Perspectives

Mechanochemistry is the science of inducing a chemical reaction through the application of mechanical force. This Perspective focuses on combining traditional mechanochemistry with different energy inputs — heat, light, sound or electrical impulses — to advance mechanochemical synthesis.

Endergonic photocatalysis enables the catalytic and atom-economic synthesis of products with higher free energies than reactants. This Perspective highlights current progress in endergonic photocatalysis by summarizing the energetics of these reactions and points out the industrial potential of such processes.

Studies employing machine-learning (ML) tools in the chemical sciences often report their evaluations in a heterogeneous way. The evaluation guidelines provided in this Perspective should enable more rigorous ML reporting.

In this Perspective, a vision of a fully reconfigurable microfluidic device that can change its shape and function dynamically is outlined. Reconfigurable microfluidic platforms can enable new functionalities, which have the potential to go beyond the reach of current lab-on-a-chip systems.

Microcrystal electron diffraction (MicroED) can determine the structure of proteins from crystals that are orders of magnitude smaller than those used by X-ray methods. Here, the application of MicroED to protein–ligand complexes is reviewed.

We propose that life originated in spontaneously formed catalytic lipid micelles. Accumulating experimental evidence shows that such micelles undergo compositional autocatalytic reproduction. Lipid-first constitutes a parsimonious alternative to the RNA-first scenario.

Reversible addition–fragmentation chain-transfer (RAFT) polymerization and atom transfer radical polymerization (ATRP) are evaluated in terms of their mechanistic strengths and weaknesses, versatility and latest synthetic advances.

Although a stalwart in materials science, electron diffraction has only recently become popular for characterizing molecular structures. This Perspective describes practical aspects of the method, which affords complementary information to X-ray and neutron diffraction.

Implementing effective chemomechanical coupling in the microscopic world is challenging. This Perspective describes recent advances of chemically-powered swimming or diffusion of objects on the molecular scale, nanoscale and microscale.

Understanding the relationship between reaction rate and thermodynamic driving force is central to developing efficient catalysts. This Perspective describes this relationship and the conditions that can give rise to reversible catalysis, which is relevant to energy conversions of fuels and motor proteins alike.

Theoretical models of clusters that account for molecular symmetry offer guidelines for their design. This Perspective describes the models and how we can synthesize the clusters thus designed.

Affinity selection-mass spectrometry enables rapid screening of compound mixtures against a specific biomolecular target. This assay lets us identify ligands irrespective of their binding site and is amenable to the discovery of novel drugs.

Bimetallic complexes are fertile territory for investigating metal–metal cooperativity. This Perspective highlights how complexes with two proximal metals have tunable features of relevance to bond activation, catalysis and unprecedented reactivity.

This Perspective discusses the prospects of assembling multiple molecular machines within ordered frameworks, with the goal of producing artificial molecular factories in which molecular motions are coupled, synchronized and amplified across multiple length scales, leading to robust and stimuli-responsive solids.

Iron–sulfur enzymes catalyse multielectron redox reactions in nature. This Perspective describes the in vitro methodologies by which we study these enzyme biosyntheses and compares the way in which different active sites are constructed.

Metal–ligand complexes undergo diverse charge-transfer processes when stimulated by light or electric fields. This Perspective describes how these processes can be exploited in photosensitizers, luminophores and resistive memory materials.

Molecular design and synthesis, from small molecules to supramolecular assemblies, combined with new spectroscopic probes of quantum coherence and theoretical modelling, offer a broad range of possibilities to realize practical quantum information science applications in computing, communications and sensing.

As the International Year of the Periodic Table came to an end in 2019, the authors reflect on the chemistry and physics that drive the periodic table of the elements. This includes aspects of periodic trends, relativistic electronic-structure theory, nuclear-structure theory and the astrophysical origin of the elements.

Machine-learning techniques have enabled, among many other applications, the exploration of molecular properties throughout chemical space. The specific development of quantum-based approaches in machine learning can now help us unravel new chemical insights.

High-resolution mass spectrometry has unrivalled power to analyse individual components of ensembles, rather than ensembles as a whole. This Perspective describes recent advances in the mass spectrometry of synthetic polymers, as well as the limitations of present methods and possible strategies to overcome them.