dihydrogen peroxide in hydrogenchloride addn. of concd. HCl-soln. and NaClO4 to an aq. soln. of ethylenediamine monohydrate, CoCl2*6H2O and 3percent H2O2-soln.; heating on a water-bath; crystallization on a water-bath;; washing with HClO4-containing H2O; drying at 105°C;;

perchloric acid; dihydrogen peroxide addn. of H2NC2H4NH2 and H2O2 to an ice-cooled Co(II) soln., heating themixt. to 60-70°c for 10 min, addn. of HClO4 and cooling in an ice bath; filtering the green solid, washing with i-PrOH and air drying, elem. anal.;

in not given recrystn. of of complex from NaClO4 soln.; elem. anal.;

in water pptn. on perchlorate addn.; dissolving in aq. HClO4 (pH = 2), filtration, concn. (vac., low temp.); elem. anal.;