An electric molecular motor.

Macroscopic electric motors continue to have a large impact on almost every aspect of modern society. Consequently, the effort towards developing molecular motors that can be driven by electricity could not be more timely. Here we describe an electric molecular motor based on a [3]catenane, in which two cyclobis(paraquat-p-phenylene) (CBPQT) rings are powered by electricity in solution to circumrotate unidirectionally around a 50-membered loop.

Efficient electrocatalytic valorization of chlorinated organic water pollutant to ethylene.

Electrochemistry can provide an efficient and sustainable way to treat environmental waters polluted by chlorinated organic compounds. However, the electrochemical valorization of 1,2-dichloroethane (DCA) is currently challenged by the lack of a catalyst that can selectively convert DCA in aqueous solutions into ethylene. Here we report a catalyst comprising cobalt phthalocyanine molecules assembled on multiwalled carbon nanotubes that can electrochemically decompose aqueous DCA with high current and energy efficiencies.

Carbon nanotube sponges filled sandwich panels with superior high-power continuous wave laser resistance.

Effect of highly-porous and lightweight carbon nanotube sponges on the high-power continuous wave laser ablation resistance of the sandwich panel was investigated experimentally. As a comparison, thermal responses of monolithic plate, carbon nanotube film filled sandwich panel, unfilled sandwich panel and carbon nanotube sponge filled sandwich panel subjected to continuous wave laser irradiation were analyzed. Experimental results showed that the laser resistance of the carbon nanotube filled sandwich panel is obviously higher than the unfilled structure.

Phosphine Modulation for Enhanced CO Capture: Quantum Mechanics Predictions of New Materials.

It is imperative to develop efficient CO capture and activation technologies to combat the rising levels of deleterious greenhouse gases in the atmosphere. Using Quantum Mechanics methods (Density Functional Theory), we propose and evaluate several metal-free and metal-containing phosphines that provide strong CO binding under ambient conditions. Depending on the electron donating capacity of the phosphine and the ability of the P-bound ligands to hydrogen bond to the CO, we find that the CO binding can be as strong as -18.

Emulation of the structure of the Saposin protein fold by a lung surfactant peptide construct of surfactant Protein B.

The three-dimensional structure of the synthetic lung Surfactant Protein B Peptide Super Mini-B was determined using an integrative experimental approach, including mass spectrometry and isotope enhanced Fourier-transform infrared (FTIR) spectroscopy. Mass spectral analysis of the peptide, oxidized by solvent assisted region-specific disulfide formation, confirmed that the correct folding and disulfide pairing could be facilitated using two different oxidative structure-promoting solvent systems. Residue specific analysis by isotope enhanced FTIR indicated that the N-terminal and C-terminal domains have well defined α-helical amino acid sequences.

Investigations of an Unexpected [2+2] Photocycloaddition in the Synthesis of (-)-Scabrolide A from Quantum Mechanics Calculations.

We utilize ab initio quantum mechanics calculations to evaluate a range of plausible mechanistic pathways for the unexpected formation of a [6-4-4] ring system from an enone-olefin photocycloaddition in the synthesis of (-)-scabrolide A, previously reported by our group. We present a mechanistic analysis that is consistent with all current experimental observations, including the photoexcitation, the C-C bond formation, and the associated chemo- and diastereoselectivity.

Machine Learning-Aided Design of Gold Core-Shell Nanocatalysts toward Enhanced and Selective Photooxygenation.

We demonstrate the use of the machine learning (ML) tools to rapidly and accurately predict the electric field as a guide for designing core-shell Au-silica nanoparticles to enhance O sensitization and selectivity of organic synthesis. Based on the feature importance analysis, obtained from a deep neural network algorithm, we found a general and linear dependent descriptor (θ ∝ , where , , and are the shape constant, size of metal nanoparticles, and distance from the metal surface) for the electric field around the core-shell plasmonic nanoparticle. Directed by the new descriptor, we synthesized gold-silica nanoparticles and validated their plasmonic intensity using scanning transmission electron microscopy-electron energy loss spectroscopy (STEM-EELS) mapping.

Interpretable Deep Learning Model for Analyzing the Relationship between the Electronic Structure and Chemisorption Property.

