Which from following is a weak field ligand?

Step-by-step solution

The strength of a ligand is determined by its position in the spectrochemical series, which orders ligands by their crystal field splitting ability. The comparative order of relevant ligands is: F ^- F ^- is a weak field ligand due to its position at the weaker end of the spectrochemical series, while the others exhibit stronger field characteristics. Carbonyl ( CO ) is particularly strong due to its -acceptor properties. The weakest field ligand among the options is C .