Silver(I) complexation of (poly)aromatic ligands. Structural criteria for depth penetration into cis-stilbenoid cavities

Silver(I) complexes with aromatic donors an thoroughly analyzed (with aid o f the Cambridge Crystallographic Database) to identify the basic structural factors inherent to the bonding of an arene ligand. Most strikingly, the d istance parameter d (which simply measures the normal separation of Ag from the mean aromatic plane) is singularly invariant at d = 2.41 +/- 0.05 Angs trom for all silver/arene complexes, independent of the hapticity (eta (1) or eta (2)), hybridization, or multiple coordination. As such, a systematic series of stilbenoid ligands has been successfully designed to precisely m odulate the penetration of silver(I) into the ligand cleft, and a multicent ered poly(arene) ligand (X) designed to form a one-dimensional assembly of Ag/arene units. Simply stated, the depth penetration of silver(I) into the aromatic cavities of various cis-stilbenoid donors can be precisely predict ed with a single parameter gamma that measures the separation of the two co facial aryl groups comprising the cleft. This simple geometric consideratio n must be taken into account in any successful-design of novel (poly)aromat ic ligands for silver(I) complexation to constitute new molecular architect ures.