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)

An endohedral metallofullerene, La-2@C-80, is covalently linked to the strong electron acceptor 11,11,12,12-tetracyano-9,10-antha-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 (i.e., pi-pi* centered at La-2@C-80) the unprecedented formation of the (La-2@C-80)(center dot+)-(TCAQ)(center dot-) radical ion pair state eevolves in nonpolar and polar media with a quantum efficiency of 33%.