Dipole Moments of Calixarenes

Rather little attention has been given to the measurement and calculation of dipole moments of calixarenes. The most comprehensive experimental study includes data on nine calix[4]arenes with examples of each of the four up-down conformations, as shown in Table 3.2. As anticipated from simple inspection of molecular models, the sequence of decreasing dipole moment is cone partial cone 1,2-alternate 1,3-alternate. A computational study affirms the sequence of decreasing dipole moment as cone partial cone 1,2-alternate 1,3-alternate but yields a value of only 0.46 D for 4 and values of 1.46, 

Elguero, J. Reel. Trav. Chim. Pays-Bas 1993, 112, 367. 

Iwamoto, K. Ikeda, A. Araki, K. Harada, T. Shinkai, S. Tetrahedron Lett. 1993, 49, 9937. 

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