Mononuclear Ru/Os Compounds: Ruthenocenes and Osmocenes

Facile η5–η1 Ring Slippage of the Cycloolefin Ligands in Osmocene and Bis(η5-indenyl)ruthenium(II)

“…Although osmocene, [OsCp 2 ] where Cp = η 5 -cyclopentadienyl, has been known for a long time, its reaction chemistry has not been well explored . Electron-rich [OsCp 2 ] can be oxidized readily to higher-valent osmocenes such as dinuclear [(OsCp 2 ) 2 ] 2+ , [(OsCp 2 S) 2 ] 2+ , and [{OsCp­(η 5 -C 5 H 4 )} 2 ] 2+ containing Os–Os single bonds and mononuclear [OsCp 2 (X)] n + [X = neutral ( n = 2) or anionic ( n = 1) ligand], , indicating its potential for multielectron transfer.…”

“…Although osmocene, [OsCp 2 ] where Cp = η 5 -cyclopentadienyl, has been known for a long time, its reaction chemistry has not been well explored . Electron-rich [OsCp 2 ] can be oxidized readily to higher-valent osmocenes such as dinuclear [(OsCp 2 ) 2 ] 2+ , [(OsCp 2 S) 2 ] 2+ , and [{OsCp­(η 5 -C 5 H 4 )} 2 ] 2+ containing Os–Os single bonds and mononuclear [OsCp 2 (X)] n + [X = neutral ( n = 2) or anionic ( n = 1) ligand], , indicating its potential for multielectron transfer. Our interest in high-oxidation-state osmocene complexes is stimulated by a recent report that [OsCp 2 ] can mediate the photochemical oxidation of water, possibly via CpOs IV oxo or hydroxo intermediates. , This finding suggests that osmocene derivatives containing metal–ligand multiple bonds can display rich redox and catalytic chemistry.…”