New disc-shaped triarylamino-1,3,5-triazines with heteroaromatic central cores

New disc-shaped triarylamino-1,3,5-triazines were prepared by reaction of cyanuric chloride with two-fold alkoxy substituted anilines. Each of the triarylmelamines exhibits an enantiotropic mesophase. X-ray investigations reveal the formation of columnar liquid crystalline structures with either a hexagonal or a rectangular lattice. The lattice parameters, as well as the intracolumnar ordering, depend on the length of the flexible lateral side chains. The new melamines form Langmuir monolayers at the air/water interface due to their amphiphilic nature. The monolayer organization is characterized by a side-on arrangement of the molecules. The polar central molecular parts lie flat on the water, whereas the lateral alkyl chains are oriented perpendicular to the water surface.