Surface-confined 2D polymerization of a brominated copper-tetraphenylporphyrin on Au(111).

A coupling-limited approach for the Ullmann reaction-like on-surface synthesis of a two-dimensional covalent organic network starting from a halogenated metallo-porphyrin is demonstrated. Copper-octabromo-tetraphenylporphyrin molecules can diffuse and self-assemble when adsorbed on the inert Au(111) surface. Splitting-off of bromine atoms bonded at the macrocyclic core of the porphyrin starts at room temperature after the deposition and is monitored by X-ray photoelectron spectroscopy for different annealing steps.

Site-dependent donation/backdonation charge transfer at the CoPc/Ag(111) interface.

The organic/metal interface formed upon adsorption of cobalt(II) phthalocyanine (CoPc) molecules on a flat Ag(111) single crystal was investigated using a combination of scanning tunneling microscopy (STM) and photoemission spectroscopy (PES). A flat-lying molecular adsorption with the π conjugated phthalocyanine ligand parallel to the substrate was found to lead to an effective molecule-substrate coupling which governs a template-guided molecular growth. A voltage polarity dependence at the cobalt ion site was emphasized and correlated with the Co 2p core level spectra evolution which sustains an interface-confined reduction effect of the cobalt oxidation state.