The first mixed-valent aAntimony(III/V) oxo clusters (2,6-Mes2C6H3Sb)2(ClSb)4O8 and (2,6-Mes2C6H3Sb)4(ClSb)4(HOSb)2O14

The kinetically controlled base hydrolysis of the sterically encumbered arylantimony dichloride 2,6-Mes(2)C(6)H(3)SbCl(2) (1) under aerobic conditions afforded [2,6-Mes(2)C(6)H(3)(Cl)Sb-III](2)O (2) and the mixed-valent clusters (2,6-Mes(2)C(6)H(3)Sb(V))(2)(ClSbIII)(4)O-8 (3) and (2,6-Mes(2)C(6)H(3)Sb(V))(4)(ClSbIII)(4)(HOSbIII)(2)O-14 (4), whose molecular structures are dominated by hypervalent and secondary bonding.