Methanolic solutions of Co(OAc)2.2H2O (0.178 g, 1 mmol) and
Heptu (1.038 g, 2 mmol) were mixed together and stirred continuously
for 2 h. The resulting green solution was filtered off and kept
for crystalization. Dark green needle shaped crystals of 3 suitable
for X-ray analyses were obtained by slow evaporation of the above
solution over a period of 20 days.