Research articles

Many drugs contain tertiary and heteroaryl amines; however, these functional groups are difficult to reversibly crosslink to a carrier protein. Now, a method for conjugating anticancer and antibiotic drugs to antibodies via a quaternary ammonium salt has been developed. Cleavage of the linker results in the traceless release of the free drug and subsequent therapeutic activity.

Achieving sequence control in a synthetic polymer is more challenging and time consuming than it is for biopolymers. Now, it has been shown that the synthesis of sequence-controlled multiblock copolymers can be carried out via emulsion polymerization. This approach is environmentally friendly and yields complex multiblock materials with low dispersity and high yields.

Reversibly inducing solid-to-liquid transitions of polymers at room temperature represents a challenge for enhanced processability and applications of polymers. Now, three azopolymers have been shown to exhibit photoswitchable glass transition temperatures, resulting in reversible solid-to-liquid transitions. Light exposure can heal cracks in hard azopolymers, reduce surface roughness of azopolymer films and control azopolymer adhesion.

A protein-only redox film inspired by the architecture of bacterial electroactive biofilms has been developed. The film is formed using a rubredoxin–prion domain chimeric protein. The prion domains self-assemble into fibres that are decorated with rubredoxin. This results in highly organized films, able to transport electrons over several microns, and wire enzymes to electrodes.

Chemical reconstitution of the triose glycolysis pathway is controlled by α-phosphorylation and provides a generational link between prebiotic ribonucleotide synthesis, triose glycolysis and serine metabolism. Now, research suggests that unification of nucleotide synthesis and triose metabolism may have been a fundamentally important step towards the origins of life.

An unanswered question in the RNA world scenario is how sequence information could be transferred during replication of duplex RNA. Without the aid of sophisticated enzymes, strand reannealing occurs more quickly than template-directed synthesis. Now, a plausible prebiotic solution to this problem is presented, in which a viscous solvent enables information transfer from a gene-length double-stranded template.

Crystals grow from nuclei. In systems where nuclei are nanometre-sized and form quickly, it is difficult to determine the mechanism of their formation. Now, through in situ TEM, the demixing of a supersaturated aqueous gold solution into metastable gold-poor and gold-rich liquid phases is observed, the latter yielding stable clusters that become nuclei for nanocrystal growth.

STM investigations and first principles calculations provide an understanding of the microscopic mechanism behind the mobility of N-heterocyclic carbenes (NHCs) on gold surfaces. Now, it is shown that a ballbot-type motion allows the formation of self-assembled monolayers due to the NHC extracting a gold atom from the surface, leading to a ligated gold adatom.

Chiral, saturated N-heterocycles are prized as pharmaceutical agents and chiral auxiliaries, but are challenging to access without using prefunctionalized starting materials. Now, chiral phosphoric acids are found to enable the enantioselective Pd(II)-catalysed arylation of α-methylene C–H bonds in a wide variety of amines using thioamide as the directing group.

The chemical construction of compartmentalized colloidal objects with biomimetic functions and collective properties is a key challenge in synthetic protocell research. Now, an interacting binary community of protocells has been designed to display artificial predatory behaviour in which protease-containing coacervate microdroplets obliterate a population of proteinosomes, and capture a chemical payload via a simple trafficking process.

A family of fluorescent molecular rotors has been developed and their mechanism for emission understood. It has been observed that, although most fluorescent molecules emit from their lowest energy excited state, S₁ (in accordance with Kasha's rule), BODIHY dyes do not. Furthermore, their fluorescence is enhanced through restricted rotor rotation, which suppresses internal conversion to the dark S₁ state.

Metal surfaces have been believed to be catalytic, but the mechanism of catalysis is unknown. Now, graphene nanoribbons (GNRs) can be grown on Au(111) from a ‘Z-bar-linkage' precursor through a conformation-controlled mechanism. Chemical vapour deposition of precursors adopting a chiral conformation produced homochiral polymers, which are dehydrogenated to form GNRs.

There is increasing evidence that highly dynamic, polydisperse peptide oligomers are the toxic species in amyloid-related diseases such as Alzheimer's and Parkinson's. Now, the secondary structure of individual amyloid oligomers has been analysed directly for the first time using a combination of ion-mobility spectrometry–mass spectrometry and gas-phase infrared spectroscopy.

Control over the selectivity of chemical reactions and biological molecules requires an intimate understanding of how conformation impacts reactivity. It is now shown that the trans conformer of trifluoromethylhydroxycarbene preferentially rearranges through a quantum-mechanical hydrogen-tunnelling pathway, whereas its cis conformer is unreactive.

During the Fischer-Tropsch catalytic reaction, alkanes are synthesized from carbon monoxide and hydrogen at high pressure and temperature. Now it is shown using scanning tunnelling imaging of a cobalt surface during reaction that linear alkane product molecules of a specific length self-assemble on terraces, facilitating the desorption of new product molecules created at step sites.

By exploiting structural rigidity, coordination geometries and bond rotational barriers that disfavour the formation of smaller homologues, molecular switches based on [c3] and [c4]daisy chains have been assembled selectively; they display muscle-like motion in multiple dimensions with changes in length of approximately 23% and 36%, respectively.

Developing approaches to tune the reactivity and selectivity of supported-metal heterogeneous catalysts is critical for designing environmentally friendly chemical conversion processes. A reversible structural catalyst transformation has now been identified that involves the adsorbate-mediated encapsulation of Rh nanoparticles by their oxide support and enables dynamic tuning of the selectivity of CO₂ reduction.

The degree to which light-induced processes are sensitive to the shape of an incident electromagnetic wave remains a hotly debated topic. Experiments performed at very low levels of light agree with seminal theoretical predictions that tuning the phase of the light field does not affect photochemical reactivity at the single-photon level.

Transition-metal-catalysed direct C(sp³)−H functionalization of primary aliphatic amines is an attractive– but elusive – process that could provide efficient access to biologically and pharmaceutically important compounds. Now, a palladium-catalysed γ-arylation of primary alkylamines is achieved using an inexpensive, catalytic and transient directing group.

Achieving high regioselectivity in hydroarylation of alkynes has been a long-standing challenge. Now, a ruthenium-catalysed decarboxylative alkyne hydroarylation with broad substrate scope, high chemo- and stereoselectivity, as well as controlled and versatile regiochemistry, is described.