Oleg Borodin

Water‐splitting electrolyzers are a promising energy conversion technology for high‐efficiency hydrogen production. Key progress on the support and interface effects in water‐splitting electrocatalysts is highlighted. The correlation between the electronic interaction and the electrocatalytic activity of catalysts is emphatically discussed, with the aim of advancing the rapid exploration of high‐activity water‐splitting electrocatalysts.

Abstract

Water‐splitting electrolyzers that can convert electricity into storable hydrogen are a fascinating and scalable energy conversion technology for the utilization of renewable energies. To speed up the sluggish hydrogen and oxygen evolution reactions (HER and OER), electrocatalysts are essential for reducing their kinetic energy barriers and eventually improving the energy conversion efficiency. As efficient strategies for modulating the binding ability of water‐splitting intermediates on electrocatalyst surface, the support effect and interface effect are drawing growing attention. Herein, some of the recent research progress on the support and interface effects in HER, OER, and overall water‐splitting electrocatalysts is highlighted. Specifically, the correlation between the electronic interaction of the constituent components and the electrocatalytic water‐splitting performance of electrocatalysts is profoundly discussed, with the aim of advancing the development of highly efficient water‐splitting electrocatalysts, which may eventually replace the noble‐metal‐based electrocatalysts and bring the practically widespread utilization of water‐splitting electrolyzers into a reality.

Publication date: 7 March 2019

Source: Tetrahedron Letters, Volume 60, Issue 10

Author(s): Xi Shu, Ruyu Wang, Yu Fan, Shoujian Li, Chao Huang

Integrated synthesis of nucleotide and nucleosides influenced by amino acids

Integrated synthesis of nucleotide and nucleosides influenced by amino acids, Published online: 08 March 2019; doi:10.1038/s42004-019-0130-7

The direct glycosylation of ribose by nucleobases offers an intuitive route to nucleosides, but is known to be challenging under prebiotically plausible reaction conditions. Here, the addition of amino acids is shown to influence the product distribution, and a dynamic exchange of nucleobases between nucleosides and nucleotides is observed.

DNA-based communication in populations of synthetic protocells

DNA-based communication in populations of synthetic protocells, Published online: 04 March 2019; doi:10.1038/s41565-019-0399-9

Semipermeable proteinosome membranes allow complex DNA message communication through compartmentalization and protect the DNA circuits from degradation in a biological environment.

Volume 31, Issue 5, May 2019, Page 297-312
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Volume 31, Issue 5, May 2019, Page 322-335
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Braiding, branching and chiral amplification of nanofibres in supramolecular gels

Braiding, branching and chiral amplification of nanofibres in supramolecular gels, Published online: 04 March 2019; doi:10.1038/s41557-019-0222-0

Helical structures play important roles in biological processes, yet their aggregation into fibres—which can in turn form gels—is poorly understood. Now, the self-assembly of a linear pentakis (urea) peptidomimetic compound into helices that further intertwine into well-defined braided structures has been described and analysed through braid theory. Homochiral gels may be formed by exposing the precursor sol to a chiral material.

Self-assembly process of a quadruply interlocked palladium cage

Self-assembly process of a quadruply interlocked palladium cage, Published online: 01 March 2019; doi:10.1038/s42004-019-0123-6

Mechanically interlocked molecules are widely studied, but the pathways by which they assemble are less well understood. Here the formation process of a quadruply-locked Pd4L8 cage is studied by NMR and mass spectrometry, with intermediates inferred by kinetic analysis.

Huge US university cancels subscription with Elsevier

Huge US university cancels subscription with Elsevier , Published online: 28 February 2019; doi:10.1038/d41586-019-00758-x

University of California system and Dutch publisher fail to strike deal that would allow researchers to publish under open-access terms.

Halogen bonding as a supramolecular dynamics catalyst

Halogen bonding as a supramolecular dynamics catalyst, Published online: 22 February 2019; doi:10.1038/s41467-019-08878-8

The halogen bond is well known for its ability to assemble supramolecules. Here, using NMR experiments, the authors reveal the role of these bonds in dynamic processes, finding that the halogen bond directly catalyzes dynamical rotation in solid cocrystals by reducing the associated energy barrier.

Stuck like glue: Non‐enzymatic ligation of 5′‐phosphorimidazolide RNAs programmed by short splint (“guide”) RNAs allows assembly of an active RNA polymerase ribozyme from RNA oligomer fragments no longer than 30 nucleotides in a “single pot” reaction.

