The chemical formula of nitropentammine chromium (III) chloride is [Cr(NH3)5‌NO2]Cl2 It can exist in following two structures [Cr(NH3)5‌NO2]Cl2 and nitropentammine chromium (III) chloride [Cr(NH3)5‌ONO]Cl2 Nitropentammine chromium (III) chloride Therefore the type of isomerism found in this compound is linkage isomerism as nitro group is linked through N as −NO2 or through O as −ONO.