Experimental and Theoretical Comparison of the Metallophilicity between d¹⁰–d¹⁰ Au^I–Hg^II and d⁸–d¹⁰ Au^III–Hg^II Interactions

The heteronuclear AuI/HgII 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 AuIII/HgII 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···HgII interactions, which in the case of 3 is the first AuIII···Hg contact described to date. Theoretical calculations on model systems of the C6F5 derivatives evidence that the attraction between AuI or AuIII and HgII arise from dispersion-type interactions and that both contacts are of the same strength.