Reactions of substituted tetramethylcyclopentadienes with molybdenum hexacarbonyl

The reactions of the substituted tetramethylcyclopentadienes [C5Me4HR] [R = ethyl (1), n-propyl (2), i-propyl (3), cyclopentyl (4), cyclohexyl (5), 4-NMe2Ph (6)] with Mo(CO)6 in refluxing xylene gave the corresponding dinuclear metal carbonyl complexes [η5-C5Me4R]2Mo2(CO)6 (7–11), while similar treatment of [C5Me4H(4-NMe2Ph)] (6) with Mo(CO)6 afforded an unexpected product [(η5-C5Me4(4-NMe2Ph))MoO2]2(μ-O) (12). All the new complexes were fully characterized. The molecular structures of 7, 8, 11 and 12 have been determined by X-ray single crystal diffraction.