Photophysics DOI: 10.1002/anie.201305536 A Strongly Emitting Liquid-Crystalline Derivative of Y 3 N@C 80 : Bright and Long-Lived Near-IR Luminescence from a Charge Transfer State** Kalman Toth, Jennifer K. Molloy, Micaela Matta, Benoît Heinrich, Daniel Guillon, Giacomo Bergamini, Francesco Zerbetto,* Bertrand Donnio,* Paola Ceroni,* and Delphine Felder-Flesch* Dedicated to Professor Maurizio Prato on the occasion of his 60th birthday Metal-containing fullerenes, and particularly trimetallic nitride template endohedral metallofullerenes (TNT- EMFs), [1] elicit increasing attention [2] not only for their fascinating structure and potential for stabilizing metallic nitrides, but also for their outstanding electronic and optical properties. TNT-EMFs are noteworthy electron acceptors. [3, 4] They also possess larger absorption coefficients than C 60 in the visible region, making them promising candidates for replacing the well-known phenyl C 61 butyric acid methyl ester (PCBM) in bulk heterojunction (BHJ) solar cells. [5] They could then be used as potential auxiliary materials for singlet- exciton dissociation at the donor–acceptor interfaces, provid- ing charge-transport pathways across the semiconducting layer. [6] Charge-carrier transport and light-emission efficien- cies are closely related to the molecular organization and degree of ordering, for example, that found in the thin film morphology (nanostructuration). It is widely recognized that self-organization by the formation of low-dimensional liquid- crystalline (LC) phases is a key strategy for controlling the ordering and structuring of organic semiconductors because it helps to reduce or even suppress defect formation. [7] Chemical functionalization of TNT-EMFs [8] appears therefore to be an original and promising approach for reaching self-organiza- tion and obtaining processable materials. Although a wide number of LC fullerenes have been studied since the early 90s, [9] none of these studies concern the TNT-EMF family. Herein, we report on the synthesis, functionalization, and characterization of the first TNT-EMF-based liquid crystal (1) and compare both mesomorphic and photophysical behaviors with the related C 60 counterpart (2), synthesized as a model compound (Scheme 1). Both fullerene entities (C 60 and Y 3 N@C 80 ) are chemically linked to two oligo(phenylene ethynylene) (OPE) arms, which determine the self-organizing and absorbing properties. Malonate bearing double OPE units (dOPE) or mono- brominated dOPE were reacted to the C 60 and Y 3 N@C 80 Scheme 1. Chemical structures of Y 3 N@C 80 -based (1) and C 60 -based (2) dyads and their common malonate intermediate dOPE. [*] Dr. K. Toth, Dr. B. Heinrich, Dr. D. Guillon, Dr. B. Donnio, Dr. D. Felder-Flesch Institut de Physique et Chimie des MatØriaux de Strasbourg UMR CNRS UdS 7504 23 rue du loess BP 43, 67034 Strasbourg Cedex 2 (France) E-mail: Bertrand.Donnio@ipcms.unistra.fr Delphine.Felder@ipcms.unistra.fr Dr. J.K. Molloy, M. Matta, Dr. G. Bergamini, Prof. F. Zerbetto, Prof. P. Ceroni Dipartimento di Chimica “G. Ciamician”, Universita’ di Bologna Via Selmi, 2, 40126 Bologna (Italy) E-mail: paola.ceroni@unibo.it francesco.zerbetto@unibo.it [**] This research is supported by the European Commission through grant agreement DENDREAMERS (ITN Marie Curie) n8215884 and ERC StG (PhotoSi, 278912). We are also grateful to the CNRS and the University of Strasbourg. Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/anie.201305536. A ngewandte Chemi e 12303 Angew. Chem. Int. Ed. 20,, 39, 12303 –12307  20, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim