Übergangsmetall-methylen-komplexe: LIV. Eine ruthenium-ruthenium-doppelbindung: Synthese und methylen-addition

The first organometallic compound containing a reactive multiple bond between the ruthenium atoms has been synthesized by nitrosylation of a carbonylmetal precursor. Treatment of (η⁵-C₅H₅)Ru(CO)₂]₂ (1) with nitrogen monoxide in n-decane at 170°C gives the black, air-stable nitrosyl derivative (η₅ -C₅H₅)Ru(μ-NO)]₂ (2) in 75–80% yield. The composition of this molecule as well as the subsequent addition of a bridging methylene group with formation of (μ-CH₂)η⁵C₅H₅)Ru(NO)]₂ (3a) shows that a metal—metal double bond is present in compound 2; this molecule is thus isostructural with the known iron analogue (η⁵-C₅H₅)Fe(μ-NO)]₂.