Bridging 1,2-Bis(diphenylphosphino)methane Ligands Facilitate the Formation of Binuclear Complexes with Both Two-Coordinate and Three-Coordinate Gold(I) Ions.

Five new crystalline gold(I) complexes β-Au(μ-dppm)Br·2CHCl (), [Au(μ- dppm)Br]Br·2CHCl (), [Au(μ-dppm)Br](PF) (), [Au(μ-dppm)Cl](BPh)·3CHCl () and [Au(μ-dppm)]Cl(AsF)·2CHCl () (where dppm is bis(diphenylphosphino)methane) have been prepared and structurally characterized by single crystal X-ray diffraction. Colorless β-Au(μ-dppm)Br·2CHCl () has centrosymmetric structure with two three-coordinate gold(I) ions held in close proximity by the dppm ligands. Crystals of [Au(μ- dppm)Br]Br·2CHCl (), [Au(μ-dppm)Br](PF) (), and [Au(μ-dppm)Cl](BPh)·3CHCl () have a cation with an unusual arrangement that binds a two-coordinate gold(I) ion to a three-coordinate gold(I) ion through an aurophilic interaction.

Molecular Flexibility in Solvated Crystals of the Dimer, Au(μ-1,2-bis(diphenylphosphino)ethane)I, with Three-Coordinate Gold(I).

We report the ability to trap the dimer Au(μ-dppe)I (dppe is 1,2-bis(diphenylphosphino)ethane) with different separations between the three-coordinate gold ions in crystalline solvates. All of these solvates ((Au(μ-dppe)I·4(CHCl) (), Au(μ-dppe)I·2(CHCl) (), the polymorphs α-Au(μ-dppe)I·2(HC(O)NMe) () and β-Au(μ-dppe)I·2(HC(O)NMe) (), and Au(μ-dppe)I·4(CHCl) ()) along with polymeric {Au(μ-dppe)I}·(CHCl) ()) originated from the same reaction, only the solvent system used for crystallization differed. In the different solvates of Au(μ-dppe)I, the Au···Au separation varied from 3.