Question

The correct sequence of $CO$ bond length in the given compound is:
(I) $Fe\left(CO\right)_{5}$
(II) $CO$
(III) $H_{3}B\leftarrow CO$
(IV) $\left[Mn \left(CO\right)_{5}\right]$

• A. II > IV > III > I
• B. II > III > I > IV
• C. III > I > IV > II
• D. IV > I > II > III

Answer 1

Answer: (D)

As the oxidation state of metal decrease the extant of back bonding by $CO$ increases.