Supramolecular chemistry

Electrochemistry

Photochemistry

Ferrocene

Density functional theory

Molecule

Intermolecular force

Physical chemistry

Molecular tweezers

Organic chemistry

Computational chemistry

Crystallography

Dimer

Chemistry

Electrode

Fullerene

Carbazole

Tweezers

Journal of the American Chemical Society

We designed and synthesized molecular tweezers consisting of nitrogen-embedded buckybowl subunits. The judicious choice of the covalent linkers modulated their binding strength with C60 or C70 in solution. Titration studies by optical and 1H NMR analyses revealed a 1:1 composition of the resulting complexes. X-ray diffraction analysis elucidated their solid-state structures, in which two azabuckybowl units surround one fullerene molecule. The large association constants stabilize the complexes toward redox reactions and the purification process on silica-gel column chromatography. The linker enabled tuning of the cavity size for binding of fullerenes, achieving complementary fullerene hosts for C60 and C70: the carbazole-bridged dimer preferentially associates with C70 over C60, while the phenanthrene-bridged dimer interacts with C60 more strongly than C70. Electrochemical analysis in combination with density functional theory calculations indicated the existence of intermolecular charge-transfer interactions between the buckybowl units and the fullerenes. Nonlinear optical measurements showed that the two-photon absorption cross sections of the molecular tweezers are enhanced upon association with fullerenes.

Azabuckybowl-Based Molecular Tweezers as C<sub>60</sub> and C<sub>70</sub> Receptors

Azabuckybowl-Based Molecular Tweezers as C60 and C70 Receptors

Azabuckybowl-Based Molecular Tweezers as C₆₀ and C₇₀ Receptors