in dichloromethane dissoln. of Co complex, filtration, addn of crushed AgClO4 (Co : Ag = 1 : 1.10), stirring (3.0 min), decantation, addn. of ether to soln. (pptn.); filtration, washing, second crop obtained on standing in refrigerator, recrystn. (CH2Cl2/ether), filtration, washing (ether); elem. anal.;