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), RuHCl(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 1H NMR and IR spectra; the complex of RuHCl(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 × 10−5 mol (in 1 ml toluene), temperature 120 °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 °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 RuHCl(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 RuHCl(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.

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