Dynamics of Spatially Confined Bisphenol A Trimers in a Unimolecular Network on Ag(111)
Julian A. Lloyd, Anthoula C. Papageorgiou, Sybille Fischer, Seung Cheol Oh, Özge Saglam, Katharina Diller, David A. Duncan, Francesco Allegretti, Florian Klappenberger, Martin Stöhr, Reinhard J. Maurer, Karsten Reuter, Joachim Reichert, Johannes V. Barth, Nano Lett., 16, 1884-1889 (2016)
A combination of STM, XPS, NEXAFS experiments, Density Functional Theory and Density Functional Tight-Binding simulations reveals interesting thermally-induced confined dynamics of adsorbates.
Bisphenol A (BPA) aggregates on Ag(111) shows a polymorphism between two supramolecular motifs leading to distinct network formations depending on thermal energy. With rising temperature a dimeric pairing scheme reversibly converts into a trimeric motif, which forms a hexagonal superstructure with complex dynamic characteristics. The trimeric arrangements notably organize spontaneously into a selfassembled onecomponent array with supramolecular BPA rotors embedded in a twodimensional stator sublattice. By varying the temperature, the speed of the rotors can be controlled as monitored by direct visualization. A combination of scanning tunneling microscopy and dispersion-corrected Density-Functional Tight-Binding (DFTB-vdWsurf) based molecular modeling reveals the exact atomistic position of each molecule within the assembly as well as the driving force for the formation of the supramolecular rotors.