The Moon-forming impact vaporized part of Earth’s mantle, and turned the rest into a magma ocean, from which carbon dioxide degassed into the atmosphere, where it stayed until water rained out to form the oceans. The rain dissolved CO2 and made it available to react with transition metal catalysts in the Earth's crust so as to ultimately generate the organic compounds that form the backbone of microbial metabolism. The Moon-forming impact was key in building a planet with the capacity to generate life in that it converted carbon on Earth into a homogeneous and accessible substrate for organic synthesis. Today all ecosystems, without exception, depend upon primary producers, organisms that fix CO2. According to theories of autotrophic origin, it has always been that way, because autotrophic theories posit that the first forms of life generated all the molecules needed to build a cell from CO2, forging a direct line of continuity between Earth's initial CO2-rich atmosphere and the first microorganisms. By modern accounts these were chemolithoautotrophic archaea and bacteria that initially colonized the crust and still inhabit that environment today.

Modified biochar was prepared directly by co-pyrolysis of MgO and rice straw in this study. The effects of single factors, such as pyrolysis temperature, dosage, pH, and coexisting ions, on phosphate adsorption performance, were investigated, and the effects of modified biochar leachate on the germination of corn and rice seeds after phosphate adsorption were examined. The results showed that phosphate adsorption by the modified biochar first increased and then decreased as the pyrolysis temperature increased, with modified biochar prepared at 800 °C showing the greatest adsorption, and the best phosphate adsorption effect of modified biochar was achieved at a dosage of 0.10 g and the solution pH=3. The adsorption kinetics study revealed that the process of phosphate adsorption by the modified biochar was more in line with the pseudo-second-order model and dominated by chemisorption, whereas the adsorption isotherm results indicated that the process of adsorption was more in line with the Langmuir model and was dominated by monomolecular layer adsorption, with a maximum adsorption of 217.54 mg/g. Subsequent seed germination tests showed that although the phosphate-adsorbed modified biochar leachate had no significant effect on the germination rate of corn seeds, it improved the germination rate of rice seeds.

Three tetraaryl-1,4-dihydropyrrolo[3,2-b]pyrrole derivatives containing different number of long alkoxy chains (2, 4 and 6) were synthesized, characterized and applied in Organic Light Emitting Diodes (OLEDs). The compounds showed good emission properties with Photoluminescence Quantum Yields (PLQYs) higher than 80% in solution and 50% in solid state (thin film). The solvatochromism results revealed a pronounced vibronic emission in methylcyclohexane and toluene, characterized by two distinct sharp emission peaks and a small redshift in the following order: methylcyclohexane > toluene > dichloromethane > tetrahydrofuran > acetonitrile. Also, the compounds formed aggregates with redshifted emission, which can be attributed to excimer formation. This phenomenon was observed in solutions containing 90% water and with the concentration variation in methylcyclohexane (MCH). Compounds with a greater number of peripheral chains showed the capacity to keep hexagonal columnar organization in films after fast cooling from liquid state. OLEDs fabricated with these compounds showed turn-on voltages lower than 4.0 V, with luminance higher than 1400 cd.m2, electroluminescence spectra with Full Width at Half Maximum lower than 70 nm and maximum External Quantum Efficiency between 7.2% and 4.3%. Overall, this shows that the 1,4-dihydropyrrolo[3,2-b]pyrrole moiety is promising for applications where luminescence is paramount, as in organic light-emitting devices

Electron paramagnetic resonance (EPR) has become a powerful probe of conformational heterogeneity and dynamics of biomolecules. In this review, we discuss different computational modeling techniques that enrich the interpretation of EPR measurements of dynamics or distance restraints. A variety of spin labels are surveyed to provide a background for the discussion of modeling tools. Molecular dynamics (MD) simulations of models containing spin labels provide dynamical properties of biomolecules and their labels. These simulations can be used to predict EPR spectra, sample stable conformations and sample rotameric preferences of label sidechains. For molecular motions longer than milliseconds, enhanced sampling strategies and de novo prediction software incorporating or validated by EPR measurements are able to efficiently refine or predict protein conformations, respectively. To sample large-amplitude conformational transition, a coarse-grained or an atomistic weighted ensemble (WE) strategy can be guided with EPR insights. Looking forward, we anticipate an integrative strategy for efficient sampling of alternate conformations by de novo predictions, followed by validations by systematic EPR measurements and MD simulations. Continuous pathways between alternate states can be further sampled by WE-MD including all intermediate states.

