Syntheses and Cation Extraction Properties of Polycalixarenes from p-Hydroxycalix[6]arene

A new polymer, polycalixarene, was prepared by the reaction of p- hydroxycalix[6]arene (HQ[6]) with paraformaldehyde under HCl acidic conditions. HQ[6] had two types of hydroxyl groups at the upper and lower rims and showed a conelike conformation. The conformation of the HQ[6] unit was maintained in the polymer chain. The extraction ability of poly( p- hydroxycalix[6]arene) (P - HQ[6]) for alkali metal cations was determined and compared with that of the monomeric HQ[6]. The extraction ability of P - HQ[6] was higher than that of HQ[6] due to new cation binding sites consisting of the aggregated HQ[6] units in the polymer. The affinity and selectivity of new binding sites depended on the aggregated state of HQ[6] units in the polymer chain. The aggregated state was controlled by the conformation of the polymer.