Cluster chemistry. LIX. Stereochemistry of group 15 ligand-substituted derivatives of M3(CO)12 (M=Ru, Os). D*. Synthesis and characterisation of some tetra-substituted ruthenium complexes: X-ray structures of Ru3(CO)8(L)4 (L=PMe2Ph and P(OR)3, R=Me, Et and Ph)

Article abstract of DOI:10.1016/0022-328X(89)88009-X

Several tetra-substituted derivatives of Ru3(CO)12 have been synthesised, and the molecular structures of Ru3(CO)8(L)4 (L=PMe2Ph and P(OR)3, R=Me, Et, Ph) have been determined by single-crystal X-ray diffraction methods.The non-carbonyl ligands occupy equatorial positions in the Ru3 triangle, one on each of two metal atoms, and two on the third.Twisting of the ML4 moieties about the Ru-Ru bonds is found, leading to the presence of one μ-CO ligand in the PMe2Ph and P(OEt)3 complexes; the latter also has two semi-bridging CO ligands about the other two Ru-Ru bonds.The PMe2Ph and P(OEt)3 complexes exhibit 50/50 disorder of the Ru3 core about a crystallographic inversion centre; the P(OMe)3 complex has a similar 15/85 disorder in the Ru3 core, and also in two of the OMe groups on one P(OMe)3 ligand.A discussion of the major structural features of M3(CO)_12-n(L)_n (n=1-4) is given.Crystal data: Ru3(CO)8(PMe2Ph)4, triclinic, P1, a 12.040(2), b 10.482(6), c 9.549(4) Angstroem, α 86.26(4), β 69.69(3), γ 78.72(3) deg, U 1108.4(6) Angstroem³, Z=1, N₀ (number of observed data with I>3?(I))=2056, R=0.076, R'=0.075; Ru3(CO)8(P(OMe)3)4, monoclinic, P2₁, a 9.821(2), b 17.384(6), c 10.912(3) Angstroem, β 94.88(2) deg, U 1856(1) Angstroem³, Z=2, N₀=2726, R=0.041, R'=0.046; Ru3(CO)8(P(OEt)3)4, monoclinic, C2/c, a 18.987(6), b 12.465(4), c 22.244(7), Angstroem, β 102.03(3) deg, U 5149(3) Angstroem³, Z=4, N₀ (I>2?(I))=1729, R=0.066, R'=0.048; Ru3(CO)8(P(OPh)3)4, monoclinic, P2₁/c, a 21.14(1), b 13.820(9), c 27.24(3) Angstroem, β 106.34(6) deg, U 7637(7) Angstroem³, Z=4, N₀ (I>2?(I))=6107, R=0.073, R'=0.052.