The binuclear ruthenium complex (Me2-SiSiMe2)[(η5-C5H4)Ru(CO)]2(μ-CO)2(3) was obtained in poor yield by reaction of Ru3(CO)12 with C5H5Me2-SiSiMe2C5H5 in boiling heptane. A thermal rearrange-ment reaction of 3 in heptane afforded the complex [(Me2Si)(η5-C5H4)Ru(CO)2]2 (4), which was evidently formed via a metathesis between Si-Si and Ru-Ru bonds in 3. Molecular structures of 3 and 4 have been determined by X-ray diffraction.

Thermal treatment of the prydyl side-chain-func-tionalized cyclopentadiense with Fe(CO)5 and Ru3(CO)12 gave different intramolecular C-H activated products, in addittion to the normal dinuclear metal complexs. Reactions of the dinuclear metal complexs with I2 also gave different metal iodide complexes.

Thermal treatment of 1,2-bis(3-tert-butylcyclopentadieny1) tetramethyldigermane with [Fe(CO)5] in xylene gave the diiron complex [Fe2(CO)2(μ-CO)2(μ-3-t-BuC5H3Me2GeGeMe2C5H3Bu-t-3)] 1 existing as a mixture of cis and trans isomers (1c and 1t) which were separated by preparative TLC. When the two isomers were heated in xylene the cis substrate (1c) rearranged to a trans product [Fe2(CO)4(μ-3-t-BuC5H3GeMe2)2] 2t, while the trans substrate (1t) afforded a cis product 2c. This indicated that the rearrangement reaction is stereospecific, which is consistent with previous results. Molecular structures of 1c, 1t, 2t, and 2c were determinde by X-ray diffraction.

A series of doubly bridged bis(cyclopentadienyl) tetracarbonyl diiron complexes (7-13) have been synthesized by the reaction of the corresponding ligand (1-6) with Fe(CO)5 in refluxing xylene. It is unusual that the reaction of ligand (GeMe2)(GeMe2)(C5H4)2 (3) with Fe(CO)5 gave the complex (GeMe2)[η5-C5H4)Fe(CO)]2(μ-CO)2 (10) as the main product which lost the GeMe2, only a small amount of the expected product (GeMe2)2[(η5-C5H3)Fe(CO)]2(μ-CO)2 (9) was obtained. The molecular structures of 9 and (SiMe2SiMe2)2[(η5-C5H3)Fe(CO)]2(μ-CO)2 (13) have been determined by X-ray diffraction.