Molecular Devices Based on New Monolayer-Forming Systems.

摘要

The formation of novel planar lattices formed by monolayers of new amphiphiles molecules is reported. The rigid amphiphiles have cross-sections designed to provide two-dimensional crystals of the hexagonal, rectangular and oblique crystal classes. The packings are studied by atomic force microscopy. One amphiphile of triangular cross-section forms a hexagonal lattice. Two other amphiphiles, a tetracyclic and binapthyl, are chiral and synthesized as racemates. The single binapthyl amphiphile forms two commensurate lattices, rectangular and oblique, in the same monolayer. The tetracyclic amphiphile shows three phases on water and upon transfer at their respective formation pressures onto mica, three phases are observed: glass-like, rectangular and oblique. The oblique phase results as a phase separation of the enantiomers as a result of spontaneous resolution in two dimensions. Atom-atom potential calculation are shown to be essential to the design and understanding of these planar lattices. The results have important implications beyond monolayer chemistry and physics for fields such as liquid crystals and biophysics. Monolayer films; Langmuir-Blodgett films, spontaneous optical resolution, commensurate lattices, phase transitions; packing.