Coordination chemistry of perhalogenated cyclopentadienes and alkynes: Part XXV. Synthesis and molecular structure of [C5H2(SiMe3)3-1,2,3]Mn(CO)3, the first complex with a 1,2,3-tris-(trimethylsilyl)cyclopentadienyl ligand

Treatment of [C5H4Cl]Mn(CO)3 with a large excess of nBuLi and SiMe3Cl yields the chloro-bis(trimethylsilyl)cyclopentadienyl complex [C5H2Cl(SiMe3)2]Mn(CO)3 (1) as a mixture of the 1-2,5- and 1-2,4-isomers 1a and b with the former clearly dominating (71:29). Further addition of excessive tBuLi and SiMe3Cl yields a complex product mixture, from which the title compound [C5H2(SiMe3)3-1,2,3]Mn(CO)3 (2) can be isolated in up to 20% yield. The molecular structures of 1a and 2 have been determined by X-ray crystallography.