CoNH35NO2Cl2 and CoNH35ONOCl2 are related to each other as:

This type of isomerism occurs in complex compounds which ambidanate ligands like NO2−​,SCN−,CN−,S2​O32−​. These ligands have two donor atoms but at a time only one atom is directly linked to the central metal atom of the complex.[Co(NH3​)5​NO2​]Cl2​ and [Co(NH3​)5​ONO]Cl2​