title: exTTF as a building block for fullerene receptors. unexpected solvent-dependent positive homotropic cooperativity.
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.
authors.affiliation: Departamento de Química Organica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain.
authors.forename: Emilio M
authors.initials: EM
authors.lastname: Pérez
authors.forename: Luis
authors.initials: L
authors.lastname: Sanchez
authors.forename: Gustavo
authors.initials: G
authors.lastname: Fernandez
authors.forename: Nazario
authors.initials: N
authors.lastname: Martín