Add to ORKGR factor = 0.069; wR factor = 0.190; data-to-parameter ratio = 22.1. In title salt, C38H34P2 2+2IO4, the P atoms of the dication and the I atoms of the periodate anions are each in a slightly distorted tetrahedral environment. In the dication, the two – P(C6H5)3 groups adopt a gauche conformation with respect to each other. In the crystal, several C—H O hydrogen bonds between the cations and anions lead to a two-dimensional arrangement along (101). Related literature For the synthesis and structures of related compounds, see: Barkell et al. (2008); Rizzoli et al. (2010)