16406-48-7Relevant articles and documents
Photoreactions of the Triruthenium Cluster HRu3(CO)10(μ-COCH3). Isomerization of the Bridging Alkylidyne Ligand and Competing Ligand Substitutions
Friedman, Alan E.,Ford, Peter C.
, p. 551 - 558 (1989)
Irradiation of the title compound HRu3(CO)10(μ-COCH3) (A) in hydrocarbon solution under CO leads to the formation of the bridging μ,η2 acyl isomer HRu3(CO)10(μ,η2-C(O)CH3) (B).Quantum yields for isomerization φi were wavelength dependent ranging from CO 1.0 atm.In addition, over the range 0-1.0 atm, the φi values proved to be linearly dependent on PCO despite the absence of a stoichiometric requirement for CO in the isomerization.A key observation was that photoisomerization of A 13C labeled specifically at the bridging alkylidyne carbon, i.e., HRu3(CO)10(μ-13COCH3), gives B specifically labeled at the bridging acyl carbon, i.e., HRu3(CO)10(μ,η2-13C(O)CH3), with no evidence of scrambling of the label with other carbons in the complex.Photolysis in the presence of 13CO or other added ligands demonstrated the lability of the cluster coordinated carbonyls to photosubstitution reactions.The quantum yield for photosubstitution φs follows the same wavelength dependence as does φi, and it is proposed that the two processes result from competitive decay pathways of common intermediates.Limiting quantum yields for photosubstitution are about 0.25.A mechanism for these reactions related to that proposed previously for the photofragmentation of the parent triruthenium cluster Ru3(CO)12 is discussed.Prolonged 313-nm irradiation of HRu3(CO)10(μ,η2-C(O)CH3) under CO leads to cluster fragmentation and the formation of Ru(CO)5 plus acetaldehyde.
C-H bond-making and -breaking processes in heteronuclear monoazadienyl complexes: Reactivity of HFeRu(CO)5{RC=C(H)C(H)=N-iPr} toward CO
Beers, Olaf C. P.,Elsevier, Cornelis J.,Kooijman, Huub,Smeets, Wilberth J. J.,Spek, Anthony L.
, p. 3187 - 3198 (2008/10/08)
In the photochemically induced reaction of Ru2(CO)6{RC=C(H)CH2N-iPr} (1a, R = Ph; 1b, R = Me) with Fe2(CO)9 the heteronuclear complex HFeRu(CO)5{RC=C(H)C(H)=N-iPr} (5) is formed in 35 % yield. HRu2(CO)6{RC=C(H)C(H)=N-iPr} (4), which is prepared quantitatively by photolysis of H2Ru4(CO)8{RC=C(H)C(H)=N-iPr}2 under a CO atmosphere, can act as an intermediate in this reaction and is proposed to be formed from 1 by a β-H-elimination reaction. Complex 5 is most likely formed via oxidative addition of the Ru-H bond in 4 to a Fe(CO)4 fragment. Complex 5 reacts with CO at 293 K to give reductive elimination of the monoazadiene ligand and formation of Fe(CO)5/Ru3(CO)12, probably via a mechanism involving opening of the hydride bridge. In the reaction of 5 with CO at 373 K the hydride is shifted to the monoazadienyl (MAD-yl) ligand, which is reduced from formally monoanionic to dianionic. In the case of R = Ph selective hydride transfer to Cβ is observed, resulting in the formation of FeRu(CO)6-{PhC(H)C(H)C(H)N-iPr} (6a), which features an unprecedented coordination mode of the MAD-yl ligand. For R = Me, both transfer to Cβ (affording 6b) and to Cim is observed, the latter affording FeRu(CO)6{MeC=C(H)CH2N-iPr} (7). This R-group dependence and also the difference in the reactivity of 5 and its homonuclear Ru2 analogue 2 is rationalized by the strength of the π-C=C coordination in the intermediate HFeRu(CO)6{RC=C(H)C(H)=N-iPr} (9). Complex 9a could not be prepared by the reaction of [FeRu(CO)6(PhC=C(H)C(H)=N-iPr}][BF4] (8a) with NaBH4, which afforded one diastereomer of FeRu(CO)6{PhCC(H)C(H)N-(H)-iPr} (10a), but 9a was formed by the conversion of 8a on silica. The X-ray crystal structures of 6a and 9a have been determined. Crystals of 6a are monoclinic, space group P21/c, with unit-cell dimensions a = 12.106(14) A?, b = 9.490(10) A?, c = 16.780(7) A?, β = 97.61(7)°, V = 1911(3) A?3, Z = 4, final R = 0.055, and Rw = 0.040 for 2215 reflections with I > 3.0σ(7) and 245 parameters. Crystals of 9a are orthorhombic, space group P212121, with a = 9.819(1) A?, b = 11.928(1) A?, c = 17.338(1) A?, V = 2030.7(3) A?3, Z = 4, and final R = 0.044 for 1434 reflections with I > 2.5σ(7) and 254 parameters. The most important conclusion of this work is that isostructural FeRu- and Ru2-MAD-yl complexes show a large difference in reactivity, which can be rationalized by stronger π-coordination of the MAD-yl ligand to Fe as compared to Ru.
Behaviour of Polynuclear Ruthenium Carbonyl Carboxylates in the Presence of Hydrogen and/or Carbon Monoxide
Frediani, Piero,Bianchi, Mario,Salvini, Antonella,Piacenti, Franco
, p. 3663 - 3668 (2007/10/02)
The thermal behaviour in the temperature range 293-453 K of n3)2>, n3)2> and n3)2> in hydrocarbon solution, taken separately or in binary mixtures, with each other or with m>, under nitrogen or, alternatively, hydrogen, carbon monoxide, or their mixtures, has been monitored by i.r. spectroscopy under reaction conditions.A deficiency of ligands leads to the formation of larger clusters while their abundance in solution shifts the equilibria towards mononuclear complexes.Under carbonmonoxide the formation of ruthenium(0) complexes is obtained from the above compounds.The presence of hydrogen together with carbon monoxide seems to facilitate such evolution of the system probably through the formation of intermediate hydridic derivatives which however were not detected.
