exTTF as a building block for fullerene receptors. unexpected solvent-dependent positive homotropic cooperativity

Emilio M Pérez; Luis Sanchez; Gustavo Fernandez; Nazario Martín

doi:10.1021/ja0621389

exTTF as a building block for fullerene receptors. unexpected solvent-dependent positive homotropic cooperativity

J Am Chem Soc. 2006 Jun 7;128(22):7172-3. doi: 10.1021/ja0621389.

Authors

Emilio M Pérez¹, Luis Sanchez, Gustavo Fernandez, Nazario Martín

Affiliation

¹ Departamento de Química Organica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain.

PMID: 16734465
DOI: 10.1021/ja0621389

Abstract

The first exTTF-based receptor for molecular recognition of fullerene is described. Unexpectedly, the receptor shows completely different binding modes in chlorobenzene and CHCl3/CS2 mixtures. In the aromatic solvent, the receptor binds C60 in a noncooperative fashion (nH = 1) with a Kassoc = (2.98 +/- 0.12) x 103 M-1, whereas in CHCl3/CS2 mixtures, it shows a marked positive homotropic cooperative effect (nH = 2.7) toward binding of C60, with an apparent binding constant of (3.56 +/- 0.16) x 103 M-1. The unique solvent-switchable behavior of our receptor might find use in the controlled self-assembly of exTTF-C60 donor-acceptor ensembles.