Langmuir, Vol.17, No.4, 1143-1149, 2001
Monolayers of novel calix[4]arene derivative and its palladium(II) complexes formed at the air-water interface
5,11,17,23-Tetra-tert-butyl-25,27-di{[(2'-amino-4'-methylthio)butyryl]aminoethoxy}-26,28-dihydroxycalix[4]- arene (L) and its mono- and binuclear palladium(II) complexes (PdLCl2 and Pd2LCl4) were synthesized. Their monolayers at the air-water interface were investigated by film balance measurements (compression/expansion experiments, area relaxation experiments, viscosity measurements) and Brewster angle microscopy. The monolayer oft is inclined to form domains and multilayers, while the monolayer of PdLCl2 demonstrates good reversibility and high collapse pressure. The monolayer formed by Pd2LCl4 exhibits extraordinary cohesiveness, stability, and robustness. Its extraordinary properties are likely due to the intermolecular cross-linkage of precursor complex of Pd2LCl4 via strong chloride bridges. This provides an example of improving mechanical, properties of film through intermolecular metal complexing.