Question

In the Iso-electronic series of metal carbonyls, the C-O bond strength is expected to increase in the order:-
A. `[Mn(CO)_(6)]^(+)lt[Cr(CO)_(6)]lt[V(CO)_(6)]^(-)`
B. `[V(CO)_(6)]^(-)lt[Cr(CO)_(6)]lt[Me(CO)_(6)]^(+)`
C. `[V(CO)_(6)]^(-)lt[Mn(CO)_(6)]^(+)lt[Cr(CO)_(6)]`
D. `[Cr(CO)_(6)]lt[Mn(CO)_(6)]^(+)lt[V(CO)_(6)]^(-)`

Answer 1

Correct Answer - b
The more negative charge will give more electrons into `pi ^(**)` MO of CO . So the bond order decreases