Conformation distorted cone

The conformations of the parent calix[6]arenes have been variously described as distorted cone [6 - ], double partial cone and 6 ° winged... 

Extending the macrocycle ring to six-membered ring fives more flexibility to the calix[6]arene molecule compared to three- four- and five-membered calixarenes. For calix[6]arenes eight main (basic) conformations are defined [41] distorted cone, compressed cone, pinched cone, double partial cone, winged, 1,2,3-altemate, 1,3,5-altemate and distorted 1,2,3-altemate. Other conformations are also observed... 

The structure of 3a has been elucidated by single-crystal X-ray analysis. Compound 3a adopts a relatively distorted cone conformation in the solid state, creating... 

The preferred conformation of resorcarenes is different for the various diastereomers. The rccc isomer assumes a cone crown) conformation with an axial orientation of the residues R, which can be distorted to a so-called boat conformation where two opposite rings are more or less parallel, while the remaining two are bent away from the cavity becoming nearly coplanar. The cone conformation with an all-equatorial orientation of R was never observed. The rctt isomer is always found in a chair conformation, in which... 

The molecular capsules are sealed electrostatically by means of interactions between anionic SO3 groups and Ba cations. The p-sulfonatocalix[7]arene adopts a distorted double-cone pinched conformation. 

Calix[8]arenes may adopt 16 main (basic) conformations[41] and numerous intermediate or distorted conformations related to the main ones. There are two extreme conformations the double cone or inverted double cone conformation which may be characterized as a compact one and mimics two joined together in parallel or antiparallel cones of calix[4]arenes and, at the other end, there is an extended nearly planar circular conformation which may be called rosette or pleated loop . This extreme conformations are exemplified by these found for para-sulphonatocalix[8] arene (Fig. 38.26). 

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