An efficient catalyst for hdrogenation of alkenes is $\left[\mathrm{Rh}\left(\mathrm{PPh}_{3}\right)_{3} \mathrm{Cl}\right]$. However, $\left[\operatorname{Ir}\left(\mathrm{PPh}_{3}\right)_{3} \mathrm{Cl}\right]$ does not catalyze this reaction, because
(a)$\mathrm{PPh}_{3}$ binds stronger to Ir than to Rh
(b)Cl binds stronger to Ir than to Rh
(c)$\mathrm{PPh}_{3}$ binds stronger to Rh than to Ir
(d)Cl binds stronger to Rh than to Ir
Answer
Answer: A ✓ checked by 4AB · confidence high
Explanation
PPh₃ binds more strongly to the 5d metal Ir, so it does not dissociate to open a coordination site (a).