116261-58-6Relevant articles and documents
Farrar, David H.,Gukathasan, R. R.,Lunniss, Julie A.
, p. 271 - 274 (1991)
Wavelegth-Dependent Primary Photoprocesses of Os3(CO)12 in Fluid Solution and in Rigid Alkane Glasses at Low Temperature: Spectroscopic Detection, Characterization, and Reactivity of Coordinatively Unsaturated Os3(CO)11
Bentsen, James G.,Wrighton, Mark S.
, p. 4518 - 4530 (1987)
Wavelegth-dependent photochemistry is reported for Os3(CO)12 in hydrocarbon solutions at 298 and 195 K and in rigid hydrocarbon glasses at 90 K.Near-UV and vis irradiation of 0.2 mM Os3(CO)12 at 298 k in alkane solutions containing 5 mM L yields mainly Os3(CO)11L (L = PPh3, P(OMe)3) as the initial photoproduct with a wavelegth-dependent quantum yield Φ436nm 366nm =0.017 +/- 0.001, and Φ313nm = 0.050 +/- 0.003 for L = PPh3, independent of the presence of added o.1 M tetrahydrofuran.Photosubstitution of PPh3 for CO is not affected by added 1 M CCl4, and the 366 nm quantum yield does not change on increasing the PPh3 concentration to 0.1 M, consistent with photodissociative loss of CO from an upper level excited state.Electronic spectral features for Os3(CO)12 become well-resolved in an alkane glass of 90 K; low-energy excitation into the first (382 nm: 10a1' -> 16e'; 1A1' -> 1E') or second (320 nm: 15e' -> 6a2'; 1A1' -> 1E') absorbtions for Os(CO)12 yields no net photochemistry in the 90 K alkane glass.However, excitation into the third electronic absorbtion (278 sh nm: 14e' -> 6a2'; 1A1' -> 1E') of 0.1 mM Os3(CO)12 yields loss of one CO as the only FTIR detected photoreaction to yield a single product, formulated as axially vacant Os3(CO)11 on the basis of FTIR and UV-vis spectral characterization and reaction chemistry.While the photogenerated Os(CO)11 reacts with 13CO at low temperature to give an axial-13CO-Os3(CO)11(13CO), UV irradiation of axial-13CO-Os3(CO)11(13CO) in a 90 K methylcyclohexane glass yields dissociative CO loss in a ratio of 12CO/13CO of greater than 28.These results suggest photodissociative loss of equatorial CO from Os3(CO)12, followed by rearrangement of equatorially vacant Os3(CO)11 to the axially vacant form.Photogenerated Os3(CO)11 reacts with two electron donor ligands to yield Os3(CO)11L complexes (L = N2,C2H4, PPh3, 1-pentene, 2-MeTHF) and with H2 to yield H2Os3(CO)11.The H2Os3(CO)11 complex has been detected by FTIR as an intermediate in the direct photoconversion (Φ366nm = 0.02) of Os3(CO)12 to H2Os3(CO)10 in H2-saturated alkane solutions at 298 K.Near-UV irradiation of H2Os3(CO)11 cleanly yields H2Os3(CO)10 and free CO at 298 or 90 K.Selective excitation into the second absorbtion of Os3(CO)12 at 90 K yields inefficient associative photosubstitution of strong ?-acceptors (C2H4, C5H10, 13CO) but not N2 or 2-MeTHF for CO.In fluid solutions, competitive photofragmentation is correlated with long wavelegth irradiation and with strong ?-acceptor ligands (CO, C2H4, not PPh3).
Control of the photochemistry of Ru3(CO)12 and Os3(CO)12 by variation of the solvent1
Leadbeater, Nicholas E.
, p. 211 - 216 (1999)
The synthetic potential of the photosubstitution of CO by two-electron donor ligands in M3(CO)12 [M=Ru, Os] has been investigated. When used as photolysis media, diethyl ether, ethyl acetate and acetonitrile act as photofragmentation quenchers allowing for the synthesis of photosubstitution products in high yield. UV photolysis of M3(CO)12 with added triphenylphosphine in these photolysis media leads to M3(CO)12-n(PPh3)n (n=1, 2 or 3). Prolonged photolysis with added tricyclohexylphosphine generates the highly sterically crowded complex M3(CO)9(PCy3)3. Photolysis with thiols, RSH (R=Et, Ph), leads to the thiolato complexes HM3(μ-SR)(CO)10, prolonged photolysis of which generates the corresponding sulphido cluster M3(μ3-S)(CO)10. Photolysis of M3(CO)12 in acetonitrile with no added ligand results in the generation of M3(CO)12-n(MeCN)n (n=1 or 2). This offers a route to these complexes without the need for the use of oxidising agents such as trimethylamine-N-oxide. Photolysis of an ethene-saturated diethyl ether or ethyl acetate solution of M3(CO)12 leads to no net photoreaction in the case of ruthenium, whereas, for osmium, the olefin complex Os(CO)4(η2-C2H4) is formed. This highlights the difference in the photosubstitution mechanism for Ru3(CO)12 and Os3(CO)12.
