair(F) → σ*(Te-C) donor-acceptor interaction. These results, which illustrate the viability of heavier chalcogenium centres as anion-binding sites, allow us to introduce a novel strategy for the design of polydentate Lewis acids with enhanced anion affinities.
Zhao
Haiyan
H
Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, USA.
Gabbaï
François P
FP
D000143:Acids / Q000737:chemistry*; D000838:Anions; D001665:Binding Sites; D002614:Chelating Agents / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D013056:Spectrophotometry, Ultraviolet; D013691:Tellurium / Q000737:chemistry*
D000143:Acids; D000838:Anions; D002614:Chelating Agents; D013691:Tellurium