Monolayer and LB films of amphiphilic 8-hydroxyquinoline derivatives

The surface pressure-area isotherms of the monolayers of three kinds of amp hiphilic derivatives of 8-hydroxyquinoline, N-hexadecyl-8-hydroxy-2-quinoli necarboxamide (I), 2-hexadecyloxycarbonyl-8-hydroxyquinoline (2) and 8-hexa decyloxy-2-quinaldinic acid (3) at an air-water interface on subphases with and without metal ion were investigated and compared with each other. Some information regarding the packing density and phase transition under diffe rent experimental conditions has been obtained. At the air-water interface 1, 2 and 3 can form metal complexes with Cu2+ ion present in the aqueous ph ase. The formation of complexes leads to changes in the area per molecule a nd the collapse pressure of thc monolayer. X-ray photoelectron spectroscopy analysis reveals Cu-ligand ratios in the LB films to he Lu. 1:1 for 1 and 2 and 1:2 for 3. Low-angle X-ray diffraction measurements showed the LB fil ms of 1, 2 and 3 deposited from CuCl2 subsolution had good homogeneity and were Y-type bilayer films.