The fluxional behaviour of η6(bicyclo[6.2.0]deca-2,4,6-triene) hexacarbonyl diruthenium (Ru-Ru) by 1H and 13C NMR techniques

Abstract The variable temperature 1 H NMR spectra of [Ru 2 (CO) 6 η 6 -C 10 H 12 )] (C 10 H 12 = bicyclo [6.2.0]-deca-2,4,6-triene) shows that this molecule undergoes the fluxional behaviour previously reported for [M 2 (CO) 6 (η 6 -polyolefin)] complexes (M = Fe, Ru) which have in the solid an asymmetric skew-type structure. The use of 13 C NMR techniques, employed for the first time for a diruthenium complex of the above type, allows a comparison of the mechanism of the fluxional process with that of the diiron analog. Although the observed line shape changes of the carbonyl resonances in the two complexes are somewhat different the process are basically the same. In the case of the dirut…

Selective, homogeneous hydrogenation of cycloheptatriene to cycloheptene catalyzed by (η4-cycloocta-1,5-diene)(η6-cyclohepta-1,3,5-triene)ruthenium(0)

Abstract In the presence of small amounts of [Ru(η 4 -COD)](η 6 -C 8 H 10 )] (1), cycloheptatriene is hydrogenated to cycloheptene, under one atmosphere of hydrogen at room temperature in homogeneous phase. The formation of a small amount of cyclooctene and the existence of an induction period, which do not occur when [Ru(η 4 -COD)(η 6 -C 7 H 8 )] (2) is used as the catalyst, suggest that 2 is the real catalyst. The selectivity of this hydrogenation is 100% in n-hexane as solvent, 99.5% in THF, and low in ethanol. Conversion is quantitative in THF and ethanol, but not more than 65% in n-hexane. In the presence of 1 or 2, cycloheptene is rapidly hydrogenated to cycloheptane in THF and ethano…

Surface and Bulk Changes of a Pt 1%/Ce0.6Zr0.4O2 Catalyst During CO Oxidation in the Absence of O2

He-I and He-II excited photoelectron spectra of cyclohepttatrienetricarbonyl complexes of group via metals

Abstract Photoelectron spectra of Group VIA metal complexes M(CO) 3 (η 6 -C 7 H 8 ) have been assigned using experimental criteria along with quantum-mechanical calculations. A general agreement between computed and measured ionization energies has been found for molecular orbitas mainly ligand in character. Similar correlations do not hold for the highest orbitals, mainly metal d based. The energies associated with ionization processes are, in this case, largely dominated by the relaxation terms. The variations of intensities of these bands on changing the energy of ionizing radiation were of crucial significance in the assignment

1H and 13C NMR investigation of the fluxional behavior of η6-(bicyclo[6.1.0]Nona-2,4,6-triene)hexacarbonyldiiron- (FeFe)

Abstract The variable temperature 1 H and 13 C NMR spectra of (C 9 H 10 )Fe 2 (CO) 6 have been recorded. The molecule is fluxional. The high temperature spectra indicate an apparent plane of symmetry bisecting the bound organic ligand, whereas the low temperature limiting spectra are entirely consistent with the asymmetric skew-type structure found in the crystal. Thus the molecule is also properly described in solution as μ-(2-σ,6,7-η:35-η-bicyclo[6.1.0]nonatriene)hexacarbonyldiiron(FeFe). Based on the observed line shape changes of the carbonyl resonances between −140 and −110°C, it is shown that the twitching and not the gliding process is responsible for the relative movement of the F…