The reaction of the [N(PPh,),] + salt of [Ru,(CO),(B,H,)] -with [Ru,(CO),,(NCMe),] yielded both the octahedral [Ru,(CO),,B] -I and trigonal-prismatic [RU,H,(CO),,B] -2 boride cluster anions. This result indicates that the choice of the trigonal-prismatic versus octahedral cage is not determined by the size of the interstitial atom. The salt [ N (PPh,),] [Ru,H,(CO),,B] has been structurally characterised. The reactions of anions 1 and 2 with [AuCI(PPh,)], [AuCI{P(C,H,Me-z),}], [{(Ph,P)Au},O] [BF,] and [{(Z-MeC,H,),PAU},O] [BF,] have been studied and the distribution of the products [Ru,(CO),,B(Au( PR,)}], starting cluster has been examined. The trigold derivatives are best prepared by treating the octahedral anion 1 with [{(Ph,P)Au},O] +. Single-crystal X-ray crystallography has confirmed that each of the gold(i) phosphine derivatives has an octahedral Ru,B core. [RU6H(CO)16B{AU(PR3)}2] and [~U6(co)16B{AU(PR3)}3] as a function Of R (Ph or Z-MeC,H,) and Of the Transition-metal clusters which encapsulate p-block atoms '-' are well documented but carbide clusters predominate. '-, In terms of regular, closed polyhedra, a hexametallic framework is typically either an octahedron (86 valence electrons) or, less often, a trigonal prism (90 valence electrons). In cobalt and rhodium chemistry the trigonal-prismatic cluster carbide is repre~ented.~.~-" However, within the Group 8 triad, the trend observed for hexametallic clusters incorporating p-block elements has tended to suggest that a first-row atom (B,,,12-15 C,'-3 N4,') prefers to reside within an octahedral M, cage, while the trigonal-prismatic cage is observed when the interstitial atom is a larger p-block atom, e.g. p h o s p h ~r u s . ~, ' ~* ' Recently, we published preliminary information regarding the reaction of [N(PPh,),][Ru,(CO),(B,H,)] with [RU,(CO)~ o(N-CMe),]. Significantly, this reaction gives both the octahedral boride cluster [RU,(CO)~ 7B]-1 13,19 and the trigonalprismatic cluster [Ru,H,(CO),,B)-2. We now present a full report of this work, and describe reactions of anions 1 and 2 with the gold(1) phosphines [AuCI(PR3)] and [{(R,P)Au],O][BF,] (R = Ph or 2-MeC6H4), all of which lead to hexaruthenium boride derivatives with octahedral cluster cores.
ExperimentalGeneral Data.-Fourier-transform NMR spectra were recorded on a Bruker WM 250 or AM 400 spectrometer; 'H shifts are reported with respect to 6 0 for SiMe,, 'B with respect to 6 0 for F,B-OEt, and 31P with respect to 6 0 for H3PO4. All spectral data listed in the Experimental section are recorded at 298 K. All downfield chemical shifts are positive. Infrared spectra were recorded on a Perkin Elmer FT 1710 spectrophotometer, FAB (fast atom bombardment) and FIB (fast ion bombardment) mass spectra on Kratos instruments with 3nitrobenzyl alcohol as matrix.