Figure 4
From: Energy transfer in supramolecular materials for new applications in photonics and electronics
(a) The presence of branched alkyl substituents can generate lamellar structures in which the fullerene moieties are in closed contact as evidenced by the X-ray diffraction (XRD) spectrum. Reproduced from reference Li et al.51 with permission of The Royal Society of Chemistry. (b) A similarly linear arrangement of fullerenes can also be obtained by designed hydrogen-bonding (H-B) interactions as observed in the crystal structure of a fullerene–barbiturate derivative in which energy transfer is particularly efficient. Reproduced with permission from reference Chu et al.52 Copyright 2010 the American Chemical Society. Upon irradiation, the polarized emission from this material undergoes a switch in direction (c) of ca 60° without any changes in the emission spectrum, intensity or lifetime. This process, termed photopolism, can be used to write information that can only be read out through the polarization component of the emission (d). Reproduced with permission from reference Raffy et al.53
