Articolo in rivista, 2023, ENG, 10.1016/j.apsusc.2022.155307

Formation of diphenyl-bipyridine units by surface assisted cross coupling in Pd-cyclometalled complexes

Barcelon J.E.; Stojkovska M.; Perilli D.; Carraro G.; Smerieri M.; Vattuone L.; Rocca M.; Bracco G.;Dell'Angela M.; Costantini R.; Cossaro A.; Vaghi L.; Papagni A.; Di Valentin C.; Savio L.

IMEM-CNR, UOS Genova, Via Dodecaneso 33, 16146 Genova, Italy; Dipartimento di Scienze Chimiche, della Vita e della Sostenibilit`a Ambientale, Universit`a di Parma, Parco Area delle Scienze, 17/A, 43124 Parma, Italy; Dipartimento di Chimica, Universit`a degli Studi di Genova, Via Dodecaneso 31, 16146 Genova, Italy; Dipartimento di Scienza dei Materiali, Universit`a di Milano-Bicocca, Via R. Cozzi 55, 20125 Milano, Italy; Dipartimento di Fisica, Universit`a degli Studi di Genova, Via Dodecaneso 33, 16146 Genova, Italy; CNR-IOM, Strada Statale 14 - km 163.5, 34149 Trieste, Italy; Dipartimento di Scienze Chimiche e Farmaceutiche, Universit`a degli Studi di Trieste, via L. Giorgieri 1, 34127 Trieste, Italy

The Pd cyclometallated complex [(5-bromo-2-phenylpyridine)Pd(?-Cl)]2 is deposited on Ag(110) at room temperature by sublimation in ultra-high vacuum. The thermal evolution of the system is followed by scanning tunnelling microscopy and X-ray photoemission spectroscopy, while the initial and final configurations are validated by ab-initio calculations. We observe the surface induced dissociation of the molecule and the occurrence of a cross coupling reaction between the two organic fragments, leading to the surface assisted synthesis of diphenyl-bipyridine molecules. Such a process, occurring with low probability at RT, is thermally activated and competes with desorption. At variance with most cross-coupling reactions at surfaces reported in literature, in this case the reactants come from the dissociation of the same compound so that only one precursor is employed, leading to a simplified preparation protocol. The Br and Cl atoms dissociated from the molecule bind to the surface and promote an extended surface reconstruction upon annealing, which was not observed previously upon deposition of halogenated aromatic compounds.

Applied surface science 609 , pp. 155307-1–155307-10

Keywords

Cross coupling reactions, Pd cyclometallated compounds, STM, DFT

CNR authors

Rocca Mario Agostino, Vattuone Luca, Bracco Gianangelo, Costantini Roberto, Barcelon Jose Eduardo, Stojkovska Marija, Savio Letizia, Smerieri Marco, Dell Angela Martina, Carraro Giovanni, Cossaro Albano

CNR institutes

IMEM – Istituto dei materiali per l'elettronica ed il magnetismo, IOM – Istituto officina dei materiali