STRUCTURE AND CHEMISTRY OF THE COMPLEX TETRAKIS(ETA-5-PENTAMETHYLCYCLOPENTADIENYL)TETRAKIS(MU-3-CHLORO)-TETRARUTHENIUM(II) - A USEFUL PRECURSOR TO (PENTAMETHYLCYCLOPENTADIENYL)RUTHENIUM(0), (PENTAMETHYLCYCLOPENTADIENYL)RUTHENIUM(II), AND (PENTAMETHYLCYCLOPENTADIENYL)RUTHENIUM(IV) COMPLEXES

A single-crystal X-ray structural analysis of the complex [Cp*Ru(µ3-Cl)]4 (1, Cp* = ƞ5-C6(CH3)6) has been performed (triclinic, PI (No. 2); o = 11.281 (5); b = 11.354 (4); c = 18.846 (5) Å α = 82.20 (2)°, β = 82.03 (3)°, γ= 65.45 (4)° V = 2166.3 Å3, Z = 2). The complex contains a distorted cubic array of ruthenium and chlorine atoms. The complex 1 is a useful precursor to Ru(0), Ru(II), and Ru(IV) pentamethylcyclopentadienyl complexes. Reaction of 1 with donor ligands yields Cp*RuL2Cl complexes (L = CO, Pi(CH3)3. With dienes, 1 yields the complexes Cp*Ru(ƞ4-diene)Cl (diene = 1,3-butadiene, 1,3-pentadiene, trans-2,trans-4-hexadiene, 2,3-dimethyl-l,3-butadiene, 2,3-diphenyl-1,3-butadiene, 1,3-cyclohexadiene, 1,3-cycloheptadiene, 1,5-cyclooctadiene, norbornadiene) which in turn can be reduced with lithium to yield the corresponding anionic diene complexes Cp*Ru(ƞ4-diene)~Li+-DME (DME = 1,2-dimethoxyethane). The complex [Cp*Ru(µ3-I)]4 has also been prepared and reacts with 1,3-butadiene to yield Cp*Ru(ƞ4-s-cis-l,3-butadiene)I, which has been structurally characterized by a single-crystal X-ray analysis (monoclinic b, P2j/c (No. 14); α = 7.177 (2); b= 14.362 (3); c=13.788 (2) Å β= 93.39 (1)° V= 1418.7 Å3, Ζ — 4). Reaction of 1 with ethylene yields the complex [Cp*Ru(ƞ2-C2H4)Cl]I, which can be converted to the complex Cp*Ru(ƞ2) -C2H4)2Li. With allyl chloride, 1 yields the oxidative addition product Cp*Ru(ƞ3-C3H5)C12. © 1990, American Chemical Society. All rights reserved.