Extension of the Pnictinous Acid Series: Rational Synthesis of a Stibinous Acid and Exploration of Its Reactivity

Higher-valent oxyacids of heavier main-group elements readily polymerize because of their ability to expand their coordination spheres and the polarity of their terminal E–O (E = P, As, Sb, Bi) bonds. As a result, no free R₂SbO₂H stibinic acids have yet been prepared.

Lower-valent R₂SbOH stibinous acids should be less susceptible to such polymerization, but there are no reported rational syntheses of molecules belonging to this class. We report here the first controlled synthesis and isolation of a molecular stibinous acid, Dipp₂SbOH, where Dipp = 2,6-diisopropylphenyl. We also report an initial exploration of the chemistry of this class of compounds, including their Brønsted acidity and Lewis basicity.