Guest volumes

The structures of the acetic acidS0) and of the propionic acid71 inclusions of 26 (Fig. 20, type III) are isomorphous to each other. The increased guest volume with respect to formic acid yields 1 1 stoichiometry, with no H-bonds between host and guest molecules in either case. The tunnel where the dimers of guests are situated (see Fig. 32 a) is functionally the same as in the case of the self-dimerized pairs of the formic acid guests. 

Templating molecule Template ratio Guest volume (A3) Packing coefficient (%)... 

Guest volumes and packing coefficients83,84 (PC = (guest volume/host volume) x 100) were computed with Spartane1 software. 

Guest Volume (A )/ Structure Pj (MPa) at 273 K Maximum length (A) Lattice Constant (A) Crystal References at 173 K ... 

Figure 19 Visualization of adaptability of the inner phase of hemicareerand 6 to different guest dimensions through untwisting. From left to right hemieareeplexes 6 benzene, 6 -xylene, and 6 l,4-diiodobenzene. Hemicareerands and cavities were modeled with the program Swiss-PdbViewer. The inner phase and guest volumes as well as the spaee oeeupancy in the inner phase are given for each hemicarceplex.

Analysis of the variation in the torsion angles which control the conformation of the phenyl rings of the host and the concomitant volume of the space available for the enclathrated 2-butylamine guests shows that enhanced enantiomeric selectivity arises from smaller guest volumes. 

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