Persistent antimony- and bismuth-centered radicals in solution

Shintaro Ishida; Fumiya Hirakawa; Ko Furukawa; Kenji Yoza; Takeaki Iwamoto

doi:10.1002/anie.201405509

Persistent antimony- and bismuth-centered radicals in solution

Angew Chem Int Ed Engl. 2014 Oct 13;53(42):11172-6. doi: 10.1002/anie.201405509. Epub 2014 Jul 27.

Authors

Shintaro Ishida¹, Fumiya Hirakawa, Ko Furukawa, Kenji Yoza, Takeaki Iwamoto

Affiliation

¹ Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578 (Japan). sishida@m.tohoku.ac.jp.

PMID: 25066471
DOI: 10.1002/anie.201405509

Abstract

Stibinyl and bismuthinyl radicals are recognized as representative intermediates of antimony and bismuth compounds, but still elusive in the condensed phase. We successfully synthesized persistent stibinyl and bismuthinyl radicals in solution by facile dissociation of the corresponding dimers with bulky substituents. We characterized the radicals by NMR and UV/Vis spectroscopy and estimated the thermodynamic parameters for the dissociation equilibria. The radicals show n→p (HOMO→SOMO) transition bands at 497 nm (stibinyl) and 543 nm (bismuthinyl) in 3-methylpentane and react with a stable nitroxyl radical to give the cross-radical coupling products in good yields.

Keywords: antimony; bismuth; dimerization; persistent radicals; pnictogens.