Which of the following statement is correct with respect to the metal carbonyl of Ist transition series ?

Options

A. As `M-Cpi` bonding increases, the C-O bond length increases .
B. As positive charge on the central metal atom increases, the C-O bond length increases.
C. As electron density on the central metal atom increases, the C-O bond length increases.
D. (a) and (c ) both

Answer

D

Explanation

As M-C bond becomes stronger, C-O B.L.`uarr`. M-C bond becomes stronger when back bonding from metal to C occurs, which is possible when electron density on metal is high