η5–η1 ring slippage of [OsCp2] (Cp = η5-C5H5) and [Ru(η5-ind)2] (ind = indenyl) resulting from reaction with the ruthenium(VI) nitride [Ru(LOEt)(N)Cl2] (1; LOEt– = [CoCp{P(O)(OEt)2}3]−) is reported. The treatment of [OsCp2] or [Ru(η5-ind)2] with 1 resulted in η5-η1 ring slippage of the cycloolefin ligands and formation of the trinuclear nitrido complexes [Cp(η1-C5H5)Os(NRuLOEtCl2)2] (2) or [(η5-ind)(η1-ind)Ru(NRuLOEtCl2)2] (3).