The use of machine learning (ML) is exploding in materials science as a result of its high predictive performance of material properties. Tremendous trainable parameters are required to build an outperforming predictive model, which makes it impossible to retrace how the model predicts well. However, it is necessary to develop a ML model that can extract human-understandable knowledge while maintaining performance for a universal application to materials science.

Machine Learning Predicts the X-ray Photoelectron Spectroscopy of the Solid Electrolyte Interface of Lithium Metal Battery.

X-ray photoelectron spectroscopy (XPS) is a powerful surface analysis technique widely applied in characterizing the solid electrolyte interphase (SEI) of lithium metal batteries. However, experiment XPS measurements alone fail to provide atomic structures from a deeply buried SEI, leaving vital details missing. By combining hybrid and reactive molecular dynamics (HAIR) and machine learning (ML) models, we present an artificial intelligence (AI-ai) framework to predict the XPS of a SEI.

Hopping or Tunneling? Tailoring the Electron Transport Mechanisms through Hydrogen Bonding Geometry in the Boron-Doped Diamond Molecular Junctions.

Mechanisms of charge transport in molecular junctions involving hydrogen bonds are complex and remain mostly unclear. This study is focused on the elucidation of the electron transfer in a molecular device consisting of two boron-doped diamond interfaces bound with an aromatic linker and a hydrogen bonding surrogating molecule. The projected local density of states (PLODS) analysis coupled with transmission spectra and current-voltage (-) simulations show that hydrogen bonding through electron-donating hydroxyl groups in the aromatic linker facilitates electron transfer, while the electron-withdrawing carboxyl group inhibits electron transfer across the junction.

G protein coupling and activation of the metabotropic GABA heterodimer.

Metabotropic γ-aminobutyric acid receptor (GABAR), a class C G protein-coupled receptor (GPCR) heterodimer, plays a crucial role in the central nervous system. Cryo-electron microscopy studies revealed a drastic conformational change upon activation and a unique G protein (GP) binding mode. However, little is known about the mechanism for GP coupling and activation for class C GPCRs.

Selective Signal Capture from Multidimensional GPCR Outputs with Biased Agonists: Progress Towards Novel Drug Development.

G protein coupled receptors (GPCRs) are a superfamily of transmembrane-spanning receptors that are activated by multiple endogenous ligands and are the most common target for agonist or antagonist therapeutics across a broad spectrum of diseases. Initial characterization within the superfamily suggested that a receptor activated a single intracellular pathway, depending on the G protein to which it coupled. However, it has become apparent that a given receptor can activate multiple different pathways, some being therapeutically desirable, while others are neutral or promote deleterious signaling.

The mechanism for ligand activation of the GPCR-G protein complex.

G protein–coupled receptors (GPCRs) activate cellular responses ranging from odorants to neurotransmitters. Binding an agonist leads to activation of a heterotrimeric G protein (GP) that stimulates external signaling. Unfortunately, the mechanism remains unknown.

Performance of electrochemical immunoassays for clinical diagnostics of SARS-CoV-2 based on selective nucleocapsid N protein detection: Boron-doped diamond, gold and glassy carbon evaluation.

The 21st century has already brought us a plethora of new threats related to viruses that emerge in humans after zoonotic transmission or drastically change their geographic distribution or prevalence. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first spotted at the end of 2019 to rapidly spread in southwest Asia and later cause a global pandemic, which paralyzes the world since then. We have designed novel immunosensors targeting conserved protein sequences of the N protein of SARS-CoV-2 based on lab-produced and purified anti-SARS-CoV-2 nucleocapsid antibodies that are densely grafted onto various surfaces (diamond/gold/glassy carbon).

Compression Induced Deformation Twinning Evolution in Liquid-Like CuSe.

For practical applications of copper selenide (CuSe) thermoelectric (TE) materials with liquid-like behavior, it is essential to determine the structure-property relations as a function of temperature. Here, we investigate β-CuSe structure evolution during uniaxial compression over the temperature range of 400-1000 K using molecular dynamics simulations. We find that at temperatures above 800 K, CuSe exhibits poor stability with breaking order that is described as a liquid-like or hybrid structure comprising a rigid Se sublattice and mobile Cu ions.

