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 [(4-((5,5,6,6,7,7,8,8,9,9,10,10,10-tridecafluoro-n-decan-1-yl)oxy)benzyl)oxy] benzoic acid (8-4/6), 2-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}ethyl 3,4,5-tris[(4-(n-decan-1-yloxy)benzyl)oxy]benzoate (11-10/0), 2-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}ethyl 3,4,5-tris[(4-((5,5,6,6,7,7,8,8,9,9,10,10,10-tridecafluoro-n-decan-1-yl)oxy)benzyl)oxy] benzoate (11-4/6), 2-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}ethyl 3,4,5-tris(n-decan-1-yloxy)benzoate (18-10/0), 2{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}ethyl 3,4,5-tris((5,5,6,6,7,7,8,8,9,9,10,10,10-tridecafluoro-n-decan-1-yl)oxy)benzoate (18-4/6), the methacrylates of 11-10/0 (12-10/0), 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 self-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) mesophase.