Volume 12 Issue 4, April 2020

Yujia Qing, an early-career researcher at the University of Oxford, talks to Nature Chemistry about winning the Dream Chemistry Award 2019, her chemistry dream of ‘Sequencing Life’, and the challenge this represents.

Luminescent metal complexes play key roles in lighting, solar energy conversion, and photocatalysis. Now, a robust zirconium complex with spectacular photophysical properties has been synthesized that could inspire the design of fundamentally new types of photoactive coordination compounds.

A heterodinuclear MgCo catalyst has been shown to be highly active for the copolymerization of CO₂ and epoxides under low (atmospheric) CO₂ pressures. Its performance arises from the intramolecular synergy between the two metals, which adopt distinct roles and mediate each other’s reactivity during catalysis.

The widespread application of quinone methides — reactive intermediates in a variety of reactions — is limited by their tedious synthesis. Now, hypoiodite catalysis allows the efficient generation and use of these species in a plethora of tandem processes for the functionalization and synthesis of biologically active compounds.

Hydrogels that can respond to multiple external stimuli are typically prepared as a single or interpenetrated polymer network material. Now, water-in-oil droplet networks have been used to precisely pattern different stimuli-responsive materials into well-ordered, continuous hydrogel structures.

The complexity of proteins has inspired chemists to seek artificial mimetics of protein structure and function. Historically, most such work has focused on analogues of small, isolated segments; however, there is growing interest in mimicry of larger, intact tertiary folds. This Perspective surveys the emerging body of work on these agents, termed ‘proteomimetics’, discusses their construction and outlines some of the remaining challenges.

A material based on a three-dimensional –Fe–N≡C–Mo– anionic framework that hosts a Cs⁺ cation in every other pore has been shown to exhibit superionic conductivity, despite its polar crystal structure. It also exhibits second harmonic generation (SHG)—usually observed in insulators—and its ionic conductivity was reversibly altered under light irradiation.

Understanding the photophysical properties of transition-metal complexes is paramount to advances in photocatalysis, solar energy conversion and light-emitting diodes. Now, long-lived emission via thermally activated delayed fluorescence has been demonstrated from an air- and water-stable zirconium complex featuring excited states with significant ligand-to-metal charge transfer character.

ortho-Quinone methides are highly reactive transient intermediates found in some organic syntheses and biological processes. The generation of these species often requires pre-functionalized substrates and/or metal oxidants, but now the chemoselective oxidative generation of ortho-quinone methides from ortho-alkylarenols has been achieved using hypoiodite catalysis under nearly neutral conditions.

Responsive hydrogels are of interest for a range of potential applications, including microscale soft robotic and biomedical devices. Now, a versatile fabrication approach has been developed to prepare patterned, multi-material and multi-responsive hydrogels. Pre-gel droplets are connected through lipid bilayers in predetermined architectures and photopolymerized to yield continuous hydrogel structures that respond to a variety of stimuli.

The copolymerization of CO₂ with epoxides is an attractive approach for valorizing waste products and improving sustainability in polymer manufacturing. Now, a heterodinuclear Mg(ii)Co(ii) complex has been shown to act as a highly active and selective catalyst for this reaction at low CO₂ pressure. The synergy between the two metals was investigated using polymerization kinetics.

A programmable polymer library that responds to external and internal stimuli has been developed and used to fabricate a series of nanocarriers for drug release. The carriers respond to disease biomarkers, triggering self-immolative motifs and leading to the site-specific release of therapeutics both in vitro and in vivo.

Generating high-energy triplet excitons from singlet fission without excess energy loss is a critical goal for potential applications. Now it is shown that molecular chromophores that are connected covalently can harbour multiple long-lived and high-energy triplets—created from one photon—only if more than two chromophoric units are present and they have sufficient flexibility to isolate the excitations upon torsional motion.

Distinguishing remote C–H bonds on adjacent carbon atoms is a fundamental challenge because of a lack of electronic or steric bias. Now, differentiation of distal C–H bonds that are adjacent to each other has been achieved by combining selective remote C–H activation—based on distance and geometry—with a norbornene-assisted palladium migration.

A method to fabricate heterotrimeric three-stranded coiled-coil peptide structures has now been developed using coordination around a Pb(ii) centre. The heterotrimeric structures require only three cysteines that bind to Pb(ii) to form a trigonal pyramidal structure, and the formation of an adjacent cavity in which water can hydrogen bond to the cysteine sulfur atoms.

The discovery of amplifying autocatalysis in a pyridine-3-carbaldehyde system facilitates a mechanistic deconstruction of the Soai reaction. A tetrameric autocatalyst, assembled by a combination of steric effects and nitrogen–zinc coordination, activates the substrate by two-point binding. This is followed by intra-complex isopropyl group transfer that generates the product alkoxide with high homochiral fidelity.