title: Temperature-induced structural phase transitions in a two-dimensional self-assembled network.
abstract: Two-dimensional (2D) supramolecular self-assembly at liquid-solid interfaces is a thermodynamically complex process producing a variety of structures. The formation of multiple network morphologies from the same molecular building blocks is a common occurrence. We use scanning tunnelling microscopy (STM) to investigate a structural phase transition between a densely packed and a porous phase of an alkylated dehydrobenzo[12]annulene (DBA) derivative physisorbed at a solvent-graphite interface. The influence of temperature and concentration are studied and the results combined using a thermodynamic model to measure enthalpy and entropy changes associated with the transition. These experimental results are compared to corresponding values obtained from simulations and theoretical calculations. This comparison highlights the importance of considering the solvent when modeling porous self-assembled networks. The results also demonstrate the power of using structural phase transitions to study the thermodynamics of these systems and will have implications for the development of predictive models for 2D self-assembly.
authors.affiliation: Department of Chemistry, Division of Molecular Imaging and Photonics, Laboratory of Photochemistry and Spectroscopy, KU Leuven - University of Leuven, Celestijnenlaan 200 F B2404, B-3001 Leuven, Belgium. m.blunt@ucl.ac.uk
authors.forename: Matthew O
authors.initials: MO
authors.lastname: Blunt
authors.forename: Jinne
authors.initials: J
authors.lastname: Adisoejoso
authors.forename: Kazukuni
authors.initials: K
authors.lastname: Tahara
authors.forename: Keisuke
authors.initials: K
authors.lastname: Katayama
authors.forename: Mark
authors.initials: M
authors.lastname: Van der Auweraer
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Tobe
authors.forename: Steven
authors.initials: S
authors.lastname: De Feyter