SOLID-STATE AND INCLUSION PROPERTIES OF HYDROGEN-BONDED 1,3-CYCLOHEXANEDIONE CYCLAMERS

During crystallization 1,3-cyclohexanedione self assembles into either hydrogen-bonded chains or hexameric rings depending on the solvent conditions. The hexameric rings, called cyclamers, are the subject of this paper. These unusual structures occlude benzene as a guest molecule. The structural and crystal chemical properties of these host-guest compounds are explored here with the use of crystal growth studies, X-ray powder patterns, and thermal analysis. The crystal structure of the benzene cyclamer of 5-methyl-1,3-cyclohexanedione is reported (hexagonal, a =b = 19.19(2)Å, c = 10.545(9)Å, R3, Z = 18, V = 3362(6)Å3; 717 unique reflections, R = 0.062). An analysis of the stereochemical implications of cyclic directionality in these cyclamers is also discussed. © 1990 Kluwer Academic Publishers.