Question

Correct sequence of $CO$ bond order in given compounds is

(P) $\mathrm{Fe}(\mathrm{CO}{)}_5(\mathrm{Q})\mathrm{CO}(\mathrm{R}){\mathrm{H}}_3\mathrm{B}\leftarrow \mathrm{CO}(\mathrm{S}){\left[\mathrm{Mn}(\mathrm{CO}{)}_5\right]}^{-}$

• A. $P>R>S>Q$
• B. $S>P>R>Q$
• C. $Q>S>P>R$
• D. $R>Q>P>S$

Answer 1

Answer: (D)

$\left(Q\right)$

$:\stackrel{-}{C}\equiv \stackrel{+}{O}:B.O.=3$

$\left(P\right)\&\left(S\right)$

$M\rightleftarrows C=OB.O.=2$

$\left(R\right)$

$H_3\stackrel{-}{B}\leftarrow C\equiv \stackrel{+}{O}B.O.=3$