Unprecedented eta(3)-M-3 coordination mode in a terpyridine ligand

The gold(I) complex [Au-3(C6F5)(3)(eta(3)-Fcterpy)] (Fcterpy = 4'-ferrocenyl-2,2':6',2-terpyridine) represents the first example of a terpyridine ligand bonded to three different metals. The aurophilic interactions present in the molecule may contribute to the overall stability of the system, as was shown by DFT calculations. The positive Mayer indices (0.152 and 0.138), as well as the magnitude of the binding interaction between terpy and the Au(I)L fragments, support this interpretation.