Testing cuprophilicity with tetrahedral ruthenium hydride carbonyl clusters

The reaction of [NEt4]3 [HRu4(CO)12] (1) with three mole equivalents of [Cu(MeCN)4][BF4] and three mole equivalents of [NEt4]Br affords a nearly 1:1 mixture of [NEt4]3 [HRu4(CO)12(CuBr)3] (2) and [NEt4]2 [H2Ru8(CO)24Cu7Br3] (3). These two products can be separated owing to their different solubilities in organic solvents. [NEt4]3 [HRu8(CO)24Cu6Br2] (4) has been obtained reacting 1, [Cu(MeCN)4][BF4] and [NEt4]Br with stoichiometry 1:1:3. In the absence of [NEt4]Br, 1 reacts with 3.5 mole equivalents of [Cu(MeCN)4][BF4] affording [Ru5(CO)15(CuMeCN)2] (5). The new clusters 2–5 have been fully characterized by FT-IR and 1H NMR spectroscopy, and their molecular structures elucidated by single-crystal X-ray diffraction (SC-XRD). Homometallic Ru-Ru and Cu-Cu as well as heterometallic Ru-Cu interactions have been computationally investigated by DFT methods.