Co(NO₃)₂.6H₂O;
NaH(CO₃);
H₂O₂ (30%)

NaH(CO₃) (42.185 g, 0.502 mol) was added to water (50 ml). The solution was stirred and placed in an ice bath. A solution of Co(NO₃)₂.6H₂O (29.118 g, 0.100 mol), water (50 ml), and H₂O₂ (30%, 10 ml) was added dropwise to the ice cold slurry. On addition of the solution, the reaction mixture turned green. The mixture was kept at 0 °C for a further 1½ hours, whilst being continuously stirred. The green product was filtered, washed with cold water (3 x 10 ml), ethanol (2 x 10 ml), and diethyl ether (2 x 10 ml). The dark green precipitate was left to dry overnight under dynamic vacuum. Yield 31.9 g, 88%

IR(cm^-1): 3238 (O-H), 1451 (C=O), 1328 (C=O). CHN % found (calculated for C₃H₆CoNa₃O₁₂): C 10.09 (9.95), H 1.29 (1.67)

A.Damiamoglou et al. A New Reference Material for UV-visible Circular Dichroism Spectroscopy, Chirality, 2008 H.F.Bauer and W.C.Drinkard, J. Am. Chem. Soc., 1960, 82, 5031