Syntheses, Properties, and X-ray Crystal Structures of Iron and Ruthenium Compounds with the η5-C5Me4CF3Ligand. Compounds of the Type [(η5-C5Me4CF3)M(μ-CO)(CO)]2(M = Fe, Ru)

(Trifluoromethyl)tetramethylcyclopentadiene, ΗC 5 Me 4 CF 3 (Cp ⧧ H), reacts with Ru 3 (CO) 12 in refluxing n -decane to produce [(η 5 -C 5 Me 4 CF 3 )Ru(μ-CO)(CO)] 2 ( 1 ). In chlorinated hydrocarbon solutions, 1 reacts with the solvents in the presence of visible light to produce [(η 5 -C 5 Me 4 CF 3 )Ru(CO) 2 (Cl)] ( 3a ). Compound 1 reacts with iodine in refluxing CH 2 Cl 2 to produce [(η 5 -C 5 Me 4 CF 3 )Ru(CO) 2 (I)] ( 3b ). The X-ray crystal structure of compound 3b is presented. Compound 3b reacts with triphenylphosphine in refluxing ethanol to produce [(η 5 -C 5 Me 4 CF 3 )Ru(CO)(PPh 3 )(I)] ( 4 ). The HC 5 Me 4 CF 3 ligand reacts with Fe(CO) 5 in refluxing heptane to produce [(η 4 -HC 5 Me 4 CF 3 )Fe(CO) 3 ] ( 5 ). Compound 5 represents a new mode of coordination (η 4 ) for HC 5 Me 4 CF 3 . The spectroscopic properties of compound 1 and its previously reported iron analog, [(η 5 -C 5 Me 4 CF 3 )Fe(μ-CO)(CO)] 2 ( 2 ), are compared with those of their η 5 -C 5 H 5 and η 5 -C 5 Me 5 “parent” analogs of the type [(η 5 -C 5 R 5 )M(μ-CO)(CO)] 2 (M = Fe, Ru). Compounds 1 and 2 were characterized by single-crystal X-ray crystallography and found to be in the trans configuration with respect to the η 5 -C 5 Me 4 CF 3 rings. Overall, the spectroscopic and X-ray structural data of 1 and 2 support the previous conclusions that the η 5 -C 5 Me 4 CF 3 ligand is electronically equivalent to η 5 -C 5 H 5 and sterically equivalent to η 5 -C 5 Me 5 . Compounds 1 and 3b represent important synthons for subsequent ruthenium chemistry with the η 5 -C 5 Me 4 CF 3 ligand.