Synthesis, optical properties and lamellar self-organization of new N,N′,N″-trialkyl-triazatriangulenium tetrafluoroborate salts

• Synthesis of new triazatriangulenium dyes.
• Homeotropic aligned discotic dyes in a lamellar structure.
• Optical properties of new TATA dyes in solution and solid state.

Here we report the synthesis of six new N,N′,N″-trialkyl-triazatriangulenium (R3-TATA+) tetrafluoroborate salts with ether functions in their side chains. Solution and solid-state optical properties of the R3-TATA+ salts were investigated to elucidate the influence of the side chain heteroatoms on the electronic structure of the chromophore. Structural studies of spin-cast thin films of nine different R3-TATA+ BF4− salts showed, for all derivatives, formation of a rare structure with homeotropic aligned discotic dyes in a lamellar structure. In the lamellar structure, layers of the charged discotic TATA+ dyes and their counter ions are separated by the perpendicularly oriented alkyl chains. In all cases, it was found that simple spin-casting gave films with macroscopic alignment of the lamellar structure parallel to the substrate. Formation of the lamellar structure, for all the R3-TATA+ BF4− salts, both with branched and linear side chains, highlight the robustness of this self-organizing motif.