Complex formation of water-soluble polyparacyclophanes bearing two diphenylmethane or two diphenyl ether skeletons with l-anilinonaphthalene-8-sulfonate (ANS) and 2-p-toluidinylnaphthalene-6-sulfonate (TNS) was investigated quantitatively to develop useful host compounds comparing with

})
in aqueous solution. Benesi-Hildebrand type analysis of the fluorescent intensity showed that the dissociation constants (Kd) of paracyclophane-ANS complexes were

for 1,6,20,25-tetraaza[6.1.6.1]paracyclophane(CPM 44) and

for 1,7,21,27-tetraaza[7.1.7.1]paracyclophane (CPM 55), and those of paracyclophane-TNS complexes were

for CPM 44 and

for CPM 55, in 1:1 molar ratio. On the other hand, the Kd values of 1,7,21,27-tetraaza-14,34-dioxa[7.1.7.1]paracyclophane (CPE 55)-ANS, 1,8,22,29-tetraaza-15,36-dioxa[8.1.8.1]paracyclophane (CPE 66)-ANS, CPE 55-TNS, CPE 66-TNS complexes were

,

,

and

, respectively. On the contrary, the Kd values of

,

,

and

complexes were found to be

,

,

and

, respectively. These results mean that the complexation of CPMs with ANS or TNS is by 5.6-1,975 fold stronger than that for

, and the complex formation of CPEs with ANS or TNS is nearly same as or somewhat stronger than that for

. From the Kd values determined at different temperatures, thermodynamic parameters were calculated and the complexation was found to be a spontaneous exothermic reaction. The effects of pH on Kd values of CPM 44-ANS, and CPM 55-ANS complexes were negligible in the range of pH 1.2-1.8. However, the Kd values of these complexes increased significantly with increasing ionic strength.