New Syntheses and Physical Properties of p-Alkylcalixarenes

Article abstract of DOI:10.1246/bcsj.64.381

Calixarenes (n=4, 6, and 8) bearing long p-alkyl groups (R=hexyl or dodecyl) have been synthesized by "direct" acylation of the p-position followed by silane reduction.The method is convenient and the yields are higher than those reported so far.Among them, p-hexanoylcalix<4>arene showed a curious phase transition behavior; with raising the temperature it changed as crystal A -> liquid -> crystal B -> liquid.It was found on the basis of the solid 13C NMR spectra that this behavior is ascribed to a conformational change from "cone" (crystal A) to "partial cone" (crystal B).