Fiche publication


Date publication

août 2017

Journal

Small (Weinheim an der Bergstrasse, Germany)

Auteurs

Membres identifiés du Cancéropôle Est :
Dr BELLEMIN-LAPONNAZ Stéphane


Tous les auteurs :
Garah ME, Borré E, Ciesielski A, Dianat A, Gutierrez R, Cuniberti G, Bellemin-Laponnaz S, Mauro M, Samorì P

Résumé

The use of a bottom-up approach to the fabrication of nanopatterned functional surfaces, which are capable to respond to external stimuli, is of great current interest. Herein, the preparation of light-responsive, linear supramolecular metallopolymers constituted by the ideally infinite repetition of a ditopic ligand bearing an azoaryl moiety and Co(II) coordination nodes is described. The supramolecular polymerization process is followed by optical spectroscopy in dimethylformamide solution. Noteworthy, a submolecularly resolved scanning tunneling microscopy (STM) study of the in situ reversible trans-to-cis photoisomerization of a photoswitchable metallopolymer that self-assembles into 2D crystalline patterns onto a highly oriented pyrolytic graphite surface is achieved for the first time. The STM analysis of the nanopatterned surfaces is corroborated by modeling the physisorbed species onto a graphene slab before and after irradiation by means of density functional theory calculation. Significantly, switching of the monolayers consisting of supramolecular Co(II) metallopolymer bearing trans-azoaryl units to a novel pattern based on cis isomers can be triggered by UV light and reversed back to the trans conformer by using visible light, thereby restoring the trans-based supramolecular 2D packing. These findings represent a step forward toward the design and preparation of photoresponsive "smart" surfaces organized with an atomic precision.

Mots clés

density functional theory (DFT), functional surfaces, metallopolymers, photoswitches, scanning tunneling microscopy (STM)

Référence

Small. 2017 Aug;: