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′)(PMe3)]2} n (R=R′=C6Cl2F3 ( 3); R=R′=C6F5 ( 4); R=C6Cl2F3, R′=C6F5 ( 5); R=C6F5, R′=C6Cl2F3 ( 6)) were prepared by the treatment of the corresponding organomercury compounds, [Hg(C6X5)2], with two equivalents of [Au(C6X5)(PMe3)]. 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(C6X5)2] synthon with naphthalene. Theoretical studies confirmed the quenching ability of the organomercury species in the presence of gold. [ABSTRACT FROM AUTHOR]