Synthesis, chemical characterization, and molecular structure of Au-8{Fe(CO)(4)}(4)(dppe)(2) and Au6Cu2{Fe(CO)(4)}(4)(dppe)(2)

The new Au-8(Fe(CO)(4))(4)(P<^>P), and Au6Cu2(Fe(CO)(4))(4)(P<^>P)(2) (P<^> P= dppm, dppe) neutral cluster compounds were isolated in good yields by co ndensation of the [Au-3(Fr(CO)(4))(2)(P<^>D)](-) anions with Au(SEt2)Cl and CuCl, respectively, and have been characterized by IR, NMR and microanalys es. The molecular structures of Au-8( Fe(CO)(4))(4)(dppe)(2) and Au6Cu2( Fe (CO)(4))(4)(dppe)(2) have been determined by X-ray diffraction studies. Bot h molecules adopt a stereogeometry of the heavy atoms consisting of a trian gulated and corrugated ribbon twisted around the elongation direction. Cont rary to the expectations the latter displays the two copper atoms in the si tes of highest connectivity. This implies that site exchange between copper and gold occurs during the synthesis.