title: Persistent antimony- and bismuth-centered radicals in solution.
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.
authors: Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578 (Japan). sishida@m.tohoku.ac.jp.
authors: Shintaro
authors: S
authors: Ishida
authors: Fumiya
authors: F
authors: Hirakawa
authors: Ko
authors: K
authors: Furukawa
authors: Kenji
authors: K
authors: Yoza
authors: Takeaki
authors: T
authors: Iwamoto
keywords: antimony; bismuth; dimerization; persistent radicals; pnictogens