Abstract

Central to the “RNA world” hypothesis of the origin of life is the emergence of an RNA catalyst capable of RNA replication. However, possible replicase ribozymes are quite complex and were likely predated by simpler non‐enzymatic replication reactions. The templated polymerisation of phosphorimidazolide (Imp) activated ribonucleotides currently appears as the most tractable route to both generate and replicate short RNA oligomer pools from which a replicase could emerge. Herein we demonstrate the rapid assembly of complex ribozymes from such Imp‐activated RNA fragment pools. Specifically, we show assembly of a newly selected minimal RNA polymerase ribozyme variant (150 nt) by RNA templated ligation of 5’‐2‐methylimidazole‐activated RNA oligomers <30 nucleotides long. Our results provide support for the possibility that complex RNA structures could have emerged from pools of activated RNA oligomers and outlines a path for the transition from non‐enzymatic/chemical to enzymatic RNA replication.

3D-printed lab parts can contaminate experiments

3D-printed lab parts can contaminate experiments, Published online: 19 February 2019; doi:10.1038/d41586-019-00622-y

3D-printed lab parts can contaminate experiments

3D printing: don’t add to plastic pollution

3D printing: don’t add to plastic pollution, Published online: 19 February 2019; doi:10.1038/d41586-019-00623-x

3D printing: don’t add to plastic pollution

Atomic palladium on graphitic carbon nitride as a hydrogen evolution catalyst under visible light irradiation

Atomic palladium on graphitic carbon nitride as a hydrogen evolution catalyst under visible light irradiation, Published online: 15 February 2019; doi:10.1038/s42004-019-0117-4

Stable single-atomic and noble-metal free catalysts are crucial in light driven hydrogen evolution but their behavior upon visible light irradiation remains unclear. Here the authors develop and analyze atomic palladium on graphitic carbon nitride with enhanced catalytic activity under visible light.

How to use Twitter to further your research career

How to use Twitter to further your research career, Published online: 08 February 2019; doi:10.1038/d41586-019-00535-w

The social-media platform is often a tool for procrastination, says Jet-Sing M. Lee. But what else can it be?

The influence that the insertion method (post‐insertion vs. pre‐insertion) of “two‐wall” and “four‐wall” aryl‐extended calix[4]pyrrole carriers into liposomal membranes exerts on their chloride transport properties using the HPTS assay is described. The pre‐insertion method allowed a more accurate and reliable comparison of the transport activities of these carriers, being greater for the “four‐wall” carrier.

Abstract

We disclose the results of our investigations on the influence that the insertion method of aryl‐extended calix[4]pyrrole into liposomal membranes exerts on their properties as anion carriers. We use the standard HPTS assay to assess the transport properties of the carriers. We show that the post‐insertion of the carrier, as DMSO solution, assigns better transport activities to the “two‐wall” α,α‐aryl‐extended calix[4]pyrrole 1 compared to the “four‐wall” α,α,α,α‐counterpart 2. Notably, opposite results were obtained when the carriers were pre‐inserted into the liposomal membranes. We assign this difference to an improved incorporation of carrier 2 into the membrane when delivered by the pre‐insertion method. On the other hand, carrier 1 shows comparable levels of transport independently of the method used for its incorporation. Thus, an accurate comparison of the chloride transport activities featured by these two carriers demands their pre‐incorporation in the liposomal membranes. In contrast, using the lucigenin assay with the pre‐insertion method both carriers displayed similar transport efficiencies.

: Imine condensation that is known to the chemists for more than a century, has recently been extensively used for easy synthetic access to large organic cages of defined shapes and sizes. Surprisingly, in the context of the synthetic methodologies of organic imine cages (OICs), self‐sorting/self‐selection protocol has been overlooked over the years; while, such process omnipresent throughout nature from the creation of galaxies to the formation of smallest building unit of life (cell). Such a process has the incredible ability to guide a system towards the formation of a specific product(s) out of a collection of equally probable multiple possibilities. This review sheds light on the new opportunities in cage design offered by the self‐sorting/molecular‐ marriage protocol in organic imine cages. Herein, we also discuss the recent undergoing efforts to explore organic cages for various exciting new applications like detection of nitroaromatic explosives, as template for nucleation of very tiny metal nanoparticles (MNPs), and as a proton conducting material.

Macrocyclic molecules and spherical fullerenes: The ease of formation of “nano‐Saturns” is influenced by several factors involving size and shape fitting, and the strength of attractive interactions. Whereas typical belt‐shaped hosts include a guest via π–π interactions, disk‐shaped hosts do so via CH–π interactions and form supramolecular systems the shapes of which are close to that of the planet Saturn.

