What is the donor atom of [CO(NH3)5 (OCN)]2+ and [CO(NH3)5 (CNO)]2+

Dear student,ligand is SCN and NCS i.e thiocyanato and isothiocyanato respectively and not OCN and NCO.In complex with NCS-,,ligand is bonded to the metal through nitrogen (M-NCS), and in SCN- through sulphur (M-SCN) in complexes formed by these isomers.