Perspectives

One-pot tandem reactions are attractive for both waste and time reduction, but can also enable transformations otherwise unobtainable in single-step processes. This Perspective covers recent advances in orthogonal tandem catalysis, while introducing the concept of thermodynamically leveraging multiple catalytic systems together to perform challenging transformations.

New synthetic routes to porous materials can be developed by taking advantage of a solid's weaknesses. This approach can lead to new products that break the rules of what is currently feasible.

Biological systems have evolved sophisticated machinery to assemble polymeric receptors capable of molecular recognition. Although such precise levels of structural control are currently inaccessible to chemists, impressive progress has been made towards the realization of wholly synthetic analogues of antibodies and other proteins. Protein structure from H. Li et al. Biochemistry 33, 11734–11744 (1994); © American Chemical Society.

RNA can carry information, self-replicate and catalyse reactions, and so is often included in scenarios for the origin of life, but was it the first self-replicator? This Perspective considers the question of whether simpler polymer structures could have encoded early life, and discusses how to seek them out.

Single-molecule and -particle fluorescence microscopy — traditionally applied to biophysical studies — has recently been used to gain insight into chemical systems. Still at its nascent stage, this approach presents great opportunities for the chemistry community through the observation of chemical reactions and their mechanisms as typically depicted in textbooks: molecule by molecule.

The reduction of N₂ by iron and molybdenum complexes is a rapidly moving field. This Perspective discusses the key advances in the past two years. The recent discovery of carbide at the centre of the iron-molybdenum cofactor of nitrogenase is also described, along with the most compelling areas for continued research.

Over the past decade, C–H bond activation has progressively become a well-established synthetic tool. An increased scope and understanding of this transformation has seen it being used in a wide range of contexts, not only in traditional organic synthesis, but also in late-stage diversification strategies for organic materials and biologically active molecules.

Although the molecular formula gives valuable information on the properties of isolated molecules or conjugated polymers, it fails to accurately predict their collective behaviour in the solid state. This Perspective highlights the importance of organization across multiple length scales on the optical and electronic properties of organic semiconductors, and how device performances poorly reflect the capabilities of a given material.

This Perspective discusses contemporary ideas for enzymatic reactions that invoke a role for fast 'promoting' (or 'compressive') motions or vibrations that, in principle, can facilitate enzyme-catalysed reactions. With an emphasis on hydrogen-transfer reactions, experimental, theoretical and computational approaches that have lent evidence to this controversial hypothesis are discussed.

Enzyme-catalysed reactions can involve significant quantum tunnelling and show kinetic isotope effects with complex temperature dependences. In this Perspective, reaction dynamics and enzyme catalysis are linked to transition-state-theory frameworks. It is shown that a multi-state model using standard transition-state theory can account for complex experimental data without invoking a role for enzyme dynamics.

Contemporary macromolecular chemistry and physics offer interesting options for making, characterizing and manipulating single polymer chains. Although it is not yet possible to emulate the structural control and functional ability of biopolymers, recent advances have opened up interesting avenues for applications of these synthetic systems in microelectronics, photovoltaics, catalysis and biotechnology.

Topological insulators — insulators or semiconductors with metallic states present at their boundaries — are the 'rising stars' of condensed-matter physics. This Perspective introduces these materials and their properties, and looks at the challenges and opportunities the community faces.

When cells interact with an artificial surface, the result is a rapidly evolving and complex interface. This Perspective discusses how expressing the properties of both the cell and the substrate in chemical terms can aid in future material design. We also explore the importance of using multifunctional surfaces with quantitative, dynamic capabilities.

The efficient engineering of nanostructures with semiconducting properties is vital to the development of organic electronics. This Perspective discusses a variety of techniques for fabricating such macromolecules, including graphene carving, the stimulus-induced synthesis of conjugated polymers and surface-assisted synthesis, and considers their potential for reproducing chemically and spatially precise molecular arrangements, that is 'molecular blueprints'.

Recently, individual organic molecules have been imaged with atomic resolution using non-contact atomic force microscopy with functionalized tips and scanning tunnelling hydrogen microscopy. The resulting applications of these techniques and further improvements of ultra-high spatially resolved molecular investigations are discussed in this Perspective.

Phenalenyl — a triangular neutral radical consisting of three adjacent benzene rings — and π-conjugated derivatives based on the same motif, can be viewed as 'open-shell graphene fragments'. This Perspective discusses their electronic-spin structures, the properties that arise from their unpaired electrons, and highlights their potential applications for molecular spin devices.

Principles based on overlaps and interactions between bonding and antibonding orbitals are known to control chemical reactivity. This Perspective discusses how, for reactions and kinetics of bioinorganic species, particular pathways are also exchange-enhanced — that is, favoured by an increase in the number of unpaired and spin-identical electrons on a metal centre.

When it comes to porosity, the materials that spring to mind are typically one-, two- or three-dimensional extended networks. In this Perspective, discrete organic molecules are discussed that form porous solids — either owing to hollow molecular structures or simply through inefficient packing — with different properties from those of extended networks.

The active sites of enzymes have been widely used as the inspiration for the preparation of self-assembled catalysts. This Perspective describes a more recently adopted approach to catalyst assembly that makes use of the same interactions, but takes its inspiration from more traditional organometallic and organocatalytic approaches.

Sunlight is potentially an ideal green 'reagent' for chemical synthesis, but poor absorption by organic substrates makes direct solar photochemistry generally inefficient. Here, recent progress in the use of the simple organometallic complexes to harness the power of the sun is summarized, and prospects for the future of this exciting field highlighted.