Most of the metal carbonyls obey inert gas rule which states the the compounds in which the central metal atom appears to have attained the configuration of a noble gas either by the sharing or by the transfer of electrons tend to be more stable
Which of the following has highest `C-O` bond length ?
(a) `[mn(CO)_(6)]^(o+)`
(b) `[Co(CO)_(4)]^(Θ)`
(c) `[Fe(CO)_(4))]^(2-)`
(d) `[Ni(CO)_(4)]` .

Answer

C