Springer Online Journal Archives 1860-2000
Chemistry and Pharmacology
Abstract The crystal structures of two compounds belonging to the isomorphous series of clathrate inclusion complexes of tetraphenylene, 2C24H16·X (with X=benzene (I) and X-cyclohexane (II), were solved. For (I),a=10.0691(1),c=18.431(5) Å, space groupP42/n,Z=2; (II) has a very similar cell. Crystal structure analyses (Nicolet R3m four-circle diffractometer, graphite-monochromated MoKα; (I) 926 reflections,R F =12.8%; (II) 1180 reflections,R F =10%) showed that the tetraphenylene molecules use crystallographicC 2 symmetry in the construction of a nearly spherical cavity of point symmetry 4 located about 1/4 1/4 1/4. The geometry of the tetraphenylene molecule agrees well with that reported earlier for the crystals of neat tetraphenylene. The enclosed benzene and cyclohexane guests are necessarily disordered. Thedisorder found for the cyclohexane guest is consistent with its expectedchair conformation. Analysis of the cell dimensions of a number of complexes shows that the tetraphenylene framework adjusts itself according to the steric requirements of the guests.
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