Photochemical synthesis of olefin-carbonylosmium complexes: serendipitous formation of a 1,2-diosmacyclobutane derivative

Reversible C-H bond activation at a triosmium centre: A comparative study of the reactivity of unsaturated triosmium clusters Os 3 (CO) 8 (μ-dppm)(μ-H) 2 and Os 3 (CO) 8 (μ-dppf)(μ-H) 2 with activated alkynes

“…Scheme 1 highlights the results of the reaction of cluster 1 with the two alkynes. The formation of dinuclear products in this reaction is consistent with that observed from the photochemical reaction of Os 3 (CO) 12 with DMAD [36]. Compounds 3a and 3b were the only products isolated when the same reactions were carried out in toluene at 110 °C.…”

ENDOR characterization of an iron–alkene complex provides insight into a corresponding organometallic intermediate of nitrogenase

“… 4 Specifically, these structures have high local symmetry at C1 that is consistent with the ENDOR measurements for the AA bound to FeMo-co in PA . In contrast, a binding mode in which the vinyl carbon atoms (C1 and C2) of the AA product each bind to a different Fe ion (dimetallacyclobutane) would be nonplanar (as in a known diosmium complex 29 ), rendering the two C1 protons stereoelectronically and magnetically inequivalent.…”

Dalton perspectives. The generation and reactivity of versatile ruthenium carbonyl organometallic intermediates by cluster photochemistry

“…Irradiation of [Os3(CO) ,] 2 in the presence of a large excess of methyl acrylate results in the formation of both the q2-olefin complex [Os(CO),(CH,CHCO,Me)] 15 and of the dinuclear osmacyclobutane [Os,(CO),(CH CHC0,-Me)] 16. 31 The 0s-0s bond length in 16 is 2.885 A, typical for a 0s-0s single bond and the length of the p-ethane-l,2-diyl bridge is that of a single C-C bond. The four-membered ring is puckered presumably to relieve the steric strain of the Os(CO), moieties resultant from a planar, eclipsed, conformation.…”