Hexane → 2,3-Dimethyl-1-butene

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Ta(C5Me5)(propylene)Cl2 (0.11 g, 0.25 mmol) was dissolved in 2.5 ml of hexane in a 20 ml glass pressure bottle containing a small teflon-coated magnetic stir bar. A pressure head equipped with a rubber system for sampling the mixture was clamped to the glass vessel and the vessel was pressurized to 40 psi with propylene and immersed in a stirred bath maintained at 32° C. Samples were withdrawn by syringe at regular intervals, quenched with gaseous oxygen, and analyzed by gas chromatography. 2,3-dimethyl-1-butene and 2-methyl-1-pentene formed steadily in a 98:2 ratio at a rate of 0.0014 M min-1 or k1 =0.014 min-1 since the catalyst concentration is 0.1 M. At 40° k1 =0.039 min-1 which amounts to about 1 turnover per hour per Ta. The rate increases markedly at higher temperatures (ΔH++ =19±1 kcal mol-1, ΔS ++ =14±3 eu).

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