Abstract
Calixarenes having long chain alkyl groups such as n-octyl, nonyl or n-dodecyl have been synthesized by heating the corresponding alkylphenol with HCHO in xylene in the presence of NaOH. These products are the mixture of octamer, heptamer and hexamer, and the calixarene homologs are isolated and characterized. The spectroscopic characteristics of calixarenes depend on the number of phenolic nuclei, that is, cavity size and not on the substituted alkyl groups. The long chain alkylcalixarenes show a strong intramolecular hydrogen bonding between phenolic OH. The lower melting point and the higher solubility in CHCl3 and C6H6 are observed compared with t-butylcalixarene. The reaction conditions for calixarene synthesis have been studied more detail. NaOH or KOH is the most active catalyst and the molar ratio (MOH/phenol) of 0.5 is the optimun condition. Thus, the yields of octyl-, nonyl- and dodecylcalixarne are 90%. 60% and 55%, respectively.
