Olefins isomerization by hydride-complexes of ruthenium

Several complexes containing the Ru-H bond were synthesized according to previous reports: RuH(NO)(PPh3)(3)(I) (1), RuHCI(PPh3)(3)(S)(II) (2), RuHCl(CO)(PPh3)(3)(II) (3), RuH(CH3COO)(PPh3)(3)(II) (4) and RuH2(CO)(PPh3)(3)(II) (5), and characterized by H-1 NMR and IR spectra; the complex of RuHCI(PPh3)3(S) was screened for further investigation on the basis of activity and life-operating on isomerization of 1-hexene and 1-octadecene in temperature; the influence of temperature, reaction time and catalyst concentration on 1-hexene isomerization by RuHCl(PPh3)(3)(S) was carefully studied: 1-hexene was converted into other two isomers of 19.39% 2-hexene and 78.16% 3-hexene on the condition of catalyst 2 x 10(-5) mol (in 1 ml toluene), temperature 120 degrees C, time 30 min, 1-hexene 4 ml; while the performance on 1-octadecene isomerization by RuHCl(PPh3)(3)(S) presented high activity, thermal stability and the solvent-free system: at 180 degrees C the equilibrium conversion of 1-octadecene reached above 94.6% with the condition of the 1:200 (mol) ratio of catalyst to substrate; and the distinct differences were presented on the isomerization by RuHCI(PPh3)(3)(S) for 1-hexene and 1-octadecene in reaction temperature, solvent, intermediate. The evidence on isomerization of 1-hexene and 1-octadcene by RuHCI(PPh3)(3)(S) was provided to recognize the specifically isomerization process: the catalytic property was closely relation with coordination circumference of the centre metal, ligand property and substrate structure, and the mechanism was carefully studied on 2 as well. (c) 2006 Elsevier B.V. All rights reserved.