Self-assembly and oligomerization of alkyne-terminated molecules on metal and oxide surfaces

We report the self-assembly and subsequent oligomerization of organic molecules based on terthiophenes bearing a terminal alkyne moiety. Molecules with thioacetate and phosphonic acid functional groups were synthesized, enabling molecular self-assembly on metal (Au and Pd) and metal oxide [Al(2)O(3), HfO(2), and indium tin oxide (ITO)] surfaces, respectively. The molecules were assembled from solution and then oligomerized using either 2,5-norbornadiene-rhodium(I) chloride dimer or UV light. UV-vis and infrared absorption spectroscopies and electrochemical techniques show that the molecules assemble to form dense monolayers on the substrate surfaces and oligomerize under the action of a catalyst or UV light.