Formation and Structure of the [(1,2‐C6H4P2Sb)2]4− Ion: Implications for an Extended Family of Isoelectronic Main‐Group Radicals

A fine pair: Quadruple deprotonation of 1,2-(PH2)2C6H4 with Sb(NMe2)3/nBuLi gives the 6π-aromatic ion [1,2-C6H4P2Sb]−, which is converted by one-electron reduction into the radical [1,2-C6H4P2Sb].2− (see picture). DFT calculations reveal that dimerization of the radical is only favored if ionic interactions with cations are considered.