Molecular Complexes Featuring Unsupported Dispersion-Enhanced Aluminum-Copper and Gallium-Copper Bonds

摘要

The reaction of the copper(I) β-diketiminate copper complex {(Cu(BDI~(Mes)))_2(μ-C_6H_6)} (BDI~(Mes) = N,N′-bis(2,4,6-trimethylphenyl)pentane-2,4-diiminate) with the low-valent group 13 metal β-diketiminates M(BDI~(Dip)) (M = Al or Ga; BDI~(Dip) = N,N′-bis(2,6-diisopropylphenyl)pentane-2,4-diiminate) in toluene afforded the complexes {(BDI~(Mes))CuAl(BDI~(Dip))} and {(BDI~(Mes))-CuGa(BDI~(Dip)}. These feature unsupported copper-aluminum or copper-gallium bonds with short metal-metal distances, Cu-Al = 2.3010(6) A and Cu-Ga = 2.2916(5) A. Density functional theory (DFT) calculations showed that approximately half of the calculated association enthalpies can be attributed to London dispersion forces.