New polymer architectures by surface-confined reactions
In collaboration with the group of Prof. Rosei (INRS), we explore the application of surfaces in Ultra-High Vacuum as templates for "epitaxial" growth of conjugated polymers. The catalytic properties of the surface are used to trigger the chemical reactivity of the corresponding monomers, while the directionality of crystalline surfaces acts allows to control the orientation and long-range order of the formed polymer. The great potential of such approach lies in possibility of creating integrated molecular electronics circuits (incorporating molecular wires, diodes, transistors, etc) in a "bottom-up" approach. Furthermore, completely new polymer architectures (such as two-dimensional polymer) could be prepared by surface-confined polymerization.
The image below shows highly ordered stacks of substituted thiophene oligomers prepared by dosing the monomer, dibromoEDOT on Cu(110) surface. Note, that the strong interaction of molecules with the surface not only controls the long-range order of the monolayer, but also leads to the previously unknown all-cis geometry of PEDOT (all sulfurs on the same side).
Figure below shows the STM studies of host-guest self-assembly of terthienobenzenetricarboxylic acid with C60 fullerene, as a model "bulk heterojunction" system for organic photovoltaics (solar cells).
Step-by-step growth of aligned polythiophene wires by surface-confined oligomerization,
J.A. Lipton-Duffin, J.A. Miwa, M. Kondratenko, F. Cicoira, B.G. Sumpter, V. Meunier*, D.F. Perepichka*, F. Rosei*, Proc. Nat. Acad. Sci. USA. 2010, 107, 11200-11204.
Extending Polymer Conjugation in the Second Dimension,
D. F. Perepichka, F. Rosei, Science 2009, 323, 216-217.
Synthesis of polyphenylene molecular wires by surface confined polymerization,
J. A. Lipton-Duffin, O. Ivasenko, D. F. Perepichka, F. Rosei, Small 2009, 5, 592-597.
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