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Supramolecular chirality is the major branch of supramolecular chemistry, which not only plays important roles in biological processes but also in synthetically designed aggregated systems. To understand the complex processing of biological systems, the only way is to design supramolecular chiral ensembles that mimic natural biomolecules such as Deoxyribonucleic acid (DNA), Ribonucleic acid (RNA), amino acids, etc. In addition, chiral systems and self‐assemblies as molecular motifs with breaking spatial inversion symmetry have been regarded as key substances in electronics and spintronics as well as in fundamental chemistry and physics. Here, in this review, our major concern is understanding modulation in spatial arrangements and packing modes under the impact of any external stimuli, which results in tailoring the handedness of resulted supramolecular chiral superstructures. We, in this review, highlighted the role of external stimuli such as solvent, chemical additives, photo exposure, etc. in altering the supramolecular chirality for their future utility as “active switches” in optoelectronic and spintronic devices and applications. [ABSTRACT FROM AUTHOR]

This document provides a concise summary of an article discussing the synthesis and analysis of 5,7,8,10-tetraphenyl-1,14-dianilinotripyrrins. The study explores the structural changes and properties of these compounds in response to different environments and substituents. The article provides detailed information on the synthesis, structures, and spectroscopic analysis of the synthesized compounds. The findings suggest potential applications as near-infrared emitters and further research on the photophysical dynamics of tripyrrins is ongoing. The document also acknowledges funding support and provides access to additional supporting information online. [Extracted from the article]

A quasi‐planar N, N, N',N'‐tetraphenyl‐para‐phenylenediamine, where all the phenyl rings are tethered by four oxygen atoms to embed quasi‐planar triphenylamine moieties into the molecular skeleton, was prepared and characterized to evaluate the impact by incorporating the structural rigidity. The monocationic and dicationic species could be selectively generated, depending on the type of oxidizing agents used. Spectroscopic and X‐ray diffraction analyses revealed the radical cation was in a unique charge/spin delocalized class III mixed‐valence state due to an exquisite balance between the electronic effect by the oxygen‐bridges and the rigidity of molecular framework. [ABSTRACT FROM AUTHOR]

A benzannulated double aza[9]helicene 1 was successfully synthesized via a one‐pot oxidative fusion reaction. 1 was derivatized to N‐alkylated double aza[9]helicene 1‐Et and 1‐Bu, whose structures were determined by X‐ray diffraction analysis. 1‐Et and 1‐Bu exhibited red‐shifted absorption and fluorescence spectra compared to single aza[9]helicene. The double aza[9]helicenes were expected to have two different conformers. Consistent with solid‐state structure, the chiral‐isomer was estimated to be more stable by 16 kcal/mol relative to meso‐isomer. Indeed, enantiomers of 1‐Et and 1‐Bu were optically resolved by HPLC and showed mirror‐imaged CD and CPL spectra with the CPL brightness up to 19.2 M−1cm−1 for 1‐Bu. [ABSTRACT FROM AUTHOR]

Metal complexation and peripheral modifications of thiaporphyrins have been investigated for preparing polarized π-electronic cations with anion-dependent ion-pairing assembling modes, including charge-segregated structures exhibiting electric conductive properties. [ABSTRACT FROM AUTHOR]

A highly condensed packing structure with π-molecules is important to achieve high carrier transport properties. To realize condensed π-molecular arrangements, we focused on electrostatic crystal lattices consisting of cation–anion pairs and further designed an anionic N,N′-bis(ethyl sulfonate)-naphthalenediimide (ESNDI2−), which introduces structural flexibility at two –C2H4SO3− side arms. The size of the counter cation (M+) was varied from Na+, K+, Rb+, and Cs+ to design a precise crystal lattice of (M+)2(ESNDI2−)·(H2O)n salts, which is divided into hydrated salts (M+ = Na+ and K+) and anhydrous salts (M+ = K+, Rb+, and Cs+). Salt for M+ = K+ is a boundary between hydrated and anhydrous crystals, and exhibited reversible H2O adsorption–desorption behavior at 298 K. In addition, the K+ salts showed transient conductivity (φΣμ) switching behavior associated with the H2O adsorption–desorption cycle. The anhydrous salts for M+ = K+, Rb+, and Cs+ had isomorphous crystal structures, with the appearance of a two-dimensional (2D) herringbone arrangement in ESNDI2−. The condensed packing arrangement and highest φΣμ value were observed in (Rb+)2(ESNDI2−) salt. In these anhydrous salts, crystalline domains were easily formed using the simple casting method on the substrate surface. The temperature- and frequency-dependence of the dielectric constant indicated the presence of thermally induced structural fluctuations in these ionic crystal lattices. In hydrated crystals, thermal motions of Na+, K+, and H2O were dominant, whereas thermal fluctuations in the rigid M+⋯−O3S– Coulomb lattice were observed in anhydrous crystals as Debye-type relaxation. Precise structural control of the electrostatic crystal lattice determines the optimization conditions for achieving condensed π-molecular arrangement. [ABSTRACT FROM AUTHOR]

Amplified spontaneous emission (ASE) is considered to be a primary indication of optical gain in active media without an external resonator. Molecular materials with ASE are expected to be one of the suitable light sources for specific applications such as optical coherent tomography owing to their low coherence and flexible tunability. Concentration quenching of emissive excited states has been a critical issue to boost the quantum efficiency of molecular materials in their condensed phases. The rod-like design of molecules with excited state intramolecular proton transfer (ESIPT) has been demonstrated to overcome this issue in highly-concentrated molecularly-doped systems, as represented by C4alkyne-HBT (2-(4-(1-hexynyl)-2-hydroxyphenyl)-benzothiazole). We designed an ESIPT molecule-doped liquid crystalline (LC) system for optical amplification via the ASE regime with its wide tunability of emission intensity. Detailed ASE behaviour and optical gain of a LC blend of C4alkyne-HBT and 4-pentyl-4′-cyano biphenyl (5CB) was evaluated to afford a maximum optical gain of 16.5 cm−1 with an estimated ASE threshold of optical pumping at 0.6–0.7 mJ cm−2. Although most ASE studies focus on homogeneous solutions, solids, or crystalline states, ASE from a soft-flexible LC phase is quite limited and advantageous for the design of an external optical resonator/cavity structure. Optical excitation parallel and perpendicular to the director resulted in the strong modulation of the ASE. By using the benefits of a LC phase, the ASE was actively modulated under the external electric field by the reorientation of the molecular dipole moment. [ABSTRACT FROM AUTHOR]