Ionic Self‐Assembly of Ammonium‐Based Amphiphiles and Negatively Charged Bodipy and Porphyrin Luminophores

Abstract

This paper describes the synthesis of wedge-shaped, charged amphiphilic molecules bearing an ammonium group at the tip that are able to organize negatively charged luminophores through an ionic self-assembly (ISA) process into discotic liquid-crystalline materials. For this purpose, two negatively charged luminescent molecules, 4,4-difluoro-1,3,5,7,8-pentamethyl-2,6-disulfonato-4-bora-3a,4a-diaza-s-indacene (sulfobodipy(2-)) and tetrakis(4-sulfonatophenyl)porphyrin (TPPS(4-)), were tested. The neutral luminescent complexes obtained through ISA form columnar mesophases that display hexagonal symmetry. Molecular modeling provides a structural description of the discotic mesophases in which the anionic luminophores are stacked in the middle of the disks. The key role of the amide linkage in the stabilization of the columnar architecture was probed by using infrared spectroscopy. Fluorescence microscopy has been used to show that the complexes are luminescent in both the solid and mesomorphic states.

Probing magnetic interactions in columnar phases of a paramagnetic gold dithiolene complex

“…26 With one molecule per plateau (Z ¼ 1), the stacking periodicity thus found is 3.59 A in excellent agreement with the value derived from the wide-angle diffuse halo. This value indicates that each slide forming the column is formed by one [Au(OC 12 ) 8 ] molecule.…”

Self-Assembly of Bodipy-Derived Extended π-Systems

“…42,43 However, a complete loss of liquid crystalline (LC) property was observed when ionic complex prepared from 2 and imidazolium cation functionalized with photopolymerizable acrylate terminated trialkoxy benzyl moiety (6). 43 In the thin film state, this ionic complex was found to be easily polymerizable under milder conditions, which allowed writing of information on the fixed polymeric film using a photomask.…”

Ionic Liquid Crystals Formed by Self‐Assembly around an Anionic Anthracene Core

“…This implies that each disc, generating columns by stacking, is formed by two complexes (Figure 8). [14] The ionic groups are located in the centre of the disc and the peripheral chains surround the central ionic region. In this way, optimal microsegregation between the aliphatic and polar parts inside a disc is ensured.…”

“…The aim of this work was to organise a luminescent p-conjugated fragment into columnar liquid-crystalline materials. For this purpose, commercially available double-tailed ammonium surfactants and synthetic wedge-shaped amphiphilic molecules with ammonium groups at the tip, [14] known to be able to organise charged molecules into mesogenic materials through ISA processes, were selected as countercations. A series of imidazolium cations carrying trialkoxyphenyl moieties of various chain lengths, described earlier by Kato and co-workers, [15] was also selected, as these molecules are known to form columnar mesophases over wide temperature ranges including room temperature.…”