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

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} (H(2)naphpz) in a 1 : 1 stoichiometry in refluxing toluene affords adamantane-like L-4(RSb)(4)O-6 clusters [(p-XC6H4Sb)(4)(O)(6)(Q)(4)] (where X = Cl (1), Br (2), QH = 8-hydroxyquinoline), [(p-ClC6H4Sb)(4)(O)(6)(Hnaphpz)(4)]center dot H(2)naphpz (3) and [(p-Br-C6H4Sb)(4)(O)(6)(Hnaphpz)(4)](2)center dot H(2)naphpz (4). Further a tetrameric organoantimony oxo cluster, L-4(RSb)(4)O-4 [(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.