“…One metal thereby is functioning as an activating neighboring group for the second metal center through reversible transannular interactions.1 These effects are quite pronounced also in a number of gold(I) complexes of dppm-type ligands2'5 (A), or, e.g., related 1,3-difunctional phosphinobis(methylide) metallacycles (C).6'11 Oxidation with equivalent quantities of halogen leads to some of the very few species with gold in the oxidation state +11 containing an Au-Au bond.5,8'11 With dihalomethane, stepwise oxidative addition takes place leading eventually to methylene bridging between Au(III) centers.12,13 For the gold(I) complexes of type A-C, X-ray structure data,2,3,6,14 UV/vis spectra,15 and 197Au Móssbauer re-sults4,5'16 have indicated that Au-Au interactions are not negligible, since, e.g., the two metal atoms have even shorter interatomic distances than the dimensions imposed by the ligand bite. The nature of this interaction has been the subject of very recent discussions, as experimental evidence is rapidly increasing not only for the limited field of A-frame complexes.17 (4) Schmidbaur, H.; Wohlleben, A.; Wagner, F.; van de Vondel, D. F.; van der Helen, G. P. Chem. Ber.…”