title: An endohedral metallofullerene as a pure electron donor: intramolecular electron transfer in donor-acceptor conjugates of La2@C80 and 11,11,12,12-tetracyano-9,10-anthra-p-quinodimethane (TCAQ).
abstract: An endohedral metallofullerene, La(2)@C(80), is covalently linked to the strong electron acceptor 11,11,12,12-tetracyano-9,10-anthra-p-quinodimethane (TCAQ) by means of the Prato reaction, affording two different [5,6]-metallofulleropyrrolidines, namely 1a and 2a. 1a and 2a were isolated and fully characterized by means of MALDI-TOF mass, UV-vis-NIR absorption, and NMR spectroscopies. In addition, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) corroborated the unique redox character of 2a, that is, the presence of the electron-donating La(2)@C(80) and the electron-accepting TCAQ. Although a weak electronic coupling dictates the interactions between La(2)@C(80) and TCAQ in the ground state, time-resolved transient absorption experiments reveal that in the excited state (i.e., π-π* centered at La(2)@C(80)) the unprecedented formation of the (La(2)@C(80))(•+)-(TCAQ)(•-) radical ion pair state evolves in nonpolar and polar media with a quantum efficiency of 33%.
authors.affiliation: Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Takano
authors.forename: Shota
authors.initials: S
authors.lastname: Obuchi
authors.forename: Naomi
authors.initials: N
authors.lastname: Mizorogi
authors.forename: Raúl
authors.initials: R
authors.lastname: García
authors.forename: M Ángeles
authors.initials: MÁ
authors.lastname: Herranz
authors.forename: Marc
authors.initials: M
authors.lastname: Rudolf
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Guldi
authors.forename: Nazario
authors.initials: N
authors.lastname: Martín
authors.forename: Shigeru
authors.initials: S
authors.lastname: Nagase
authors.forename: Takeshi
authors.initials: T
authors.lastname: Akasaka
mesh_terms: D000880:Anthraquinones / Q000737:chemistry*; D004583:Electrons; D037741:Fullerenes / Q000737:chemistry*; D007811:Lanthanum / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: D000880:Anthraquinones; D037741:Fullerenes; C476518:tetracyanoanthraquinodimethane; D007811:Lanthanum