Helical Transfer through Nonlocal Interactions

A pair of chiral bola-type enantiomers, ll-12PyBr and dd-12PyBr, was synthesized. They can cause physical gels in pure water. Sol-gel transcriptions were carried out to control mesoporous 1,4-phenylene-silica nanostructures and helicity using the organic self-assemblies of these amphiphiles as templates. Under acidic conditions, left-handed helical 1,4-phenylene-silica bundles were prepared using the self-assemblies of ll-12PyBr as templates. Additionally, right-handed helical silica and 1,4-phenylene-silica bundles were prepared using the self-assemblies of dd-12PyBr as templates. Under basic conditions, 1,4-phenylene-silica bundles were also obtained. However, it is hard to determine the handedness. For all of the 1,4-phenylene-silica bundles, it is interesting to find that the aromatic rings are packing in helix within the wall of the pore channels. Powder X-ray diffraction patterns indicated that the aromatic rings of 1,4-phenylene-silica bundles prepared under basic conditions showed a greater degree of order than those of 1,4-phenylene-silica bundles prepared under acidic conditions. Moreover, helical silica, 1,3-phenylene-silica, ethene-silica, and ethane-silica bundles were also prepared using the self-assemblies ll-12PyBr and dd-12PyBr as templates.