Thin Solid Films, Vol.406, No.1-2, 228-232, 2002
Spreading monolayers and Langmuir-Blodgett films of a novel type of optically active macrocyclic poly(ether sulfone)s containing 1,1'-bi-2-naphthol moiety
Aimed at investigating the monolayers and Langmuir-Blodgett (LB) films of compounds without any substituted alkyl chains and constructing chiral ultrathin films, a new group of optically active macrocyclic poly(ether sulfone)s containing a binaphthyl group, which have no substituted alkyl chains, were synthesized. The spreading behavior and the ultrathin film fabrication of these compounds was studied. Stable monolayers with collapse surface pressures up to 40 mN m(-1) were formed at the air/water interface and uniform LB films were fabricated by using the horizontal lifting method, The optical activities of the compounds were maintained in the LB films. Transferred LB films were characterized by UV-vis, fluorescence and circular dichroism spectroscopy. It was found that the (1)Bb, L-1(a) and L-1(b) bands of the compounds showed a red shift compared with the corresponding solutions. While no split of the Cotton effect was observed for the dimeric compound, strong exciton couplings that could be ascribed to the interactions between the naphthyl groups were observed for the trimeric macrocyclic compounds.
Keywords:monolayers;Langmuir-Blodgett films;chiral compounds;macrocyclic poly(ether sulfone)s;1,1 '-bi-2-naphthol