Layer-by-Layer Epitaxy of Porphyrin−Ligand Fe(II)-Fe(III) Nanoarchitectures for Advanced Metal–Organic Framework Growth

Abstract

Precisely layered molecular heterostructures are promising but still largely unexplored materials, with the potential to complement and enhance the scope of two-dimensional heterostructures. The controlled epitaxial growth of vertically stacked molecular layers connected through tailored linkers, can lead to significant development in the field. Here, we demonstrate that sequential assembly of prototypical iron porphyrins and axial ligands can be steered via temperature-programmed desorption, and monitored by mass spectrometry and by high-resolution atomic force microscopy under ultrahigh vacuum conditions. Complementary photoelectron spectroscopy analysis delivers chemical insight into the formation of layer-by-layer nanoarchitectures. Our temperature-directed methodology outlines a promising strategy for the in vacuo fabrication of precisely stacked, multicomponent (metal−organic) molecular heterostructures.

Assembly and Manipulation of a Prototypical N-Heterocyclic Carbene with a Metalloporphyrin Pedestal on a Solid Surface

“…However, hitherto, the functionalization of such metalloporphyrin pedestals with commonly employed ligands of supramolecular chemistry on metal surfaces has proven challenging. For example, binding would occur only at low temperatures (below room temperature), , limiting its applicability, whereas another ligand was found to intercalate between the metal porphyrin and the surface …”

“…However, hitherto, the functionalization of such metalloporphyrin pedestals with commonly employed ligands of supramolecular chemistry on metal surfaces has proven challenging. For example, binding would occur only at low temperatures (below room temperature), 19,20 limiting its applicability, whereas another ligand was found to intercalate between the metal porphyrin and the surface. 21 To assess whether metalloporphyrins can provide a suitable pedestal for the atomically precise positioning and arrangement of NHCs, we investigate the NHC interaction with a single layer of metalloporphyrins on a metal surface.…”

Synthesis, characterization, and spectroscopic properties of 2‐(3,5,6‐trichloro‐1,4‐benzoquinon‐2‐yl)‐neo‐fused hexaphyrin

“…In past decades, porphyrins have attracted considerable interest because of their interesting coordination, photophysical, and optoelectronic properties applicable in various areas like coordination chemistry, catalysis, chemosensors, and solar cells 1 . In recent years, porphyrinoids such as expanded porphyrins 2 and N‐confused porphyrins 3 have been developed by changing the macrocyclic frameworks of porphyrins.…”

Out‐Of‐Plane Metal Coordination for a True Solvent‐Free Building with Molecular Bricks: Dodging the Surface Ligand Effect for On‐Surface Vacuum Self‐Assembly

“…[ 12 ] Conversely, solvent‐less SA is practically unexplored. In fact, a recent study just appeared in literature, [ 13 ] while the present work was in the submission stage. Nonetheless, the low temperature construction therein reported still requires the use of a molecular precursor in order to join the building blocks, whereas we succeed in obtaining a molecule‐molecule bonding, at room temperature, via a direct lego building process.…”