Q73 · CSIR-NET Chemistry, December 2015

Paper: CSIR-NET December 2015 · Subject: Inorganic Chemistry · Chapter: Organometallic Compounds · Topic: Organometallic Compounds – General · Marks: 2 · Difficulty: Easy

For the reaction of $\left[\mathrm{Fe}\left(\eta^{5}-\mathrm{C}_{5} \mathrm{H}_{5}\right)\left(\mathrm{CH}_{3}\right)(\mathrm{CO})_{2}\right]$ with $\mathrm{PMe}_{3}$, the main intermediate is
(a)$\left[\mathrm{Fe}\left(\eta^{5}-\mathrm{C}_{5} \mathrm{H}_{5}\right)\left(\mathrm{CH}_{3}\right)(\mathrm{CO})_{2}\left(\mathrm{PMe}_{3}\right)\right]$
(b)$\left[\mathrm{Fe}\left(\eta^{5}-\mathrm{C}_{5} \mathrm{H}_{5}\right)\left(\mathrm{COCH}_{3}\right)(\mathrm{CO})\right]$
(c)$\left[\mathrm{Fe}\left(\eta^{3}-\mathrm{C}_{5} \mathrm{H}_{5}\right)(\mathrm{CH}_{3})(\mathrm{CO})_{2}\right]$
(d)$\left[\mathrm{Fe}\left(\eta^{3}-\mathrm{C}_{5} \mathrm{H}_{5}\right)\left(\mathrm{COCH}_{3}\right)(\mathrm{CO})\left(\mathrm{PMe}_{3}\right)\right]$
Answer
Answer: B ✓ checked by 4AB · confidence high
Explanation
The methyl migrates onto CO first, giving the 16-electron acetyl intermediate [CpFe(COCH₃)(CO)], which PMe₃ then traps.

Study loop for Organometallic Compounds

1. Practise the PYQsPrevious-year questions, with answers

· Browse this chapter in the app