Methanofullerenes with mesogenic groups: Bulk properties and Langmuir films

New C-60 derivatives functionalized with mesogenic groups have been synthesized. Their behaviour at the nitrogen-water interface was investigated and appeared to depend on the nature of their functional group: if it contains a fluorinated chain, a stable monomolecular film is obtained; if not, then a multilayer organization is observed. In the bulk state, the structural organization of the methanofullerenes has been studied by polaried optical microscopy, DSC and X-ray diffraction experiments. At room temperature, a non-crystalline periodic structure is shown, and a phase transition leading to a viscous liquid state occurs when temperature increases. (C) 1997 Elsevier Science Ltd.