Self‐Metalation of Porphyrins at the Solid–Gas Interface

Abstract

Self-metalation is ap romising route to include as ingle metal atom in at etrapyrrolic macrocycle in organic frameworks supported by metal surfaces.T he molecule-surface interaction may providet he charge transfer and the geometric distortion of the molecular plane necessary for metal inclusion. However,a tametal surface the presence of an activation barrier can represent an obstacle that cannot be compensated by ah igher substrate temperature without affecting the layer integrity.The formation of the intermediate state can be facilitated in some cases by oxygen pre-adsorption at the supporting metal surface,l ike in the case of 2H-TPP/ Pd(100). In such cases,the activation barrier can be overcome by mild annealing,y ielding the formation of desorbing products and of the metalated tetrapyrrole.W eshow here that the self-metalation of 2H-TPP at the Pd(100) surface can be promoted already at room temperature by the presence of an oxygen gas phase at close-to-ambient conditions via an Eley-Rideal mechanism.

Stabilization and activation of molecular oxygen at biomimetic tetrapyrroles on surfaces: from UHV to near-ambient pressure

“…However, it has been recently proven that by exposing the 2H-TPP/Pd(100) monolayer to 1 mbar O 2 the self-metalation reaction to PdTPP can be induced already at room temperature. 49 Evidence has been obtained by means of in situ IR-Vis SFG measurements ( Fig. 7a ).…”

“…oxygen binding, stabilization, and activation at Co tetrapyrroles on Au(111), 16 and the oxygen-induced self-metalation of 2H-TPP on Pd(100). 49 …”