12375-04-1Relevant academic research and scientific papers
Methylidyne-alkyne coupling on triruthenium clusters and hydrogenation of cluster-bound 1,3-dimetalloallyl units. A new model for Fischer-Tropsch chain growth
Beanan, Lawrence R.,Keister, Jerome B.
, p. 1713 - 1721 (2008/10/08)
Alkylidyne-alkyne coupling occurs upon reaction of H3Ru3(μ3-CX)(CO)9 (X = OMe, Me, Ph, or CH2CH2CMe3) at 25 °C or HRu3(μ-CX)(CO)10 (X = OMe) at 60 °C with alkynes R1C2R2, forming 1,3-dimetalloallyl clusters HRu3(μ3-η3-XCCRCR)(CO)9 (X = OMe, (R1, R2) = (H, H), (Me, Me), (Ph, Ph), (H, Ph), (H, CMe3), (H, n-Bu), (H, CO2Me), (Ph, CO2Me), (H, OEt); X = Ph, (R1, R2) = (Ph, Ph); X = Me, (R1, R2) = (Me, Me); X = CH2CH2CMe3, (R1, R2) = (Ph, Ph)) in yields of 15-90%. In an analogous fashion, HOs3(μ-COMe)(CO)10 and PhC2Ph yield HOs3(μ3-η3-MeOCCPhCPh)(CO)9. One equivalent of the appropriate cis-alkene is formed from reduction of alkyne by H3Ru3(μ3-CX)(CO)9. With unsymmetrical alkynes the relative amounts of the two possible regioisomers depend upon the alkyne substituents. Coupling from either H3R3(μ3-COMe)(CO)9 or HRu3(μ-COMe)(CO)10 forms HRu3(μ3-η3-MeOCCR1CR 2)(CO)9 in the relative amounts (R1, R2) = (H, Ph)/(Ph, H), 3:1, (H, n-Bu)/(n-Bu, H), 2:1, (H, CMe3,)/(CMe3, H), 20:1, (H, CO2Me)/(CO2Me, H), 2:1, (H, OEt)/(OEt, H), 1:0, (Me, C7-H15, Me), 3:1, and (CO2Me, Ph)/(Ph, CO2Me), 2:1. Hydrogenation (90 °C, 1-4 atm) of HRu3(μ3-η3MeOCCR1CR 2)(CO)9 ((R1, R2) = (H, H), (H, CMe3), (Me, Me), (Ph, Ph), (H, OEt), (H, Ph), (H, n-Bu), (n-Bu, H), (H, CO2Me)) produces in each case the corresponding H3Ru3(μ3CCHR1CH2R 2)(CO)9 in yields of 6-43%; also formed are substantial quantities of H4Ru4(CO)12. Hydrogenation of DRu3(μ3-η3-MeOCCHCCMe 3)(CO)9 produces exclusively H3Ru3(μ3-CCH2CHDCMe 3)(CO)9. This alkylidyne-alkyne coupling and subsequent hydrogenation to form an alkylidyne of longer carbon chain length suggests a mechanism to account for 2-methylated hydrocarbon products in the Fischer-Tropsch reaction.
SYNTHESIS OF HYDRIDOTRIOSMIUM COMPLEXES CONTAINING ISOMERIC μ-CARBOXAMIDO, , AND μ-IMINYL, , GROUPS. CRYSTAL AND MOLECULAR STRUCTURE OF Os3(CO)10, R' = C(=O)NHCH3
Lin, Ying-Chih,Mayr, Andreas,Knobler, Carolyn B.,Kaesz, Herbert D.
, p. 207 - 230 (2007/10/02)
Primary or secondary aliphatic amines are observed to react with Os3(CO)12 in excess amine or other polar solvents at temperatures in the range -10 to 25 deg C.One mole of CO is evolved and a μ(O,C)-carboxamido complex (1) is isolated in high yield: Os3(CO)10 (1a, R = Me, R' = H; 1b, R = R' = Me; 1c, R = n-Pr, R' = H, 1d, R = n-Bu, R' = H; 1e, R = Et, R' = H).The 1H NMR spectrum of 1e indicates the existence of two isomers due to the restricted rotation around the C-N bond of the μ-carboxamido group.Reaction of methyl or ethyl isocyanate with Os32(CO)10 at room temperature under N2 gives three principal products: a μ(O,N)-formamido complex, Os3(CO)10 (2), the μ(O,C)-carboxamido complex, 1, and a μ(C,N)-iminylurethane complex, Os3(CO)10, (4, R' = C(=O)NHR).Product 1 in this reaction arises from isomerization of an intermediate μ(C,N)-hydroxyiminyl complex, Os3(μ-H,μ-C(OH)=NR(CO)10 (3).This complex is isolated upon initial chromatography of the reaction mixture.For the isomerization of 3 to 1, t1/2 17.5 d in CDCl3 solution, Ea 92 kJ/mol.Spectroscopic data indicate that 3 is a mixture of tautomers in ratio of 19/1 in CDCl3: Os3(CO)10 (3-enol) and Os3(CO)10 (3-keto). The structure of 4 has been determined at -158 deg C using a Syntex P computer-automated diffractometer and graphite-monochromatized Mo-Kα radiation.Some 2936 unique reflections with I >3?(I) were used in the refinement to give final discrepancy indices of R = 0.030 and Rw = 0.037.The complex crystallizes in the monoclinic space group P21/c in a cell having the dimensions of a 13.413(3) Angstroem, b 16.712(3) Angstroem, c 9.400(3) Angstroem, and β 95.01(2) deg.The calculated density is 3.06 g cm-3.
