Premium
A Fullerene‐Based Molecular Torsion Balance for Investigating Noncovalent Interactions at the C 60 Surface
Author(s) -
Yamada Michio,
Narita Haruna,
Maeda Yutaka
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202005888
Subject(s) - non covalent interactions , conformational isomerism , fullerene , chemistry , intramolecular force , dihedral angle , computational chemistry , torsion spring , biphenyl , chemical physics , crystallography , stereochemistry , molecule , organic chemistry , hydrogen bond , physics , classical mechanics
To investigate the nature and strength of noncovalent interactions at the fullerene surface, molecular torsion balances consisting of C 60 and organic moieties connected through a biphenyl linkage were synthesized. NMR and computational studies show that the unimolecular system remains in equilibrium between well‐defined folded and unfolded conformers owing to restricted rotation around the biphenyl C−C bond. The energy differences between the two conformers depend on the substituents and is ascribed to differences in the intramolecular noncovalent interactions between the organic moieties and the fullerene surface. Fullerenes favor interacting with the π‐faces of benzenes bearing electron‐donating substituents. The correlation between the folding free energies and corresponding Hammett constants of the substituents in the arene‐containing torsion balances reflects the contributions of the electrostatic interactions and dispersion force to face‐to‐face arene–fullerene interactions.