Synthesis and crystal structure of the phenyl-substituted diantimonide PhSb23- in the ammoniate [Cs6(PhSb2)2] · 11NH3

The highly charged diatomic anions Pn24-(Pn=PtoBi) of the group 15 elements are known only in solids like Cs4Sb2. However, if the overall charge is reduced by introducing a phenyl residue, an anion like PhSb23- may be crystallised as a thermally unstable ammoniate. In analogy to the original Zintl chemistry, the compound [Cs6(PhSb2)2] · 11NH3 forms by reducing triphenylantimony with a solution of caesium in liquid ammonia.