AbstractReactions of silver(I) and copper(I) 1,1,1,5,5,5‐hexafluoroacetylacetonate (hfacac) with dienes1, 2and3resulted in some stable complexes. All of them showed an equal molar ratio of hfacac to diene per coordinated metal ion. The structure of Ag(hfacac)(1)(THF)6was solved by X‐ray diffraction analysis. The complex crystallized in the monoclinic space group P21/n with a = 6.342(3), b = 32.891(7), c = 11.680(2) Å, and z = 4. It was mononuclear with inclusion of a solvent molecule. Since the C2vsymmetry of3retained upon forming both silver(I) and Cu(I) complexes, a fast equilibrium of dissociation/recombination must have happened in the solutions. The changes of1H and13C NMR chemical shifts caused by coordination were meas