Electron Transfer Induced C S Bond Cleavage in Rhenium and Technetium Thioether Complexes: Structural and Chemical Evidence for π Back‐Donation to C S σ* Orbitals

摘要: The trends in carbon‐sulfur bond length for complexes of 1,4,7‐trithiacyclononane (9S3) provide compelling evidence that CS σ* orbitals accept π‐electron density from the metal. As the metal d‐orbital energy and occupancy increase, this leads ultimately to cleavage of the CS bonds with concomitant release of ethene in the Re and Tc complexes [Eq. (a)].