Extended π-conjugated systems are often insoluble, and their aggregation manner greatly affects their absorption spectra. This study produced a planar, soluble, and nonaggregated hexarylene-bisimide (HB) with appropriate substituents. The single-crystal X-ray structure of HB confirmed the planar molecular structure with small twist angles and the dimerization behavior of HB in the solid state. The concentration-dependent 1H NMR experiments in CDCl3 indicated that the association constant Kdimer is 4.6 × 103 M–1 at 298 K and ΔGdimer (298 K) = −20.8 kJ mol–1. The longest absorption of HB at the monomeric state exhibits a sharp and intense peak at 921 nm (ε = 230,000 M–1 cm–1, full width at half-maximum = 718 cm–1) in toluene. 75% of the absorption of HB above 400 nm appears in the near-infrared region, thus giving a practically colorless solution. Magnetic circular dichroism spectra of a series of oligorylene-bisimides reveal the predominant contribution of the linear polyene-like conjugation over the annulene-like conjugation for larger [n]oligorylene-bisimides.

Subtle electronic modifications of tailored amphiphilic azobenzene derivatives exhibit distinct cis-state half-lives despite similar activation barriers. The structural functionalization enables the ...

Förster resonance energy transfer (FRET) spectroscopy and microscopy are constantly expanding sensing techniques for analyzing biomolecular interactions. In addition to the biological recognition mole...

Electron beams evolved as important tools for modern technologies that construct and analyze nanoscale architectures. While electron–matter interactions at atomic and macro scales are well-studied, a ...

The analysis of the microstructure of supramolecular copolymers is difficult because of their dynamic character. Here, benzene-1,3,5-tricarboxamide (BTA) co-assemblies are analysed by ion mobility - ...

In this contribution, we apply our newly developed ball-milling operando platform, which combines Raman spectroscopy and thermal (IR) imaging, as well as acoustic and high-speed optical video recordings, to the synthesis and transformation of citric acid–isonicotinamide (1:2) cocrystal polymorphs in transparent PMMA jars. Particularly, we demonstrate how Raman, temperature, acoustic, and video data are complementary and enable detection and connection of chemical and physical events happening during ball-milling in a time-resolved manner. Importantly, we show that the formation of the three cocrystal polymorphs can be detected through acoustic analyses solely. Even more impressively, the meticulous analyses of the sound data allowed subtle polymorphic transitions to be perceived in operando mode when the Raman spectroscopy was not conclusive enough. Such changes in sound signatures are greatly linked to the beads’ motions in the milling jar. A new data analysis methodology of acoustic recordings is proposed through a combination of energetic and statistical approaches that simplifies the data analyses for potential users. The interpretation of the detected sound signals was further validated thanks to the high-speed videos recorded in synchronization with all other operando techniques. Finally, we broaden this acoustic methodology to opaque stainless-steel jars, showing the relevance of the acoustic analysis method for following polymorphic transformations of cocrystals, as well as pure substances, in any type of milling jar.

January 2025 marks one year since the launch of Nature Chemical Engineering.

Designing molecular receptors that bind anions in water is a significant challenge, and an even greater difficulty lies in using these receptors to remove anions from water without resorting to the ha...

Alt: a man in a suit speaks into a microphone and says, 'this is the start of your career'

Perpendicular nanochannel creation of two-dimensional (2D) nanostructures requires highly controlled anisotropic drilling processes of the entire structure via void formation. However, chemical approa...

Single-molecule electrical measurement of excited-state intramolecular proton transfer (ESIPT) photocycle reveals the dynamic process of photoconductance under different irradiation wavelengths. The ...

All chemists are familiar with the idea that, at equilibrium steady state, the relative concentrations of species present in a system are predicted by the corresponding equilibrium constants, which are related to the free energy differences between the system components. There is also no net flux between species, no matter how complicated the reaction network. Achieving and harnessing non-equilibrium steady states, by coupling a reaction network to a second spontaneous chemical process, has been the subject of work in several disciplines, including the operation of molecular motors, the assembly of supramolecular materials, and strategies in enantioselective catalysis. We juxtapose these linked fields to highlight their common features and challenges as well as some common misconceptions that may be serving to stymie progress.

Progress in chemistry has primarily been framed through inductive processes, leading to the frequent emergence of exceptions and unexpected reactivities. These anomalies─ranging from surprising reacti...

Commonly reported parameters such as time, rpm, and ball mass are often insufficient to replicate mechanochemical syntheses accurately. By demonstrating that reaction outcomes are tied to the cumulat....

Arylimines offer promise in dynamic-covalent materials due to their recyclability and ease of synthesis. However, their light-triggered E/Z isomerism has received little attention. This is attributed ...