Elettra-Sincrotrone Trieste S.C.p.A. website uses session cookies which are required for users to navigate appropriately and safely. Session cookies created by the Elettra-Sincrotrone Trieste S.C.p.A. website navigation do not affect users' privacy during their browsing experience on our website, as they do not entail processing their personal identification data. Session cookies are not permanently stored and indeed are cancelled when the connection to the Elettra-Sincrotrone Trieste S.C.p.A. website is terminated.
More info

MNCL Highlights

2H-TPP on Ag: carbon de-hydrogenation and geometrical adaptation

We observe a selective carbon de-hydrogenation, the formation of new aryl-aryl bonds between phenyl groups and the macrocycle, as well as the rotation of the phenyl rings in a flat conformation. Experiments and theoretical calculations prove this chemical reaction.

In our recent investigations we have demonstrated that one monolayer of 2H-TPP, prepared by thermal desorption of the corresponding multilayer at 550 K on Ag(111), adsorbs with the macrocycle and the phenyl flat. This information has been directly addressed by means of X-ray absorption and photoemission experiments.
 Theoretical calculations suggest a possible molecular reaction and modification of porphyrins, in order to explain this adsorption conformation: the de-hydrogenation of eight carbon atoms in the remaining monolayer after the multilayer desorption, with the formation of four new aryl-aryl carbon bonds.
While the reaction takes place also in the deposited monolayer annealed at 550 K, the initial presence of the multilayer favors a decrease of the aryl-aryl coupling barrier and the selection of a spiral conformation in the de-hydrogenated molecule. The chemical reaction produces a stable molecule that forms a patterned square lattice on Ag(111) and that can be further modified by the introduction of central metal atoms.


Retrieve article

Supramolecular Engineering through Temperature-Induced Chemical Modification of 2H-Tetraphenylporphyrin on Ag(111): Flat Phenyl Conformation and Possible Dehydrogenation Reactions

Giovanni Di Santo1, Stephan Blankenburg2, Carla Castellarin-Cudia1, Mattia Fanetti1, Patrizia Borghetti3, Luigi Sangaletti3, Luca Floreano4, Alberto Verdini4, Elena Magnano4, Federica Bondino4, Carlo A. Pignedoli2, Manh-Thuong Nguyen2, Roberto Gaspari2, Daniele Passerone2, Andrea Goldoni1,*

1INSTM—Micro & Nano-Carbon Laboratory, Sincrotrone Trieste S.C.p.A. s.s.14 km. 163.5, 34149 Trieste (Italy), Fax: +(39) 040-3758565Empa, Swiss Federal Laboratiories for 2Materials Science and Technology nanotech@surfaces Laboratory, Ueberlandstrasse 129, 8600 Dübendorf (Switzerland)
3Dipartimento di Matematica e Fisica and Interdisciplinary Laboratories for Advanced Materials Physics, Università Cattolica del Sacro Cuore, Brescia (Italy)
4Istituto Officina dei Materiali-CNR, Lab. TASC, s.s. 14 km 163.5, 34149 Trieste (Italy)


Chemistry - A European Journal vol 17, Issue 51, 14354, December 16, 2011
DOI: 10.1002/chem.201102268
Publication Date (Web): November 23, 2011
Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


Last Updated on Monday, 29 September 2014 18:21