The rates of H₂ gas absorption (in dm³ mol⁻¹ s⁻¹) by alkenes catalysed by [RhCl(PPh₃)₃] in benzene at 25ºC are: hexene, 2910; cis-4-methyl-2-pentene, 990; cyclohexene, 3160; 1-methylcyclohexene, 60. Suggest the origin of the trends and identify the affected reaction step in the proposed mechanism (Fig. 22.18).

Figure 22.18.

Transcribed Image Text:

R Ph₂P CI Ph₂P CI R H H₂ Rh: Rh A PPh3 "H PPh3 PPh3 Me F PPh₂ PPh3 Ph₂P CI E LU Ph₂P, CI R H Rh H PPh3 B H Rh. PPh₂ PPh3 Me D Ph₂P, CI Ph₂P CI D. R PPh₂ Rh: с I. H Rh PPh3 D. R ..H Н PPh3