Synthesis and Self-Assembly of Novel s-Tetrazine-Based Gelator

The design, synthesis and self-assembly of new symmetrical 3,6-bis(4-(3,4,5-tris(dodecyloxy)benzoate)phenyl)-1,2,4,5-tetrazine were described. The novel gelator, sym-tetrazine, was prepared by addition reaction of 4-cyanophenol with hydrazine monohydrate followed by oxidation reaction to afford the corresponding 3,6-bis(4-hydroxyphenyl)-1,2,4,5-tetrazine which was then subjected to esterification reaction with 3,4,5-tris(dodecyloxy)benzoic acid. The chemical structure of the sym-tetrazine gelator was confirmed by elemental analysis, fourier-transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance (H-1- and C-13-NMR) spectral measurements. It was confirmed to exhibit relatively strong gelation ability to produce supramolecular assemblies in several polar alcoholic organic solvents, such as butanol, octanol, and 1,6-dihydroxyhexane. The - stacking and van der Waals mediated self-assembly of tetrazine-based organogelator were studied by scanning electron microscopy images of the xerogel to reveal that the obtained organogel consists of fibrillar aggregates. Investigation of FT-IR and concentration-dependent H-1-NMR spectra confirm that the intermolecular van der Waals interactions and - stacking were the key driving forces for self-assembly during gelation process of s-tetrazine molecules.