Bridging and chelating diphosphine ligands in Ru3(μ-H)(μ-N=CPh2)(CO)8(P-P).: X-ray diffraction structures of Ru3(μ-H)(μ-N=CPh2)(CO)8(dmpe) and Ru3(μ-H)(μ-N=CPh2)(CO)8(bpcd)

Treatment of the azavinylidene-bridged cluster Ru-3(mu-H)(mu-N=CPh2)(CO)10 ( 1) with the diphosphine ligand bis(dimethylphosphino) ethane (dmpe) gives Ru-3(mu-H)(mu-N=CPh2)( CO) 8( dmpe) ( 2) in moderate yield, while the ligand 4,5-bis(diphenylphosphino)4-cyclopenten-1,3-dione (bpcd) reacts with Ru-3(mu-H)(mu-N=CPh2)(CO)(10) in the presence of Me3NO to furnish Ru-3(mu-H)(mu-N=CPh2)(CO)(8)(bpcd) ( 3) in low yield. Each new cluster has been isolated and characterized in solution by IR and NMR (H-1 and P-31) spectroscopies, and the coordination mode exhibited by the ancillary diphosphine ligand in 2 and 3 has been established by X-ray crystallography. Ru-3(mu-H)(mu-N=CPh2)(CO)(8)(dmpe) crystallizes in the monoclinic space group P2(1)/c; a = 10.791(1) Angstrom, b = 16.377(1) Angstrom, c = 18.148(1) Angstrom, beta = 96.675(2)degrees, V = 3185.3(4) Angstrom(3), Z = 4, D-cacl = 1.791 Mg/m(3); R = 0.0360, R-w = 0.0866 for 7522 observed reflections with I > 2sigma(I). Ru-3(mu-H)(mu-N=CPh2)(CO)(8)(bpcd) crystallizes, as the CH(2)C(l)2 solvate, in the triclinic space group P(1) over bar, a = 11.956(1) Angstrom, b = 14.228(1)degrees A, c = 31.409(3) Angstrom, alpha = 89.377(2)degrees, beta = 79.344(2)degrees, beta = 77.235(2)degrees, V = 5118.4(8) Angstrom(3), Z = 2, D-calc = 1.670 Mg/m(3); R = 0.0557, R-w = 0.1069 for 10977 observed reflections with I > 2sigma( I). The structural details of clusters 2 and 3 are contrasted with Ru-3(mu-H)(mu-N=CPh2)(CO)(7)(mu-dppm)(eta-dppm), which is the only known structurally characterized phosphine-substituted cluster of this genre.