Compare [V(CO)6]^- with Cr(CO)6 (same size, 18 electrons each). Which statements are correct?

The C-O bond is longer in [V(CO)6]^-

The M-C bond is shorter in [V(CO)6]^-

The C-O bond is longer in [V(CO)6]^-

The M-C bond is shorter in [V(CO)6]^-

JEE Advanced levelOne or more correct optionsDifficulty 3 of 3cc217

Compare $[V (CO) X_{6}] X^{-}$ with $Cr (CO) X_{6}$ (same size, 18 electrons each). Which statements are correct?

The anionic vanadium centre is more electron-rich, so back-donation is greater. This lengthens C-O (A) and shortens M-C (B), and lowers

ν (CO)

, so (C) is false. Neither is stated to be paramagnetic: both are 18-electron diamagnetic species, so (D) is false. Correct: A and B.