If in the mixed carbonyl the other ligand is also `pi` acceptor it would compete with the ligand `CO` for gaining the metal `d_(pi)` electron charge The higher is the extent of back donation in `CO` , the lesser will be the stretching vibration frequency for `C-O` bond If `PP_(3)` is better pi-acceptor than `CO` then answer the following
Select the correct order of `C-O` bond length in the following molecules .
(I) `[Mo(CO)_(3)(PF_(3))_(3)]` (II) `[Mo(CO)_(3)(PCI_(3))_(3)]`
(III) `[Mo(CO)_(3)(P(Me)_(3))]`
(a) `IgtIIgtIII`
(b) `IIIgtIgtII`
(c) `IIgtIIIgtI`
(d) `IltIIltIII`

Answer

A