Synthesis of Fullerodendrons with an Ammonium Unit at the Focal Point and Their Cooperative Self-Assembly on a Fluorescent Ditopic Crown Ether Receptor

• Published in: Chemistry : a European journal 2006-04, Vol.12 (12), p.3365-3373
• Main Authors: Nierengarten, Jean-François, Hahn, Uwe, Trabolsi, Ali, Herschbach, Haiko, Cardinali, François, Elhabiri, Mourad, Leize, Emmanuelle, Van Dorsselaer, Alain, Albrecht-Gary, Anne-Marie
• Format: Article
• Language: English
• Subjects: cooperative phenomena; crown compounds; Crown Ethers - chemistry; dendrimers; fullerenes; Fullerenes - chemistry; Photochemistry; Quaternary Ammonium Compounds - chemistry; Spectrometry, Mass, Electrospray Ionization; supramolecular chemistry
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200501238

Dendritic branches with 1, 2, or 4 peripheral fullerene subunits and an ammonium function at the focal point have been prepared. Their ability to form self‐assembled dendritic structures with oligophenylenevinylene receptors bearing one or two crown ether moieties has been evidenced by ES‐MS studies for the first time. These supramolecular complexes are multicomponent photoactive devices in which the emission of the central receptor is dramatically quenched by the fullerene units. This new property resulting from the association of the different molecular subunits allowed detailed investigations of the self‐assembly process by means of fluorescence titrations. The binding studies have revealed positive cooperative effects for the assembly of the fullerodendrimers with the ditopic receptor. Interestingly, the stability of the supramolecular 2:1 structures increases as the size of the dendritic unit increases. This positive dendritic effect has been explained by the larger number of possible intramolecular fullerene–fullerene interactions between the two dendritic guests when the number of fullerene subunits is increased. Branching out! Dendritic branches with peripheral C60 subunits and an ammonium function at the focal point have been prepared and self‐assembled on fluorescent receptors that bear one or two crown ether moieties (see figure). The presence of the fullerene subunits in the dendritic guests is not only important for their ability to act as energy acceptors, but they are also at the origin of a positive cooperative effect that increases the stability of the 2:1 complexes.