The reaction of ferrocenylacetylene with (v-C5R5)LzRuCl [R = H or Me; LO = 2PPh3, Ph2-PCH2CH2PPh2 (dppe), or (Ph2PCsHd2Fe (dppf)] in the presence of NH4PF6 and the subsequent treatment with alkali gave ruthenium(I1) ferrocenylacetylide complexes (~-C~R~) L~R U C C F C in good yields. Cyclic voltammetric data suggest the large electron delocalization between the Fe atom of the ferrocene moiety and the Ru(I1) atom in their one-electron-oxidized complexes. The IR spectra of the oxidized ferrocenylacetylide complexes and the molecular structure of [ (v-C5H5)(Ph3P)2Ru(CCFc)]PF6 determined by X-ray diffraction gave an evidence for such electron delocalization. Crystallographic data for 12 are as follows: space group E d a , a = 17.176(9) A, b = 12.055(7) A, c = 22.480(9) A, P = 101.35(4)', V = 4563(4), 2 = 4. The complexesshowed low-energy absorption bands assigned to intervalence transfer transitions in the nearinfrared (NIR) region. The parameter a2, which shows the degree of ground-state delocalization

The reaction of RcC⋮CH [Rc = (η5-C5H5)Ru(η5-C5H4)] with RuClL2(η5-C5R5) [R = H or Me; L2 = 2PPh3 or Ph2PCH2CH2PPh2 (dppe)] in the presence of NH4PF6 and subsequent treatment with base gave Ru(II) ruthenocenylacetylide complexes RcC⋮CRuL2(η5-C5R5) in good yields. In a similar manner, the pentamethylruthenocene analogues, Rc‘C⋮CRuL2(η5-C5R5) [Rc‘ = (η5-C5Me5)Ru(η5-C5H4)], were also prepared. Cyclic voltammograms of the complexes showed two reversible one-electron-oxidation processes, consisting of the processes [Ru(II)Ru‘(II)] to [Ru(III)Ru‘(II)] and then to [Ru(III)Ru‘(III)]. Chemical oxidation of the complexes induced novel structural rearrangement. The two-electron oxidation of complex RcC⋮CRu(PPh3)2(η5-C5H5) afforded a kind of allenylidene complex, a cyclopentadienylidenethylidene complex, [(η5-C5H5)Ru{μ-η6:η1-C5H4CC}Ru(PPh3)2(η5-C5H5)]2+, in 90% yield. The one-electron oxidation of Rc‘C⋮CRu(PPh3)2(η5-C5H5) gave the vinylidene complex (Rc‘CHC)Ru(PPh3)2(η5-C5H5) in 62% yield, while the two-electron oxidation led to the fulvene−vinylidene complex [(η6-C5Me4CH2)Ru{μ-η5:η1-C5H4CHC}Ru(PPh3)2(η5-C5R5)]2+ by an intramolecular hydrogen transfer in 59% yield.

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