Experimental and Theoretical Evidence of the Existence of Gold(I)⋅⋅⋅Mercury(II) Interactions in Solution through Fluorescence‐Quenching Measurements

Heteronuclear complexes {[Hg(R) 2 ][Au(R′)(PMe 3 )] 2 } n (R=R′=C 6 Cl 2 F 3 ( 3 ); R=R′=C 6 F 5 ( 4 ); R=C 6 Cl 2 F 3 , R′=C 6 F 5 ( 5 ); R=C 6 F 5 , R′=C 6 Cl 2 F 3 ( 6 )) were prepared by the treatment of the corresponding organomercury compounds, [Hg(C 6 X 5 ) 2 ], with two equivalents of [Au(C 6 X 5 )(PMe 3 )]. Their crystal structures, as determined by using X‐ray diffraction methods, display Au⋅⋅⋅Hg interactions. Although only compound 4 and 5 show luminescence in the solid state, all of these compounds quench the fluorescence of naphthalene in solution. Solution studies of these derivatives suggest a cooperative effect of the gold(I) center in switching on the quenching capabilities of the [Hg(C 6 X 5 ) 2 ] synthon with naphthalene. Theoretical studies confirmed the quenching ability of the organomercury species in the presence of gold.