Flavylium Salts: A Blooming Core for Bioinspired Ionic Liquid Crystals

Abstract

Thermotropic ionic liquid crystals based on the flavylium scaffold have been synthesized and studied for their structure‐properties relationship for the first time. The mesogens were probed by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and X‐ray diffraction (XRD). Low numbers of alkoxy side chains resulted in smectic (SmA) and lamello‐columnar (LamCol) phases, whereas higher substituted flavylium salts showed Colro as well as ordered and disordered columnar (Colho, Colhd) mesophases. Mesophase width ranged from 13 K to 220 K, giving access to room temperature liquid crystals. The optical properties of the synthesized compounds were probed towards absorption and emission properties. Strong absorption with maxima between 444 and 507 nm was observed, and some chromophores were highly emissive with quantum yields up to 99 %. Ultimately, mesogenic and dye properties were examined by temperature‐dependent emissive experiments in the solid state.

Current Topics in Ionic Liquid Crystals

“…For example, we took inspiration from the diverse family of anthocyanine plant dyes and developed flavylium ILCs, which showed a rich mesomorphism of SmA, Lam Col , Col r , Col h and even a unique re‐entrant I re phase (Scheme 4). [129] With increasing number of side chains columnar phases were favored at the expense of lamellar phases. Compound V‐Fla‐1 not only showed the highest quantum yield in solution (ϕ F 0.97) due to optimal charge delocalization and restriction of aryl rotation.…”

Metalated porphyrins as versatile visible light and NIR photoinitiators of polymerization

“…All compounds were characterized using the procedures and equipments ( 1 H and 13 C NMR, high resolution mass spectrometry (HRMS),…) reported elsewhere. [39] 4-Dodecylbenzaldehyde [40] , 2-dodecylbenzaldehyde [41] , 2,4-dibutoxybenzaldehyde [42] , 2butoxy-4-diethylaminobenzaldehyde [43] and 9-hexyl-9H-carbazole-3-carbaldehyde [44] , Porph_1 [45][46][47][48][49] , Porph_2 [50] , Porph_3 [51] , Porph_6 [52][53][54] , Porph_7 [55] , Porph_8 [56] , Fe-Porph_1 [57] were synthesized, as previously reported in the literature, without modification and in similar yields.…”

Self‐assembly and antistatic property of ionic liquid crystalline polymers

“… 13 . Ionic LC materials have been widely used in soft materials, 14,15 ion‐conducting materials, 16–19 and antimicrobial finishing materials 20 up to now. Furthermore, they will provide infinite possibilities for more applications in permanent antistatic agents similar to polymerized ionic liquid that are considered to be promising additives 21–24 .…”

“…Ionic liquid-crystalline (LC) materials combine the properties of ionic liquids (i.e., low melting point, high ionic conductivity, high dissociation, diverse structures) and liquid crystals (order fluidity, selfassembling ability, etc.). 13 Ionic LC materials have been widely used in soft materials, 14,15 ion-conducting materials, [16][17][18][19] and antimicrobial finishing materials 20 up to now. Furthermore, they will provide…”