Molecular anchoring stabilizes low valence Ni(i)TPP on copper against thermally induced chemical changes

Abstract

<p>The strong molecule-surface interaction, followed by charge transfer at the interface, plays a fundamental role in the thermal stability of the layer by rigidly anchoring the porphyrin molecules to the copper substrate.</p>

Conformational Control of Chemical Reactivity for Surface‐Confined Ru‐Porphyrins

“…This effect is associated with the different molecular shapes of other product species that do not fit into the expressed overlayer lattice (Figure S5). [25] The(stepwise) exposure of this layer to doses of CO at 150 Kresulted in saturating exclusively all Ru-TPP centres with CO (Figure 4H), whereas no changes were encountered for the Ru-TPP pl species.A ni ntermediate CO coverage acquired at negative bias (Figure 4G)highlights the difference in STM appearance between Ru-TPP,R u(CO)-TPP and Ru-TPP pl (see also Figure S5).…”

Reversible redox reactions in metal-supported porphyrin: the role of spin and oxidation state

“…These molecular levels, delocalized over the entire molecular macrocycle of CoTPP, are filled due to the charge transfer occurring at the organic/metal interface, as a result of the strong anchoring of the Co ion to the copper substrate. 43,44 As discussed above, in the Cu-CoTPP-NO 2 complex the Co-Cu interaction is weakened by the surface trans-effect, as evident from the quenching of the LUMOs features (see Fig. 4).…”

Insight into intramolecular chemical structure modifications by on-surface reaction using photoemission tomography

“…Indeed, it has been shown for various organic/metal interfaces that there exists a one-to-one correspondence between the momentum distribution of the photocurrent and the molecular orbitals in the reciprocal space. [12][13][14][15]20 In that way, the features observed for the CoOEP/ Ag(100) system can be unequivocally assigned to the molecular states simulated for the gas-phase CoOEP, where the states centered at BE 2.15 eV, 1.75 eV and 0.65 eV are due to the HOMOÀ1, HOMO and degenerate LUMO/LUMO+1, respectively. No match for the annealed interface can be found between the measured maps and the CoOEP calculated maps, while the momentum maps simulated for CoTBP match very well the three measured patterns at 2.15 eV, 1.60 eV and 0.70 eV for the annealed interface, which according to the present calculation can be assigned to the HOMOÀ1, HOMO and LUMO/LUMO+1 molecular states of CoTBP, respectively.…”

“…Only indirect conclusions can be made from, e.g., the presence or absence of specific vibrational modes in infrared spectroscopy or chemical shifts in core-level spectroscopy. Moreover, although providing an excellent insight into the molecular backbone structure, STM is less conclusive about the molecular periphery, where adsorbates tend to react with the substrate, and the geometrical and chemical changes observed are convoluted with the substrate electron density changes, 15 leaving room for alternative interpretations. The kinetics of the ring-closure reaction depends on a fine interplay between steric hindrance among adjacent molecules and substrate reactivity.…”

“…In the past, the photoemission tomography (PT) approach 12 has been employed to study the geometry and the electronic structure of the macrocycle in self-assembled porphyrin and its derivatives. [13][14][15] Additionally, it has been applied to study the pathway of thermally-activated on-surface intermolecular reactions. 16 In the present work, we will show that the PT approach can also be extended to the study of surfaceinduced intramolecular modifications, i.e., ring-closure reaction, in single molecules self-assembled in molecular arrays.…”