(DIMETHYLARSINO)PHENYLCHROMIUM TRICARBONYL AS A SOURCE OF (BENZYNE)CHROMIUM TRICARBONYL - THE NOVEL STRUCTURES OF RU3(CO)8(MU-H)((3)-ETA(2)-[(ETA(6)-C6H4)CR(CO)3])(MU-ASME2) AND RU2(CO)6(MU-H)((3)-ETA(2)-[(ETA(6)-C6H4)CR(CO)3])(MU-ASME2)

The pyrolysis of Ru3(CO)11L,L = AsMe2C6H5Cr(CO)3, affords Ru3(CO)8(mu-H){mu3-eta2-[(eta6-C6H4)Cr(CO)3]}(mu-ASMe2) (5) and Ru2(CO)6(mu-eta2-[(eta6-C6H4)Cr(CO)3]}(mu-AsMe2) (6). In 5 the (benzyne)chromium tricarbonyl moiety is unsymmetrically bound to the closed RU3 triangle; in 6 the same group acts as a two-electron-donating o-phenylene derivative. A Ru-Cr bond is present in 5 but not in 6. Crystals of 5are triclinic, a = 10.322(2) angstrom, b = 13.290(2) angstrom, c = 9.536(1) angstrom, a = 91.23(1)-degrees, beta = 95.89(1)-degrees, gamma = 101.89(1)-degrees, Z = 2, space group P1BAR, and those of 6 are monoclinic, a = 10.862(1) angstrom, b = 14.655(2) angstrom, c = 14.590(3) angstrom, beta = 107.57(1)-degrees, Z = 4, space group P2(1)/c. The structures were solved by heavy-atom methods and were refined by full-matrix least-squares procedures to R = 0.027 for 6446 and 4577 reflections with I greater-than-or-equal-to 3sigma(I), respectively.