Nematic self-organization of regioselectively polyfunctionalized fullerene†
The attempt to elaborate organic materials at the nanoscale has attracted broad attention in the last few years. Here, we report the synthesis and characterization of new polypedic organic materials possessing the fullerene as the three-dimensional rigid scaffold. High molecular weight hexakisadducts with different symmetries were obtained in 40 to 60% yield through modulations of the A. Hirsch's and B. Kraütler's methodologies. Such a regioselective grafting of side-connected malonates on C60 put in evidence that not only the size but also the nature of the malonate influences very strongly the optimal reaction conditions to the preparation of multiadducts with very good yields. Characterization was complemented by an investigation of their thermotropic behaviour. Starting from non-mesogenic precursors, the 3D organization stemming from the regioselective polyfunctionalization of the carbon nanosphere allowed highlighting an original nematic self-organization (no literature equivalent) which could be partially oriented under a magnetic field at room temperature.