Coordination of Asymmetric Diborenes towards Cationic Coinage Metals (Au, Ag, Cu).

Synthesis of a series of cationic coinage metal (Au: 2-4, Ag: 5, and Cu: 6) complexes of asymmetric diborenes (1 a, 1 b) is reported. X-ray diffraction analysis reveals that the metal center interacts unsymmetrically with the B2 moiety and the terminal boron atom exhibits pronounced pyramidal geometry. A computational study shows that in complexes 2-6, the bonding between the B2 units and the metal center is dominated by electrostatic interactions concomitant with non-negligible covalent contributions.