Unprecedented sodium–oxygen clusters in the solid-state structure of trisodium hydrogentetravalproate monohydrate: A model for the physiological activity of the anticonvulsant drug Epilim®

The first crystal structure determination of one of the solid forms of sodium valproate revealed that the crystal is a 3:1 solvate of sodium valproate and valproic acid. The anion symmetry-directed formation of stable sodium–oxygen clusters protected by alkyl layer which can act as lipophilic micelles may be important for understanding the strong anticonvulsant activity of the valproate ion.