Crystal and molecular structures of M(3)(mu(3)-eta(2)-PhC(2)C CPh)(mu-CO)(CO)(9) (M=Ru and Os)

The molecular structures of M(3)(mu(3)-eta(2)-PhC(2)C=CPh)(mu-CO)(CO)(9) (M = Ru and Os) are described: these complexes are similar to several mono-alkyne derivatives, with one C=C triple bond of the diyne ligand attached in the 2 eta(1),eta(2)-(parallel to) mode to the closed triangular M(3) core. The M-M edge parallel to the complexed C=C triple bond is asymmetrically bridged by a CO ligand; the coordination about each M atom is completed by three terminal CO ligands. Crystals of the isomorphous Os [Ru] complexes were triclinic, space group <P(1)over bar> (C-i(1), No. 2), a 18.869(9) [18.881(5)], b 9.164(3) [9.188(3)], c 8.548(2) [8.595(6)] Angstrom, alpha 65.73(2) [66.00(3)], beta 78.53(3) [78.43(4)], gamma 87.25(3) [87.58(2)]degrees, Z 2. 7323 [3638]observed data [I > 3 sigma(I)] were refined to R 0.031 [0.030] and R(w) 0.036 [0.032].