MORPHOLOGICAL-STUDIES OF CU(I)-COMPLEXED BIPYRIDINE-CONTAINING BLOCK-COPOLYMERS BY COMBINED TRANSMISSION ELECTRON-MICROSCOPY TECHNIQUES

The design of molecular species which can form well-defined macromolec ular architectures by spontaneous, recognition-directed self-assembly of their components is a major goal in supramolecular chemistry. We sy nthesized block copolymers with polyether and bipyridine or oligo(bipy ridine) containing segments where the latter could form double-helical structures by metal complexation. Upon complexation with Cu(I) these systems showed a dramatic change in the thermal and mechanical propert ies from a waxy system to a thermoplastic elastomeric behaviour. This effect could be explained by the formation of a multiphase polymer sys tem consisting of domains of bipyridine or oligo(bipyridine) Cu(I) com plexes in a matrix of amorphous soft segments. In the solution-east fi lms both nitrogen and copper could be detected with electron energy-lo ss spectroscopy. Element spectroscopic imaging pictures of the net nit rogen and copper element distribution were identical and revealed a mi crophase-separated system with identical morphological structures. Hig h-resolution bright-field images revealed fine structures (interferenc e lines) which were in accordance with stacks of [Cu(I)(bpy)(2)] compl exes. Electron diffraction patterns showed that the supramolecular ord er could be perfected through annealing.