Cyclohexanedione cyclamer

Etter, M. C., Urbanczyklipkowska, Z., Jahn, D. A., Frye, J. S., Solid-state structural characterization of 1,3-cyclohex-anedione and of a 6-1 cyclohexanedione-benzene cyclamer, a novel host guest species. J. Am. Chem. Soc. 1986, 108, 5871-5876. 

Fig. 1 Etter s example of crystal engineering with O—H-. O hydrogen bonds (a) a space-filling representation of the chain of O—H-. Obonded 1.3-cyclohexanedione molecules,crystallized from THF and (b) the cyclamer formed by 1.3-cyclohexanedione with benzene—note how the benzene molecule is surrounded by six neutral molecules linked by O—H- -O interactions.

---