Enantiomerically Pure C2-symmetric Dinuclear Silver(I) and Copper(I) Complexes from a Bis(2,2′-bipyridine)-substituted 9,9′-Spirobifluorene Ligand

Dedicated to Professor Rolf Saalfrank on the occasion of his 70th birthday We have prepared a new bis(bipyridyl) ligand 1 based on a chiral 9,9′-spirobifluorene core in both enantiomerically pure forms. This ligand was found to undergo diastereoselective self-assembly to optically pure dinuclear coordination compounds upon coordination to copper(I) and silver(I) ions. Surprisingly, however, the resulting diastereomer was not found to be D2-symmetric which is usually found for similar bis(bidentate) ligands, but rather C2-symmetric with differently configurated metal centers.