A synthetic and structural investigation of the role of hydrogen bonding in clathrate formation

Abstract

A study of molecules related to Dianin's compound (I) in which the hydroxy-function is replaced by another group capable of forming hydrogen bonds is described. The amine (II) crystallises with spontaneous resolution, without incorporation of solvent. The thiol (III) shows an interesting duality of behaviour, crystallising unsolvated with spontaneous resolution from cyclohexane, but forming a true clathrate with carbon tetrachloride. This clathrate crystallises in the trigonal space group R , with a= 27.063, c= 12.074 Å, with 18 host and 6 guest molecules in the unit cell. The structure was solved by direct methods, and refined to a final R value of 10.4% for 1 475 independent diffractometer data. Near planar hexagons of sulphur atoms, linked by SH ⋯ S hydrogen bonds, form the top and bottom of each closed cage in the clathrate structure.