Regensburg 2019 – scientific program
O 83.6: Talk
Thursday, April 4, 2019, 16:30–16:45, H9
Large thermal expansion of a self-assembling monolayer in UHV — •Sebastian Scherb1, Antoine Hinaut1, Guilherme Vilhena1, Rémy Pawlak1, Akimitsu Narita2, Thilo Glatzel1, and Ernst Meyer1 — 1Department of Physics, University of Basel, Basel, Switzerland — 2Max Planck Institute for Polymer Research, Mainz, Germany
Self-assemblies of structurally complex molecules in UHV provide interesting prospects for applications in optoelectronics, nanomechanical devices and molecular electronics. To investigate their viability for specific applications, high-resolution studies of their behavior under a variety of conditions are required.
In this study we report the experimental and theoretical study of the adsorption behavior of a molecular assembly on Au(111) under different thermal conditions. A shape persistent polyphenylene Spoked Wheel molecule  was deposited onto Au(111) surfaces in UHV by electrospray deposition . The assembly formation studied at room temperature by ncAFM and at low temperature by STM/AFM shows a large positive thermal expansion coefficient from LT to RT. Comparing with molecular dynamics simulations we propose an explanation of the mechanism of expansion due to alkyl chain mobility in combination with increased molecular diffusion.
 Liu, Y. et al., J. Am. Chem. Soc., 138, 15539-15542 (2016).  Hinaut et al., Nanoscale, 10, 1337-1344 (2018).