News & Views in 2014

The synthesis of [5]CPP, the smallest and by far the most strained member of the family of macrocycles known as cycloparaphenylenes, has been reported in quick succession by two different research groups. But how long will the new record holder retain its title?

Biological solar energy conversion requires the coordinated and rapid movement of protons and electrons through complex proteins, called reaction centres. Now, an artificial and structurally simple reaction centre has been synthesized that mimics an important, photosynthetic charge relay.

Force-induced covalent bond changes in mechanophore-linked polymers typically require large, irreversible material deformation, limiting successive activation cycles. Now, repeated force-induced reactions have been achieved by incorporating flex-activated mechanophores into elastomeric networks.

Nanoscopic templates functionalized with light-reactive chromophores could ultimately be used to store solar energy and later release it as heat. Now, it has been shown that packing the chromophores together increases both storage capacity and lifetime.

Labelling of proteins with pairs of fluorophores enables their conformations to be studied; however, complete incorporation of labels in multiple, pre-defined locations is very difficult. Now, a combination of double unnatural amino acid mutagenesis and selective chemical modification offers a general method to achieve this.

Kinetic isotope effects are widely used to elucidate reaction mechanisms and are generally interpreted in terms of simple kinetic models. Measurements of this effect for the Penning ionization reaction between helium and dihydrogen highlight the need for a quantum description of chemical reaction rates when sub-kelvin temperatures are approached.

A combination of catalytic asymmetric diboration of terminal alkenes and Suzuki–Miyaura cross-coupling has been exploited in the synthesis of a variety of important medicinal agents. The process overcomes a number of problems in the application of these important catalytic processes.

The development of methods for efficiently using carbon dioxide in synthesis would enable chemists to tap into this abundant resource. Now, an indirect route to the copolymerization of alkenes with carbon dioxide shows how this greenhouse gas may prove useful in the search for new 'green' materials.

Amyloid fibrils are formed from polypeptide chains assembled into an organized fibrillar structure. Now, it has been shown that such fibrillar structures can also bind metal ions and catalyse chemical reactions.

Separating carbon monoxide from chemically similar nitrogen gas is particularly challenging. Now, a flexible porous coordination polymer has been developed that recognizes carbon monoxide over nitrogen, with structural changes in the material leading to its accelerated adsorption.

Pigment assemblies with high-efficiency electronic energy transfer have recently been observed to show unusual and persistent coherence, but its origin is not fully understood. Now, a combination of 2D electronic spectroscopy and theoretical modelling has allowed the excitonic coherence signal of a strongly coupled homodimer to be isolated.

ATP synthase is an important enzyme for the storage and release of energy in cells. Ion-mobility mass spectrometry has now been used to study its structure, revealing important mechanistic details about its operation and regulation.

Enzymes catalyse nearly all of the myriad chemical reactions that occur in every living organism. An easily understandable, visually appealing model has now been described that illustrates the fundamentals of how enzymes work.

The amount of uranium in seawater vastly exceeds that in land-based deposits; but separating it from other more abundant metal ions requires high affinity, selectivity — and the ability to deal with an enormous volume of water. Now, two complementary approaches have made considerable contributions to overcoming these challenges.

Protein fibril formation is involved in many human diseases and thus has been mechanistically elucidated in the context of understanding — and in turn treating — them. This biological phenomenon has now also inspired the design of a supramolecular system that undergoes living polymerization.

Cytochrome P450 enzymes are able to oxidize substrates that are more inert than their own surrounding protein framework. Now, a quantitative understanding has emerged as to how the enzymes accomplish this remarkable feat.

High selectivity is essential in the enzymatic biosynthesis of complex natural products. Now, the discovery of multiple sequential bifurcations on the reaction path towards the formation of a diterpenoid shows how dynamics affect selectivity, and suggests how enzymes may steer reactions towards a specific product.

Discovering and validating new targets is urgently required to tackle the rise in resistance to antimalarial drugs. Now, inhibition of the enzyme N-myristoyltransferase has been shown to prevent the formation of a critical subcellular organelle in the parasite that causes malaria, leading to death of the parasite.

The organic synthesis of graphene nanostructures requires exceptionally efficient chemistry and is made more challenging by difficulties in characterization and processing. Now, solution-dispersible graphene nanoribbons have been synthesized on the gram scale.

Metal-coordinating groups are widely used to direct C–H functionalization. Now the combination of an alkene hydrosilylation, C–H activation and C–Si oxidation has been used to achieve a formal 1,4-dioxygenation of alkenes.