Force Reveals Hidden Conformations and Dissociation Pathways in Individual π‐Interacting Dimers

[en] Harnessing mechanical force to control molecular structure is a central strategy in the design of mechano‐responsive materials. Noncovalent interactions are particularly attractive in this context because of their reversibility and tunable mechanical stability, yet the conformational energy landscapes of such motifs often remain inaccessible to conventional ensemble techniques. Here, we use atomic force microscopy‐based force spectroscopy to probe individual π‐interactions within a perylene diimide dimer. Single‐molecule pulling experiments combined with molecular dynamics simulations reveal two distinct long‐lived conformers with parallel and anti‐parallel perylene diimide orientations that are indistinguishable by ensemble techniques. The parallel conformer exhibits greater mechanical stability and ruptures through a sequential pathway in which the dimer converts to an anti‐parallel arrangement before π–π dissociation. Passive force spectroscopy resolves both conformers in real‐time, validates the force‐induced interconversion pathway predicted by steered molecular dynamics simulations, and quantifies their mechanical resistance and lifetime under constant load. Together, these results show that combining passive force spectroscopy with molecular simulations can reveal hidden conformational states in noncovalent assemblies and map their force‐dependent energy landscape. Our findings provide molecular‐level insight into the mechanics of π–π interactions and highlight single‐molecule force spectroscopy as a powerful approach to uncover hidden structural states in supramolecular systems.

Disciplines :

Chemistry

Author, co-author :

Franceschini, Célia ^✱; Université de Liège - ULiège > Molecular Systems (MolSys)

Brandt, Dorothée ^✱; Laboratory For Computational Modelling of Functional Materials Namur Institute of Structured Matter University of Namur Belgium

Ledent, Maxime ; Université de Liège - ULiège > Département de chimie (sciences) > Nanochimie et systèmes moléculaires

Carabin, Thomas ; Université de Liège - ULiège > Molecular Systems (MolSys)

Traeger, Hanna ; Adolphe Merkle Institute University of Fribourg Fribourg Switzerland ; NCCR Bio‐inspired Materials University of Fribourg Fribourg Switzerland

Clough, Jess M. ; Adolphe Merkle Institute University of Fribourg Fribourg Switzerland ; NCCR Bio‐inspired Materials University of Fribourg Fribourg Switzerland

Muccioli, Luca ; Department of Industrial Chemistry University of Bologna Bologna Italy

Duwez, Anne-Sophie ; Université de Liège - ULiège > Département de chimie (sciences) > Nanochimie et systèmes moléculaires

Weder, Christoph ; Adolphe Merkle Institute University of Fribourg Fribourg Switzerland ; NCCR Bio‐inspired Materials University of Fribourg Fribourg Switzerland

Olivier, Yoann ; Laboratory For Computational Modelling of Functional Materials Namur Institute of Structured Matter University of Namur Belgium

Sluysmans, Damien ; Université de Liège - ULiège > Département de chimie (sciences)

^✱ These authors have contributed equally to this work.

Language :

English

Title :

Force Reveals Hidden Conformations and Dissociation Pathways in Individual π‐Interacting Dimers

Publication date :

02 June 2026

Journal title :

Angewandte Chemie International Edition

ISSN :

1433-7851

eISSN :

1521-3773

Publisher :

Wiley

Peer reviewed :

Peer Reviewed verified by ORBi

Additional URL :

https://onlinelibrary.wiley.com/doi/pdf/10.1002/anie.9238302

Available on ORBi :

since 03 June 2026

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