The general procedure for the synthesis of (S,S)-N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine cobalt(II) from cobalt acetate and 1,2-cyclohexylamine bis(3,5- butyl sulphate) is as follows: with reference to Example 1, (R,R)-N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine (10.9 g. 20.0 mmol) was dissolved in dichloromethane (80 mL). The solution was slowly added to a methanol solution of cobalt tetrahydrate acetate (5.98 g, 24.0 mmol) (80 mL) and the reaction was stirred at room temperature for 15 min. A red solid gradually precipitated during the reaction. The reaction mixture was then continued to be stirred at 0 °C for 30 min to promote complete precipitation. The red solid was collected by filtration and the target product Co(L3) (11.6 g, red solid) was obtained after drying in 96% yield.