An oral gastrointestinal-based anticancer nanocarrier (Am7CD/SDS NPs) was equipped with both pH and temperature sensitivity, which could effectively prevent MTX@Am7CD/SDS NPs from being degraded in the acidic environment mimicking the stomach and small intestine, thus harboring the potential to accumulate at the site of colon lesions and further release drugs under mild conditions.

Abstract

Colon cancer is emerging as one of the most common cancers worldwide, ranking in the top three in morbidity and mortality. Oral methotrexate (MTX) has been employed as a first-line treatment for various cancers, such as colon, breast, and lung cancer. However, the complexity and particularity of the gastrointestinal microenvironment and the limitations of MTX itself, including severe adverse effects and instability, are the main obstacles to the safe delivery of MTX to colon tumor sites. Herein, an innovative oral administrated anticancer therapeutic MTX@Am7CD/SDS NPs equipped with both pH and temperature sensitivity, which could effectively prevent MTX@Am7CD/SDS NPs from being degraded in the acidic environment mimicking the stomach and small intestine, thus harboring the potential to accumulate at the site of colon lesions and further release intestinal drug under mild conditions. In cellular assays, compared with free MTX, MTX@Am7CD/SDS NPs showed a favorable tumor inhibition effect on three tumor cell lines, as well as excellent cell uptake and apoptosis-inducing effect on SW480 cells. Therefore, this work provides a feasible solution for the safe use of MTX in the treatment of colon cancer and even other intestinal diseases.

5-hydroxymethylfurfural represents a key chemical in the drive towards a sustainable circular economy within the chemical industry. The final step in 5-hydroxymethylfurfural production is the acid catalysed dehydration of fructose, for which supported organoacids are excellent potential catalyst candidates. Here we report a range of solid acid catalysis based on sulphonic acid grafted onto different porous silica nanosphere architectures, as confirmed by TEM, N2 porosimetry, XPS and ATR-IR. All four catalysts display enhanced active site normalised activity and productivity, relative to alternative silica supported equivalent systems in the literature, with in-pore diffusion of both substrate and product key to both performance and humin formation pathway. An increase in-pore diffusion coefficient of 5-hydroxymethylfurfural within wormlike and stellate structures results in optimal productivity. In contrast, poor diffusion within a raspberry-like morphology decreases rates of 5-hydroxymethylfurfural production and increases its consumption within humin formation.

Catalytic amounts of phosphines, such as P ⁿ Bu₃ and PCy₃, have a positive effect on the activity of cobalt phosphide nano-urchins for the semi-hydrogenation of phenylacetylene at 100 °C under H₂ (7 bars).

Abstract

Transition metal phosphides are promising, selective, and air-stable nanocatalysts for hydrogenation reactions. However, they often require fairly high temperatures and H₂ pressures to provide quantitative conversions. This work reports the positive effect of phosphine additives on the activity of cobalt phosphide nano-urchins for the semi-hydrogenation of phenylacetylene. While the nanocatalyst's activity was low under mild conditions (7 bar of H₂, 100 °C), the addition of a catalytic amount of phosphine remarkably increased the conversion, e. g., from 13 % to 98 % in the case of P ⁿ Bu₃. The heterogeneous nature of the catalyst was confirmed by negative supernatant activity tests. The catalyst integrity was carefully verified by post-mortem analyses (TEM, XPS, and liquid ³¹P NMR). A stereo-electronic map was proposed to rationalize the activity enhancement provided over a selection of nine phosphines: the strongest effect was observed for low to moderately hindered phosphines, associated with strong electron donor abilities. A threshold in phosphine stoichiometry was revealed for the enhancement of activity to occur, which was related to the ratio of phosphine to surface cobalt atoms.

