Hexaquocobalt II bis-p-toluenesulfonate

To cobalt powder (4.23 g, 71.8 mmol) in a 250-mL, round-bottomed flask equipped with a reflux condenser is added p-toluenesulfonic acid monohydrate (23.26 g, 122 mmol) and water (20 mL). The mixture is heated to reflux for 5 h. The resulting reddish-pink solution is filtered whUe hot through Celite, and the filter cake is washed with water (3 x 10 mL). The filtrate is cooled to room temperature, and pale orange blocks form after 2 h. The crystals are collected by filtration and dried overnight under vacuum at room temperature. A second crop of crystals are obtained by concentration and cooUng of the mother liquor. Yield 16.75 g (53.8%). 

Pale orange [Co(OH2)6](OTs)2 can be stored indefinitely at room temperature under an inert atmosphere. It is soluble in methanol and water. 

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