Noncovalent Synthesis and Structural Properties of Supramolecular Polymer Architectures from Bola-Form Amphiphiles

Construction of fibrous polymer architectures by the self-assembling of 1-glucosamide, 1-galactosamide, oligoglycine, and oligopeptide bola-form amphiphiles (bolaamphiphiles) has been described. Self-assembled polymer architectures of the 1-glucosamide bolaamphiphiles in water strongly depend on whether the carbon number of the oligomethylene spacer is even or odd. They respectively give rise to fibrous assemblies or planar platelets as well as amorphous solids. This finding provides the first example of a stereochemical effect due to even-odd connecting links on the assemblies. Molecular arrangements and hydrogen-bond networks of the 1-glucosamide and 1-galactosamide assemblies were investigated using FT-IR spectroscopy, X-ray diffraction, and crystal analyses. Sodium salts of the oligoglycine-based bolaamphiphiles also formed fibrous assemblies in water. Light microscopy for the assemblies clearly showed that tubular structures encapsulated a large number of vesicular assemblies inside them. This is the first example of vesicle~encapsulated microtubes with closed ends. We also investigated the molecular arrangement and hydrogen-bond networks within the tubes by using AFM, FT-IR and X-ray crystal analyses. A possible mechanism of the tube formation has been discussed.