Tetraaminecopper(II) ion : [Cu(NH3​)4​]2+Tetracyanonickelate(II) ion : [Ni(CN)4​]2−Trioxalatocobaltate(III) ion : [Co(C2​O4​)3​]3−Triamminetrinitrocobalt(III) : [Co(NH3​)3​(NO2​)3​]Tetraaminecopper(II) ion is a cationic sphere complex.