Abstract

Saturn‐like systems consisting of nanoscale rings and spheres are fascinating motifs in supramolecular chemistry. Several ring molecules are known to include spherical molecules at the center of the cavity via noncovalent attractive interactions. In this Minireview, we generalize the molecular design, the structural features, and the supramolecular chemistry of such “nano‐Saturns”, which consist of monocyclic rings and fullerene spheres (mainly C₆₀), on the basis of previous experimental and theoretical studies. Ring molecules are classified into three types (loop, belt, and disk) according to their shapes and possible interactions. Whereas typical belt‐shaped rings tend to form tight complexes due to the wide contact area via π–π interactions, flat disk‐shaped rings generally form weak complexes due to the narrow contact area mainly via CH–π interactions. In spite of the small association energies, disk‐shaped rings are attractive because such rings can mimic the planet Saturn precisely as exemplified by an anthracene cyclic hexamer–C₆₀ complex.

Host–guest complexation has been mainly investigated in solution; therefore, revealing crystal‐state host–guest complexation is a challenging task. This work reports the unique features of crystal‐state host–guest complexation; that is, how guest molecules access the host assembled structures and the dynamics of guest molecules encapsulated in crystals. More information can be found in the Full Paper by T. Ogoshi et al. on https://doi.org/10.1002/chem.201805733page 2497.

As it’s the International Year of the Periodic Table, I decided to revisit this old timeline of element discoveries I put together five years ago. The old version was a little in need of visual improvement, as well as updating to include the element discoveries confirmed since 2014.  The timeline highlights the countries in which […]

Simplest is best: Electroactive cobalt species for the oxygen evolution reaction can be prepared simply by applying an anodic bias to a mixture of a commercially available cobalt precursor and Nafion binder coated on a glassy carbon electrode. Iron dopants effectively activate the cobalt species, and most of the first row transition metals could also enhance the catalytic performance.

Abstract

In situ formation of electroactive cobalt species for the oxygen evolution reaction is simply achieved by applying an anodic bias to a commercially available cobalt precursor and Nafion binder mixture coated on a glassy carbon electrode. This preparation does not require energy‐intensive materials preparation steps or noble metals, yet a low overpotential of 322 mV at 10.2 mA cm⁻² and a high current density of more than 300 mA cm⁻² at 1.7 V_NHE were obtained in 1 m KOH. An operando electrochemical Raman spectroscopy study confirmed the formation of cobalt oxyhydroxide species and the iron stimulated the equilibrium state between Co³⁺ and Co⁴⁺. The iron present in the alkali electrolyte or ink solution effectively activated the cobalt species, and most of the first row transition metals could also enhance the catalytic performance. The concept presented here is one of the simplest strategies for preparing highly active electrocatalysts and is very flexible for the replacement of cobalt by other transition metals.

“The challenge was to introduce a dynamic open/close function in a metal‐containing cage without affecting the coordination structure.” Read more about the story behind the cover in the Cover Profile and about the research itself on page 1432 ff. (DOI: https://doi.org/10.1002/chem.20180535910.1002/chem.201805359).

Abstract

Invited for the cover of this issue is the group of Shigehisa Akine at Kanazawa University and Tatsuya Nabeshima at the University of Tsukuba. The image, designed by Prof. Akine, depicts a visualization of the possible “open” intermediate molecule that allows a guest to enter and exit. Read the full text of the article at 10.1002/chem.201805359.

The study of supramolecular structures on curved surfaces, such as, single‐walled carbon nanotubes (SWNT), is an undeveloped area in surface science. It has been confirmed that the supramolecular structures are sensitive to the chirality of SWNT beneath them. By utilizing this finding, the SWNT absolute‐handedness chirality was experimentally investigated by scanning tunneling microscopic images of supramolecular structures of porphyrin derivatives for the first time. Two opposite chiral supramolecular structures were observed based on the SWNT enantiomers handedness chirality. More information can be found in the Full Paper by A. I. A. Abd El‐Mageed, T. Ogawa et al. on https://doi.org/10.1002/chem.201804832page 1941.

“We succeeded in achieving a balance between high levels of singlet oxygen generation and high photostability, using carefully designed phthalocyanines.” Read more about the story behind the cover in the Cover Profile and about the research itself on page 1678 ff. (DOI: https://doi.org/10.1002/chem.20180508210.1002/chem.201805082).

Abstract

Invited for the cover of this issue is the group of Taniyuki Furuyama at Kanazawa University. The image depicts photostable electron‐withdrawing group substituted phthalocyanine against singlet oxygen. Read the full text of the article at 10.1002/chem.201805082.

Catalytic transport of molecular cargo using diffusive binding along a polymer track

Catalytic transport of molecular cargo using diffusive binding along a polymer track, Published online: 21 January 2019; doi:10.1038/s41557-018-0204-7

One-dimensional diffusive binding represents an important mechanism used by nature to facilitate many fundamental biochemical processes. Now, a completely synthetic system with similar capabilities has been constructed. The system was exploited to significantly speed up bimolecular reactions and to catalytically transport molecular cargo in solution and within physically separated compartments.