Molecules on 2D Templates: Quantitative Interface Structure Determination and OnSurface Reactions

Two-dimensional (2D) epitaxial materials including hexagonal boron nitride (hBN) are frequently employed as templates for self-assembled molecular films and nanostructures [1]. A quantitative structural characterization of the respective interfaces and adsorbate geometries however is largely missing. After reviewing some examples of molecular self-assembly on hBN, I will report on the geometric and electronic structure of a prototypical organic/insulator/metal interface, namely metalloporphines (Co-P, Zn-P) on hBN/Cu(111), investigated by combining X-ray photoelectron spectroscopy, X-ray standing waves, and scanning tunneling microscopy [2]. In a second part of my presentation, I plan to address onsurface reactions that are operational on hBN/Cu(111), covering the formation of polyaromatic azaullazine chains via intermolecular cyclization and preliminary results on the synthesis of Thporphyrin complexes. These actinide-based double-decker structures complement related lanthanide-based systems [3].

[1] W. Auwärter, Surf. Sci. Rep., doi:10.1016/j.surfrep.2018.10.001

[2] M. Schwarz et al., Nanoscale 10, 21971 (2018)

[3] D. Ecija et al., Acc. Chem. Res. 51, 365 (2018)