3D and 2D supramolecular assemblies and thermotropic behaviour of a carbo-benzenic mesogen
Résumé
Hexaalkoxy-di( phenylethynyl)-tetraphenyl-carbo-benzenes bearing six CnH2n+1 aliphatic chains (n = 12, 18) have been synthesized and characterized, including by single crystal XRD analysis. For n = 12, a liquid crystal behaviour was observed in the range of 109-130 degrees C. DSC, POM and PXRD analyses evidenced a rectangular columnar mesophase at 115 degrees C. The determined 3D lattice constants are consistent with 2D STM images of the so-called "carbo-mesogen'' deposited on an HOPG surface.