Divergent Synthesis of Molecular Winch Prototypes

• Published in: Chemistry : a European journal Vol. 27; no. 65; pp. 16242 - 16249
• Main Authors: Gisbert, Yohan, Abid, Seifallah, Kammerer, Claire, Rapenne, Gwénaël
• Format: Journal Article
• Language: English
• Published: Wiley-VCH Verlag 22-11-2021
• Subjects: Chemical Sciences; Coordination chemistry; fullerene; molecular machine; molecular winch; porphyrin; triptycene; molecular machine; porphyrin; triptycene; fullerene; molecular winch
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202103126

We report the synthesis of conceptually new prototypes of molecular winches with the ultimate aim to investigate the work performed by a single ruthenium‐based molecular motor anchored on a surface by probing its ability to pull a load upon electrically‐driven directional rotation. According to a technomimetic design, the motor was embedded in a winch structure, with a long flexible polyethylene glycol chain terminated by an azide hook to connect a variety of molecular loads. The structure of the motor was first derivatized by means of two sequential cross‐coupling reactions involving a penta(4‐halogenophenyl)cyclopentadienyl hydrotris(indazolyl)borate ruthenium(II) precursor and the resulting benzylamine derivative was next exploited as key intermediate in the divergent synthesis of a family of nanowinch prototypes. A one‐pot method involving sequential peptide coupling and Cu‐catalyzed azide‐alkyne cycloaddition was developed to yield four loaded nanowinches, with load fragments encompassing triptycene, fullerene and porphyrin moieties.
Molecular machine: A family of loaded molecular winches were designed and synthesized as prototypes for mechanical studies at the single‐molecule scale. The molecular winch structure derives from a molecular motor based on a ruthenium complex and is covalently linked to a series of molecular loads such as triptycene, fullerene and porphyrin fragments.