Alkyl and Alkylidyne Complexes of Rhenium

The multiplicity of its oxidation states enables the element rhenium to fix numerous ligand types in stable complexes. The synthesis of “Cp^*ReClMe₃” now completes the series of Re^v complexes “Cp^*ReCl_nMe_4–n”. The neopentyl complex 1 reacts with C₅H₅TiCl₃ to give the paramagnetic carbyne complex 2, which can be smoothly oxidized to the diamagnetic complex 3. Complexes 2 and 3 are the first π‐cyclopentadienylcarbyne complexes with rhenium in high oxidation states (Re^VI and Re^VII, resp.). Cp^* = η⁵‐C₅(CH₃)₅. (Figure Presented.)