What are negative ligands?
Any negatively charged species that is able to donate its lone pair to the metal is called a negative ligand. For example, Cl- , Br-, SO4-2, C2O4-2. The name of the ligand will end with O (i.e. sulphate will become sulphato, nitrite will become nitrito etc.)
NEGATIVE LIGANDS. Nitrosyl (nitrosyl), NO− (double-bonded, bonds to metal in a bent configuration) Cyanide (cyano), −CN. Chloride (chloro), Cl− Thiocyanate (thiocyanato), S−C≡N