Metal-Sulfur Chemistry - Aurophilicity
Jones, W.; Yuan, J.; Narayanaswamy, R.; Young, M.; Elder, R.; Bruce, A.; Bruce, M. Solid State EXAFS and Luminescence Studies of Neutral, Dinuclear Gold(I) Complexes. Gold(I)-Gold(I) Interactions in the Solid State Inorg. Chem. 1995, 34, 1996.
Narayanaswamy, R.; Young M. A.; Parkhurst, E.; Ouellette, M.; Kerr, M. E.; Ho, D.; Elder, R. C.; Bruce, A. E.; Bruce, M. R. M. Synthesis, Structure Determination, and Electronic Spectroscopy of Neutral, Dimeric Gold(I) Complexes. Gold(I)-Gold(I) Interactions in Solution and in the Solid State Inorg. Chem., 1993, 32, 2506-2517.
We conducted variable-temperature P-31 NMR experiments between -80 and 20 °C to measure an activation barrier involving a Au(I)-Au(I) interaction at 10 ± 1 kcal/mol. The scheme below illustrates how formation of a Au(I)-Au(I) interaction changes energy levels. Notice as the Au—Au interaction forms (going from left to right) the energy decreases between the occupied sulfur orbital (HOMO) and the unoccupied gold orbital (LUMO). This decrease brings the electronic transition into the visible region. We used this to explain the yellow color of our gold complex.