DRAMATIC STABILIZATION OF A HEXAGONAL COLUMNAR MESOPHASE GENERATED FROM SUPRAMOLECULAR AND MACROMOLECULAR COLUMNS BY THE SEMIFLUORINATION OF THE ALKYL-GROUPS OF THEIR TAPERED BUILDING-BLOCKS

The tapered building blocks 3,4,5-tris[(4-(n-decan-1-yloxy)benzyl)oxy] benzoic acid (8-10/0), 3,4,5-tris 0,10,10-tridecafluoro-n-decan-1-yl)o xy)benzyl)oxy] benzoic acid (8-4/6), 2-{2-[2-(2-hydroxyethoxy)ethoxy]e thoxy}ethyl 3,4,5-tris[(4-(n-decan-1-yloxy)benzyl)oxy]benzoate (11-10/ 0), 2-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}ethyl 0,10,10-tridecafluoro -n-decan-1-yl)oxy)benzyl)oxy] benzoate (11-4/6), 2-{2-[2-(2-hydroxyeth oxy)ethoxy]ethoxy}ethyl 3,4,5-tris(n-decan-1-yloxy)benzoate (18-10/0), 2{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}ethyl 9,10,10,10-tridecafluoro- n-decan-1-yl)oxy)benzoate (18-4/6), the methacrylates of 11-10/0 (12-1 0/0), 11-4/6 (12-4/6), 18-10/0 (19-10/0), and 18-4/6 (18-4/6), and the corresponding polymethacrylates 13-10/0, 13-4/6, 20-10/0, and 20-4/6 were synthesized and characterized. With the exception of 8-10/0 which forms a smectic mesophase, all other building blocks and polymers sel f-assemble into tubular supra: molecular architectures which generate hexagonal columnar (Phi(h)) mesophases. The fluorination of six out of the ten methylene units of the alkyl tails of these compounds induces a dramatic stabilization of their Phi(h). In the case when the parent hydrogenated compound (8-10/0) forms a lamellar smectic mesophase or only a crystalline phase (18-10/0), fluorination generates a Phi(h) me sophase.