Reaction Mechanisms, Kinetics, and Improved Catalysts for Ammonia Synthesis from Hierarchical High Throughput Catalyst Design.

The Haber-Bosch (HB) process is the primary chemical synthesis technique for industrial production of ammonia (NH) for manufacturing nitrate-based fertilizer and as a potential hydrogen carrier. The HB process alone is responsible for over 2% of all global energy usage to produce more than 160 million tons of NH annually. Iron catalysts are utilized to accelerate the reaction, but high temperatures and pressures of atmospheric nitrogen gas (N) and hydrogen gas (H) are required.

Biased β-Agonists Favoring Gs over β-Arrestin for Individualized Treatment of Obstructive Lung Disease.

Signals from G-protein-coupled receptors (GPCRs) are the most frequently targeted pathways of currently prescribed therapeutics. Rather than being a simple switch, it is now evident that a given receptor can directly initiate multiple signals, and biasing to achieve signal selectivity based on agonist structure is possible. Biased agonists could direct therapeutically favorable pathways while avoiding counterproductive or adverse reaction pathways.

Electron-catalysed molecular recognition.

Molecular recognition and supramolecular assembly cover a broad spectrum of non-covalently orchestrated phenomena between molecules. Catalysis of such processes, however, unlike that for the formation of covalent bonds, is limited to approaches that rely on sophisticated catalyst design. Here we establish a simple and versatile strategy to facilitate molecular recognition by extending electron catalysis, which is widely applied in synthetic covalent chemistry, into the realm of supramolecular non-covalent chemistry.

Identifying the Imperative Role of Metal-Olefin Interactions in Catalytic C-O Reductive Elimination from Nickel(II).

We present a series of experimental and computational mechanistic investigations of an unusually facile example of Ni-catalyzed C-O bond formation. Our method, originally reported in 2016, involves the formation of cyclic enol ethers from vinyl iodides bearing pendant alcohol groups. Our findings suggest that the observed reactivity arises from the coordination of the olefin in the vinyl iodide starting material and the enol ether product with Ni(0) intermediates.

Programmable siRNA pro-drugs that activate RNAi activity in response to specific cellular RNA biomarkers.

Since Paul Ehrlich's introduction of the "magic bullet" concept in 1908, drug developers have been seeking new ways to target drug activity to diseased cells while limiting effects on normal tissues. In recent years, it has been proposed that coupling riboswitches capable of detecting RNA biomarkers to small interfering RNAs (siRNAs) to create siRNA pro-drugs could selectively activate RNA interference (RNAi) activity in specific cells. However, this concept has not been achieved previously.

Increasing Oxygen Balance Leads to Enhanced Performance in Environmentally Acceptable High-Energy Density Materials: Predictions from First-Principles Molecular Dynamics Simulations.

Environmental concerns have stimulated the development of green alternatives to environmentally pollutive nitramine compounds used for high-energy density materials (HEDMs). The excellent energetic properties of CL20 make it a promising candidate, but its negative oxygen balance limits its efficiency for industrial and military applications. We predict here that CL20-EO formed by introducing ether links into the CC bonds of the original CL20 structure to attain balanced CO and HO production leads to improved performance while minimizing the formation of carbonaceous clusters and toxic gases.

Au-activated N motifs in non-coherent cupric porphyrin metal organic frameworks for promoting and stabilizing ethylene production.

Direct implementation of metal-organic frameworks as the catalyst for CO electroreduction has been challenging due to issues such as poor conductivity, stability, and limited > 2e products. In this study, Au nanoneedles are impregnated into a cupric porphyrin-based metal-organic framework by exploiting ligand carboxylates as the Au -reducing agent, simultaneously cleaving the ligand-node linkage. Surprisingly, despite the lack of a coherent structure, the Au-inserted framework affords a superb ethylene selectivity up to 52.

Deformation and Failure Mechanisms of Thermoelectric Type-I Clathrate BaAuGe.

Type-I clathrate BaAuGe, possessing an interesting structure stacked by polyhedrons, is a potential "phonon-glass, electron-crystal" thermoelectric material. However, the mechanical properties of BaAuGe vital for industrial applications have not been clarified. Here, we report the first density functional theory calculations of the intrinsic mechanical properties of thermoelectric clathrate BaAuGe.