posted on 2021-07-01, 15:39authored byAlisson Ceccatto
dos Santos, Nataly Herrera-Reinoza, Alejandro Pérez Paz, Duncan John Mowbray, Abner de Siervo
On-surface
coupling reactions and molecular conformation are essential
processes for building tailored functional molecular nanostructures.
Here, we study the thermal debromination and reactivity of free-base
tetra(4-bromophenyl)porphyrin (H2TBrPP) on Cu(111) as a
function of the substrate temperature. It has been previously reported
in the literature that C–Br bonds remain intact at room temperature
(RT) and that the Br···Cu(111) interaction induces
a drastic surface reconstruction around the molecule periphery and
a distortion in the adsorbate itself. However, based on a combination
of STM and XPS experiments, supported by density functional theory
(DFT) calculations, we instead demonstrate that debromination readily
occurs at RT, leading to a new interpretation of both the adsorption
behavior and the molecular coupling of H2TBrPP on Cu(111).
For the molecules deposited on the metallic substrate held above RT,
our STM measurements show the growth of ordered 2D metal–organic
frameworks (MOFs).