Calixarenes oxyanions

Abstract. Several facets of calixarene chemistry have been investigated including the mechanism of their formation by the base-induced condensation of phenols and formaldehyde, procedures for introducing functional groups onto the upper rim and lower rim of calixarenes, the conformational behavior of calixarene oxyanions, the formation of complexes in aqueous and nonaqueous systems, and the application of calixarenes as catalysts. 

Key words. Calixarenes, calixarene oxyanions, conformation, complex formation, catalysis. 

The NMR spectra of the oxyanions generated by the action of BuLi on p-allylcalix[4]arene in DM SO suggest that the conformations of the mono- and tetra-anions are cone, while those of the di- and tri-anions are less clear " " (see ref. 1, pp. 124-126). However, X-ray crystal structures of the monosodium and dilithium salts of 4 , generated by the action of NaH or BuLi on the calixarene followed by treatment with MeOH, show both to be in the cone conformation in the solid state. "" ... 

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