${\left[ {V\,{{\left( {CN} \right)}_6}} \right]^{4 - }}$ , ${\left[ {Fe\,{{\left( {CN} \right)}_6}} \right]^{4 - }}$ , ${\left[ {Ru\,{{\left( {N{H_3}} \right)}_6}} \right]^{3 + }}$ , અને ${\left[ {Cr\,{{\left( {N{H_3}} \right)}_6}} \right]^{2 + }}$