Coordination Compounds 2 Question 37
39. Among the following metal carbonyls, the $C-O$ bond order is lowest in
(a) $\left[Mn(CO) _6\right]^{+}$
(b) $\left[Fe(CO) _5\right]$
(c) $\left[Cr(CO) _6\right]$
(d) $\left[V(CO) _6\right]^{-}$
$(2007,3 M)$
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Answer:
Correct Answer: 39. (b)
Solution:
- Greater the extent of $d \pi-p \pi$ back bonding, smaller will be the bond order of $CO$ bond in metal carbonyls. $\operatorname{In} Fe(CO) _5$, there is maximum number of valence shell electrons ( $d$-electrons), greatest chances of $p \pi-d \pi$ back bonding, lowest bond order of $CO$ bond.
BETA
