Steinrück HP, Stark MW, Ditze S, Thomann M, Lungerich D, Jux N, Marbach H (2016)
Publication Status: Published
Publication Type: Journal article, Original article
Publication year: 2016
Publisher: Elsevier
Book Volume: 650
Pages Range: 255-262
DOI: 10.1016/j.susc.2015.11.024
We investigated the adsorption behavior of Co(II)-5,10,15,20-tetrakis-(3,5-di-tert-butylphenyl)-porphyrin (CoTTBPP) on Cu(111) by scanning tunneling microscopy (STM). At room temperature (RT), the coverage dependent adsorption behavior follows an expected scheme: at low coverage step decoration is found, which evolves into supramolecular domains with a hexagonal order at higher coverage. Interestingly, upon cooling the sample to 180 K the occurrence of a clearly distinguishable coexisting herringbone phase is observed. Upon heating to RT again, the herringbone phase vanishes. Thus a temperature dependent, fully reversible phase transition was observed. High resolution STM micrographs allow for the determination of the intramolecular conformations which are different for the two supramolecular arrangements. In addition, we studied the bias voltage dependent appearance of the molecule in STM and assigned a dominant contribution of the central Co at negative bias voltages close to the Fermi edge to the occupied d orbital. Interestingly, the herringbone phase, which dominates at 180 K, exhibits a significantly higher molecular density than the monomodal hexagonal arrangement at RT, which is in line with the "normal" behavior of freezing substances.
APA:
Steinrück, H.-P., Stark, M.W., Ditze, S., Thomann, M., Lungerich, D., Jux, N., & Marbach, H. (2016). Reversible thermally induced phase transition in ordered domains of Co(II)-5,10,15,20-tetrakis-(3,5-di-tert-butylphenyl)-porphyrin on Cu(111). Surface Science, 650, 255-262. https://doi.org/10.1016/j.susc.2015.11.024
MLA:
Steinrück, Hans-Peter, et al. "Reversible thermally induced phase transition in ordered domains of Co(II)-5,10,15,20-tetrakis-(3,5-di-tert-butylphenyl)-porphyrin on Cu(111)." Surface Science 650 (2016): 255-262.
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