Role of the Anchored Groups in the Bonding and Self-Organization of Macrocycles: Carboxylic versus Pyrrole Groups

• Published in: Journal of physical chemistry. C 2013-04, Vol.117 (15), p.7661-7668
• Main Authors: González-Moreno, Rubén, Garcia-Lekue, Aran, Arnau, Andrés, Trelka, Marta, Gallego, José M, Otero, Roberto, Verdini, Alberto, Sánchez-Sánchez, Carlos, de Andrés, Pedro L, Martín-Gago, José Ángel, Rogero, Celia
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electron states; Exact sciences and technology; Materials science; Methods of electronic structure calculations; Methods of nanofabrication; Organic compounds; Physics; Self-assembly; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp4005949

A combination of variable temperature scanning tunneling microscopy, near edge X-ray adsorption fine structure and density functional theory has been used to investigate the chemisorption and self-assembly of metal-free protoporphyrin IX molecules on Cu(110) surface. The molecules in contact with the substrate suffer irreversible molecular transformations, mainly deprotonation of the carboxylic groups and metalation of the pyrroline subunits. The carboxylate group has been revealed as the anchored group versus the tetrapyrrole ring. We study the role played by the carboxylic acid groups in the surface-molecular bonding and how its presence affects the supramolecular structure.