Computational studies of calix[4]arene homologs: influence of 5,11,17,23- and 25,26,27,28-substituents on the relative stability of four conformers
1993; Elsevier BV; Volume: 49; Issue: 27 Linguagem: Inglês
10.1016/s0040-4020(01)87180-5
ISSN1464-5416
AutoresTakaaki Harada, Jerzy M. Rudziński, Eiji Ōsawa, Seiji Shinkai,
Tópico(s)Synthesis and Properties of Aromatic Compounds
ResumoThe effects of 5,11,17,23- and 25,26,27,28-substitutents on the relative stability of four conformers of calix[4]arene are discussed on the basis of a computational method using molecular mechanics (MM3) calculations. It is shown that a substituent in the lower rim site has a decisive role in the determination of the stability order among four conformers of calix[4]arene, while a substituent in the upper rim site only slightly affects the energy differences. It is also shown that in [14]metacyclophanes with no substituent in the lower rim the structure of 1,2-alternate conformers is very different from the typical 1,2-alternate structure common to calix[4]arenes.
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