Development of a comprehensive protocol for the production of Certified Reference Materials (CRM) of amphetamine and related compounds from a simple, rapid, and efficient synthesis under batch and continuous-flow conditions are reported in this work, accompanied by the establishment of a certification procedure for these materials through identity checking, homogeneity, stability, and characterization studies.

Abstract

Certified reference materials (CRM) of amphetamine derivatives were produced through a simple, rapid and efficient synthesis in both batch and continuous-flow conditions, accompanied by the development of a comprehensive certification protocol for this class of substances. Our chemistry enabled the synthesis of MDA, MDMA, PMA and PMMA in two steps from safrole and estragole with overall yields of 38–61 % in 48 hours under batch conditions and 61–65 % in 65 minutes under continuous-flow conditions, followed by the development of a certification protocol for these materials through identity checking, homogeneity, stability, and characterization studies. Furthermore, as result of this work, a very pure CRM of MDA.HCl with 99.1±1.4 g/100 g of certified characterization value was produced. Considering the importance of supplying amphetamine calibrants for public security efforts in Forensic Chemistry, the potential therapeutical applications, and responding to the rising demand for the synthesis of CRM, this work presents a pioneering approach for the production of amphetamine and related compounds.

Supramolecular Organic Frameworks (SOFs) are an emerging class of porous materials based on the self-assembly of organic tectons through non-covalent interactions. For their flexibility, SOFs can show dynamic behaviour undergoing reversible transformations triggered by external physical and/or chemical stimuli, particularly when exposed to guest adsorption in the liquid or gas phase.

Abstract

Supramolecular organic frameworks (SOFs) are a class of three-dimensional, potentially porous materials obtained by the self-assembly of organic building blocks held together by weak interactions such as hydrogen bonds, halogen bonds, π⋅⋅⋅π stacking and dispersion forces. SOFs are being extensively studied for their potential applications in gas storage and separation, catalysis, guest encapsulation and sensing. The supramolecular forces that guide their self-assembly endow them with an attractive combination of crystallinity and flexibility, providing intelligent dynamic materials that can respond to external stimuli in a reversible way. The present review article will focus on SOFs showing dynamic behaviour when exposed to different stimuli, highlighting fundamental aspects such as the combination of tectons and supramolecular interactions involved in the framework formation, structure-property relationship and their potential applications.

This article is a detailed review of ADCs in the field of electrocatalysis: the economic production, electrocatalytic reaction pathways and associated mechanisms, uncovered structure-performance relationships, the major challenges and opportunities in this field. This review provides a systematic summary in the light of the differences in their electrocatalytic performances for a certain reaction due to the differences in preparation strategies, active site design, etc.

Abstract

Distinguishing themselves from nanostructured catalysts, single-atom catalysts (SACs) typically consist of positively charged single metal and coordination atoms without any metal-metal bonds. Dual-atom catalysts (DACs) have emerged as extended family members of SACs in recent years. Both SACs and DACs possess characteristics that combine both homogeneous and heterogeneous catalysis, offering advantages such as uniform active sites and adjustable interactions with ligands, while also inheriting the high stability and recyclability associated with heterogeneous catalyst systems. They offer numerous advantages and are extensively utilized in the field of electrocatalysis, so they have emerged as one of the most prominent material research platforms in the direction of electrocatalysis. This review provides a comprehensive review of SACs and DACs in the field of electrocatalysis: encompassing economic production, elucidating electrocatalytic reaction pathways and associated mechanisms, uncovering structure-performance relationships, and addressing major challenges and opportunities within this domain. Our objective is to present novel ideas for developing advanced synthesis strategies, precisely controlling the microstructure of catalytic active sites, establishing accurate structure-activity relationships, unraveling potential mechanisms underlying electrocatalytic reactions, identifying more efficient reaction paths, and enhancing overall performance in electrocatalytic reactions.