The macrocyclic biquinazoline ligand, H-Mabiq, presents a central and a peripheral site for the coordination of metal ions, making the adsorption on solid surfaces promising for the creation of self-assembled bimetallic two-dimensional platforms. Here, we apply an on-surface metalation strategy under ultra-high vacuum conditions to guide the synthesis of metalated species and study sequential metalation patterns. We find that cobalt (as well as iron) metalation on the Ag(111) surface preferentially occurs at the macrocyclic centre without further metal coordination to the peripheral site. Nevertheless, starting from a densely packed, self-assembled H-Mabiq monolayer, the modification of the central cavity by Co is accompanied by an unusual, metalation-induced phase transformation which gives evidence of modified lateral / interfacial interactions. The selective metalation of one molecular site opens up an on-surface route to create bimetallic networks incorporating select metal ions at different locations.

Metalloporphyrins on interfaces offer a rich playground for functional materials and hence have been subjected to intense scrutiny over the past decades. As the same porphyrin macrocycle on the same surface may exhibit vastly different physicochemical properties depending on the metal center and its substituents, it is vital to have a thorough structural and chemical characterization of such systems. Here, we explore the distinctions arising from coverage and macrocycle substituents on the closely related ruthenium octaethyl porphyrin and ruthenium tetrabenzo porphyrin on Ag(111). Our investigation employs a multitechnique approach in ultrahigh vacuum, combining scanning tunneling microscopy, low-energy electron diffraction, photoelectron spectroscopy, normal incidence X-ray standing wave, and near-edge X-ray absorption fine structure, supported by density functional theory. This methodology allows for a thorough examination of the nuanced differences in the self-assembly, substrate modification, molecular conformation and adsorption height.Metalloporphyrins on interfaces offer a rich playground for functional materials and hence have been subjected to intense scrutiny over the past decades. As the same porphyrin macrocycle on the same surface may exhibit vastly different physicochemical properties depending on the metal center and its substituents, it is vital to have a thorough structural and chemical characterization of such systems. Here, we explore the distinctions arising from coverage and macrocycle substituents on the closely related ruthenium octaethyl porphyrin and ruthenium tetrabenzo porphyrin on Ag(111). Our investigation employs a multitechnique approach in ultrahigh vacuum, combining scanning tunneling microscopy, low-energy electron diffraction, photoelectron spectroscopy, normal incidence X-ray standing wave, and near-edge X-ray absorption fine structure, supported by density functional theory. This methodology allows for a thorough examination of the nuanced differences in the self-assembly, substrate modification, molecular conformation and adsorption height.