POLYION-COMPLEXED ASSEMBLIES OF DIACETYLENIC CARBOXYLIC-ACID WITH TRIBLOCK POLYAMINE CARRYING A BORONIC ACID-FUNCTIONALIZED SEGMENT

The polyion complex of 10,12-pentacosadiynoic acid 1 and a novel ABA-t ype triblock polyamine 2, containing phenylboronic acid groups as suga r-responsive sites, has been prepared. Monolayer properties of the com plex 2/1 are examined by measuring surface pressure (pi)-area (A) isot herms on water. The pi-A curves are found to vary drastically by chang ing pH in the subphase, suggesting the conformational change of the co polymer segment of 2 containing phenylboronic acid groups and/or defor mation of the polyion complex of 2/1. Polymerizations of the complex m onolayer of 2/1 are carried out upon UV irradiation, resulting in succ essful production of polydiacetylene with a blue form under optimum co nditions of pH, temperature, substrate, surface pressure and so on. Wh en the polymerized 2/1 LB film deposited on a quartz plate is immersed in aqueous solutions of various diol compounds such as sugars and nuc leosides, a remarkable spectral variation due to blue to red color pha se change of the polydiacetylene matrices is observed, implying bindin g of the diol compounds to the phenylboronic acid moieties located at the LB him surface. The extent of the spectral variation of the LB fil m seems to be proportional to the binding ability for the diol compoun ds.