The first mononuclear h8 -coordinated pentalene complex: synthesis and molecular structure of [Ta\{ h8 -C8H4(siMe3)2-14\}CI3]

Treatment of [TaCl2Me3] with Li2(cot¿) (cot¿ = 1,4-bis(trimethylsilyl)cyclooctatetraene] affords [Ta(¿-cot¿)Me3], which reacts with [NHPri2Et]Cl in dichloromethane to yield the complex [Ta{¿8-C8H4(SiMe3) 2-1,4}Cl3]; X-ray crystallography shows the latter to contain a pentalene ligand bound through all eight carbons to a single tantalum centre.