THE SYNTHESIS AND CHARACTERISATION OF NEW TRIOSMIUM AND TRIRUTHENIUM MAIN-GROUP METAL CLUSTERS M3(H)(CO)11(M'R3) AND Os3(H)(CO)10(CH3CN)(M'R3) (M=Os, Ru; M'=Ge, Sn; R, aryl, alkyl)
Burgess, K.,Guerin, C.,Johnson, B. F. G.,Lewis, J.
, p. C3 - C6 (1985)
Displacement of the (CH3CN) ligand from the compounds M3(CO)12-n-(MeCN)n (n=1 or 2) by organo-germanes and -stannanes provides a general method for the preparation of triosmium- and triruthenium-Main-Group metal clusters of the type M3(H)(CO)11(M'R3) and Os3(H)(CO)10(CH3CN)(M'R3) (M=Ru, Os; M'= Ge, Sn).
Efficient microwave syntheses of the compounds Os3(CO)11L, L = NCMe, py, PPh3
Jung, Jade Y.,Newton, Brittney S.,Tonkin, Michelle L.,Powell, Cynthia B.,Powell, Gregory L.
, p. 3526 - 3528 (2009)
The results of simple microwave-assisted ligand substitution reactions of Os3(CO)12 are reported. In a remarkably short period of time, the labile complex Os3(CO)11(NCMe) is prepared in high yield without the ne
Heterosite effects in novel heteronuclear clusters [Os 2Ru(CO)11(PPh3)] and [Os2Ru(CO) 10(2-acetylpyridine-N-isopropylimine)]
Vergeer, Frank W.,Lutz, Martin,Spek, Anthony L.,Calhorda, Maria J.,Stufkens, Derk J.,Hartl, Frantisek
, p. 2206 - 2222 (2007/10/03)
A new synthetic route towards the mixed-metal cluster [Os 2Ru(CO)12] is described together with the syntheses of its PPh3 and iPr-AcPy (iPr-AcPy = 2-acetylpyridine-N-isopropylimine) derivatives. The molecular structures of the novel clusters [Os 2Ru(CO)11(PPh3)] and [Os2Ru(CO) 10(iPr-AcPy)] were determined on the basis of crystalline solid solutions of the Os2Ru and corresponding Os3 species. The structures reveal that coordination of the Lewis bases occurs exclusively at the ruthenium site of [Os2Ru(CO)12], which is in agreement with density functional theory (DFT) calculations on several structural isomers of these compounds. According to the time-dependent DFT results, the lowest optically accessible excited state of [Os 2Ru(CO)10(iPr-AcPy)] has a prevailing σ(Ru-Os2)-π*(iPr-AcPy) character, with a partial σσ* (Ru-Os2) contribution. In weakly coordinating 2-chlorobutane, the excited state has a lifetime τ = 10.4 ± 1.2 ps and produces biradicals considerably faster than observed for [Os 3(CO)10(iPr-AcPy) (τ = 25.3 ± 0.7 ps). In coordinating acetonitrile, the excited state of [Os2Ru(CO) 10(iPr-AcPy)] decays mono-exponentially with a lifetime τ = 2.1 ± 0.2 ps. In contrast to [Os3(CO)10(iPr-AcPy)] that forms biradicals as the main primary photoproduct even in strongly coordinating solvents, zwitterion formation from the solvated lowest excited state is observed for the heterometallic cluster. This is concluded from time-resolved absorption studies in the microsecond time domain. Due to the lower tendency of the coordinatively unsaturated +Ru(CO) 2-(iPr-AcPy-/0) moiety to bind a Lewis base, the heteronuclear biradical and zwitterionic photoproducts live significantly shorter than their triosmium counterparts. The influence of the weaker Os2-Ru(iPr-AcPy) bond on the redox reactivity is clearly reflected in very reactive radical anions formed upon electrochemical reduction of [Os 2Ru(CO)10(iPr-AcPy)]. The dimer [-Os(CO) 4-Os(CO)4-Ru(CO)2(iPr-AcPy)]2 2- is the only IR-detectable intermediate reduction product. The dinuclear complex [Os2(CO)8]2- and insoluble [Ru(CO)2(iPr-AcPy)]n are the ultimate reduction products, proving fragmentation of the Os2Ru core. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
