Ion‐Pair‐Based Assemblies Comprising Pyrrole–Pyrazole Hybrids

Abstract

Modified 3,5-dipyrrolylpyrazole (DPP) derivatives in their protonated form produce planar [2+2]-type complexes with trifluoroacetate (TFA) ions. These complexes serve as constituent components of ion-pair-based assemblies. An essential strategy for the construction of dimension-controlled organized structures based on these [2+2]-type complexes is the introduction of aryl rings bearing long alkyl chains, which enables the formation of 2D patterns at interfaces, supramolecular gels, and mesophases.

Ionic Liquid Crystals: Versatile Materials

“…280,359,548 Interestingly, while [C 12 C 12 im]-[NTf 2 ] does not show any enantiotropic LC phase (Table S2), 553,563 The Maeda group reported on protonated 3,5-dipyrrolylpyrazole derivatives (354-R 3 and 355) that form planar [2+2]-type ion-pair complexes with bridging [CF 3 COO] − anions through hydrogen bonding (Figure S21). 64,974 Compounds 354-R 3 (R 3 = H or F) show thermotropic columnar and cubic mesomorphism, and form supramolecular gels, as well as 2D patterns on a HOPG substrate. The hole mobility of 354-R 3 was measured in the solid state at room temperature by FP-TRMC, and it is higher than that of their nonprotonated precursors.…”

“…Multicontinuous cubic phases (Cub V ) consist of interpenetrating, infinite, periodic 3D molecular networks (the surfaces obtained by connecting all of the midway points between the networks are referred to as “infinite periodic minimal surfaces”). Thermotropic Cub V mesophases of Ia 3̅ d , Im 3̅ m , Pn 3̅ m , and Pm 3̅ m symmetry, and thermotropic CubI mesophases of Pm 3̅ n , Im 3̅ m , Pm 3̅ m and Fm 3̅ m symmetry have been found to date. ,− Because of the high symmetry of cubic mesophases, and contrary to most other LC mesophases, the cubic phases are optically isotropic. Essentially no defect texture is observed by POM.…”

Self-Associating Curved π-Electronic Systems with Electron-Donating and Hydrogen-Bonding Properties

“…Meanwhile, acyclic pyrrole-based π-electronic molecules form various assemblies depending on their geometries and electronic states, as seen in, for example, solid-state packing structures. Thus, far, dipyrrolyl-substituted π-electronic systems with bridged pyrazole and the 1,3-propanedione enolate–boron complex have been prepared from dipyrrol-2-yl-1,3-propanediones, exhibiting anion binding and resulting ion-pairing assemblies. , The facile conversion of 1,3-diketone by reaction with appropriate diamines would afford curved π-electronic systems with nonplanar heterocycles. In this study, curved π-electronic molecules, dipyrrolylbenzodiazepines (dpbs), were synthesized as seven-membered heterocycle-based dipyrrolyl derivatives (Figure ).…”

Tetra- and Octapyrroles Synthesized from Confusion and Fusion Approaches

“…As a class of promising intermediates in synthetic porphyrin chemistry, and coordinating ligands for constructing supramolecular assemblies and sensing various ions, linear oligopyrroles with pyrrole units interconnected at the α positions have attracted extensive attentions in recent years . Tetrapyrrolic bilanes are unique members of linear oligopyrroles because they contain the same numbers of pyrrolic units as porphyrins and they have been used for the syntheses of porphyrins and their analogues, such as corroles, through acid-catalyzed condensation or oxidative cyclization. , In these cases, terminal pyrrole units are interconnected at the free α positions.…”