“Aurophilicity” as a Consequence of Relativistic Effects: The Hexakis(triphenylphosphaneaurio)methane Dication [(Ph₃PAu)₆C]^2⊕

Abstract

The class of “porcupine compounds”, includes the title cation 1, whose structure has been determined as the BPh4 salt. The analytically, mass-spectrometrically and crystallographically detected interstitial C atom occupies the crystallographic inversion center in an octahedron composed of gold atoms: the structure is probably stabilized by AuċAu interactions. The periphery of tetraauriomethanes is apparently “aurophile” with respect to further LAu⊕ ions, so that the hypervalent complex cation [C(AuL)6]2⊕ is formed spontaneously. The supposedly uncentered octahedral cluster cations formulated previously as (AuL) were in fact probably indentical with the C-centered species described here.