Experimental and theoretical comparison of the metallophilicity between d(10)-d(10) Au(I)-Hg(II) and d(8)-d(10) Au(III)-Hg(II) interactions.

The heteronuclear Au(I)/Hg(II) complexes [Hg{AuR(μ-2-C6H4PPh2)}2] [R = C6F5 (1), C6Cl2F3 (2)] were prepared by reacting [Hg(2-C6H4PPh2)2] with [AuR(tht)] (1:2) and further transformed into the Au(III)/Hg(II) species [Hg{Au(C6F5)Cl2(μ-2-C6H4PPh2)}2] [R = C6F5 (3), C6Cl2F3 (4)] by the addition of 2 equiv of PhI·Cl2. The crystal structures of 1-3 display Au···Hg(II) interactions, which in the case of 3 is the first Au(III)···Hg contact described to date. Theoretical calculations on model systems of the C6F5 derivatives evidence that the attraction between Au(I) or Au(III) and Hg(II) arise from dispersion-type interactions and that both contacts are of the same strength.