Calixarene-modified chitosans (CTS-CA-I and CTS-CA-II) were first synthesized by the reaction of chitosan (CTS-NH 2 ) with 1,3-bis-chloroethoxyethoxy-2,4-dihydroxy-p-tert-butylcalix[4]arene (CA-I) or its benzoyl derivative (CA-II). Their structures were characterized by infrared and X-ray diffraction spectroscopy and scanning electron microscopy (SEM).

The synthesis and conformation of di-O-bridged homooxacalix[3]arenes were reported. Their recognition ability towards alkylammonium ions was studied with the aid of NMR. Two of them show selective binding ability towards relatively longer linear alkylammonium ions (CH 3 (CH 2 ) n NH 3 , ＋ n＝3-5).