Tetranuclear stiboxanes (RSb)4O6, exhibiting an adamantane-type structure

Abstract

Depolymerization reactions of organostibonic acids with protic ligands have been investigated. Reaction of arylstibonic acids with 8-hydroxyquinoline (8-HQ), or {2-[1H-pyrazol-5(3)-yl]naphthalene-1-ol} (H₂naphpz) in a 1 : 1 stoichiometry in refluxing toluene affords adamantane-like L₄(RSb)₄O₆ clusters [(p-XC₆H₄Sb)₄(O)₆(Q)₄] (where X = Cl (1), Br (2), QH = 8-hydroxyquinoline), [(p-ClC₆H₄Sb)₄(O)₆(Hnaphpz)₄]·H₂naphpz (3) and [(p-Br-C₆H₄Sb)₄(O)₆(Hnaphpz)₄]₂·H₂naphpz (4). Further a tetrameric organoantimony oxo cluster, L₄(RSb)₄O₄ [(p-ClC₆H₄Sb)₄(O)₄(naphpz)₄] (5) has also been isolated as a side product in the reaction of arylstibonic acid with naphthylphenolic pyrazole. Interestingly 1–4 structurally resemble the dimeric form of the antimony oxide Sb₂O₃ and its mineral senarmontite.