Volume 2 Issue 9, September 2023

Renana Gershoni-Poranne, Branco Weiss fellow and assistant professor at the Technion - Israel Institute of Technology, talks to Nature Synthesis about probing aromatic molecules with computational tools.

Birgit Esser, Full Professor of Organic Chemistry at Ulm University, talks to Nature Synthesis about the challenges of synthesizing conjugated nanohoops and other aromatic systems.

Aromatic molecules with multiple one-half twists are synthesized using different precursors and synthetic routes. The pseudo-helicoidal structural chirality of these molecules and the loop of the twisted π-electronic structure fully overlap, thus giving rise to enhanced chiroptical responses.

Stereocontrolled radical polymerizations are elusive, owing to the difficulty of controlling facial addition at a propagating planar, sp² radical chain end. Now, cobalt–porphyrin initiators are reported that enable the preparation of well-defined, highly isotactic polyacrylamides at low Lewis acid loading.

The synthesis of polyacene is hampered by low solubility and instability of the product as well as side reactions. Now, polyacene is synthesized by polymerizing monomers confined in a metal–organic framework.

A hydrogen-bonded organic framework reversibly forms crystalline and amorphous phases in solid and liquid states, enabling solution processability for the polymer-based framework.

The electrocatalytic oxygen evolution reaction (OER) balances the hydrogen evolution reaction when splitting water into hydrogen and oxygen. This review highlights the need for new theory, electrochemistry and operando spectroscopy to enable knowledge-driven synthesis of new OER electrocatalysts.

Synthesizing superstructures with precisely controlled nanoscale building blocks is challenging. Here the assembly of superstructures is reported from atomically precise Ce₂₄O₂₈(OH)₈ and other rare-earth metal-oxide nanoclusters and their multicomponent combinations. A high-temperature ligand-switching mechanism controls the self-assembly.

Graphene-like molecules with a zigzag periphery are synthetically challenging. Now, a programmable zigzag π-extension strategy to rapidly assemble graphene-like molecules is reported based on rhodium-catalysed sequential C2–H and C8–H activation-annulation of naphthalene ketones, using acetylenedicarboxylates as the C2 insertion unit.

Elongation of acenes with linearly fused benzene rings is a synthetic challenge. Now, the use of a metal–organic framework enables the synthesis of polymeric precursors, which undergo thermal transformation to form polyacenes.

The backbone stereoregularity that dictates a broad range of polymer properties cannot be readily controlled in radical polymerizations. Now, bimetallic catalysts containing covalently bridged rare earth and cobalt complexes enable stereocontrolled living radical polymerization of acrylamides tethered with diverse polar and ionic pendant groups.

The synthesis of ionogel membranes is challenging to control. Now, a general strategy is developed for the layer-by-layer exfoliation of 2D ionogel membranes through controlled solvent-induced supramolecular self-assembly. This strategy enables the rapid and scalable fabrication of ionogels with designable shapes, controllable thicknesses, high ionic conductivity and promising applications.

The fabrication of organic polymers in single-crystal form is challenging. Here a rare single-crystal porous polymer with solution processability is synthesized by combining a one-dimensional chain structure, dynamic covalent bonds and various intermolecular interactions. This polymer is used as a coating on fabric for ammonia capture.

The synthesis of topological molecular carbons with persistent chirality is challenging. Here, a triply twisted Möbius carbon nanobelt was synthesized and its two enantiomers were isolated, showing a large absorption dissymmetry factor.

Twisted aromatic belts provide unique topologies and complex chiralities for nanocarbon materials. Now, rhodium-catalysed asymmetric [2 + 2 + 2] cycloadditions enable the stereoselective synthesis of doubly, triply and quadruply twisted aromatic belts.