Model Reaction Research Articles

Glucometabolic-Related Genes as Diagnostic Biomarkers and Therapeutic Targets for Alzheimer's Disease and Type 2 Diabetes Mellitus: A Bioinformatics Analysis.

Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM) are two widespread chronic disorders characterized by shared risk factors and molecular pathways. Glucose metabolism, pivotal for cellular homeostasis and energy supply, plays a critical role in these diseases. Its disturbance has been linked to the pathogenesis of both AD and T2DM. However, a comprehensive investigation into the specific roles of glucometabolic genes in the onset and progression of AD and T2DM has yet to be conducted. By analyzing microarray datasets from the Gene Expression Omnibus (GEO) repository, we identified differentially expressed glucometabolic genes (DEGs) in AD and T2DM cohorts. A range of bioinformatics tools were employed for functional annotation, pathway enrichment, protein interaction network construction, module analysis, ROC curve assessment, correlation matrix construction, gene set enrichment analysis, and gene-drug interaction mapping of these DEGs. Key genes were further validated using quantitative real-time polymerase chain reaction (qRT-PCR) in AD and T2DM murine models. Our investigation identified 41 glucometabolic-related DEGs, with six prominent genes (G6PD, PKM, ENO3, PFKL, PGD, and TALDO1) being common in both AD and T2DM cohorts. These genes play crucial roles in metabolic pathways including glycolysis, pentose phosphate pathway, and amino sugar metabolism. Their diagnostic potential was highlighted by area under curve (AUC) values exceeding 0.6 for AD and 0.8 for T2DM. Further analysis explored the interactions, pathway enrichments, regulatory mechanisms, and potential drug interactions of these key genes. In the AD murine model, quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed significant upregulation of G6pd, Eno3, and Taldo1. Similarly, in the T2DM murine model, elevated expression levels of G6pd, Pfkl, Eno3, and Pgd were observed. Our rigorous research sheds light on the molecular interconnections between AD and T2DM from a glucometabolic perspective, revealing new opportunities for pharmacological innovation and therapeutic approaches. This study appears to be the first to extensively investigate glucometabolic-associated DEGs and key genes in both AD and T2DM, utilizing multiple datasets. These insights are set to enhance our understanding of the complex pathophysiology underlying these widespread chronic diseases.

Comparative Study on the H-Abstraction Reactions of Isopropyl Acetate and Propyl Acetate by HO2 and OH Radicals.

Isopropyl acetate (IPA) and propyl acetate (PA) are recognized as promising biofuels suitable for applications as fuel additives and biodiesel models. The H-abstraction reactions with radicals stand out as the fundamental initiating reactions in the combustion kinetic models for IPA and PA. In the present work, the kinetic calculations of IPA and PA plus HO2 and OH radicals were investigated at M06-2X/cc-pVTZ//G4, M08-HX/maug-cc-pVTZ, and CCSD(T)/jul-cc-pVTZ levels. The thermodynamic calculations were obtained based on the G4 and CBS-APNO methods. Rate coefficients were calculated using both transition state theory and canonical variational transition state theory with tunneling correction at the temperature range of 250-2000 K. The total rate constants for the IPA + OH system were fitted as follows: k = 0.4674 × T3.927 exp(2128/T) (cm3 mol-1 s-1), and for the PA + OH system, the total rate constants were determined using the following equation: k = 0.0161 × T4.373 exp(2220/T) (cm3 mol-1 s-1). The rate coefficients of IPA + OH reactions determined based on the M08-HX/maug-cc-pVTZ level effectively replicate the experimental data, while H-abstraction rate coefficients of PA + OH by the CCSD(T)/jul-cc-pVTZ method accurately reproduce the experimental data. Refining the H-abstraction rate coefficients in the kinetic mechanism of PA, as proposed by Dayma et al. [Proc. Combust. Inst. 37 (2019) 429-436], has been achieved through incorporating the present calculated data, leading to the development of a revised mechanism. The validation of the updated mechanism against jet-stirred reactor data is presented, showcasing its effective performance in predicting JSR data.

The importance of properly correcting the electric double layer effect in unravelling the intrinsic kinetics of electrode reactions

Understanding the effects of the electric double layer (EDL) on electrode kinetics is of great importance for improving the performance of electrochemical devices. In this work, by using the HER at Au(111) in x M HClO4 ​+ ​(1−x) M NaClO4 or NaOH as a model reaction, the intrinsic kinetic parameters for HER has been unveiled based on the modified Poisson-Nernst-Planck equations and the Frumkin-Butler-Volmer theory. Our analysis reveals that i) the EDL effects induced changes in proton concentration cH+RP and electric potential ϕRP at the reaction plane are the main reason for the difference of HER current in the cases with x M HClO4 and x M HClO4 ​+ ​(1−x) M NaClO4; ii) the EDL effects are the main origin for the difference in HER current between acidic and alkaline solutions at the Au(111). Our work demonstrates that microkinetic simulation with properly considering the EDL effects is important for unravelling intrinsic reaction kinetics of electrocatalytic reactions.

Polyurethane‐based nanocomposite for catalytic reduction of toxic dyes

AbstractIn this work, we prepared AuNPs loaded polyurethane‐sodium alginate (Au‐PU‐ALg) composite polymers by casting and in‐situ reduction method. Successful fabrication of AuNPs was confirmed by UV–visible, Fourior transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), field emission scanning elcetron microscopy (FESEM), and energy dispersive X‐ray (EDX) analysis along with the change in color of the suspension from yellow to dark purple. Thermo‐gravimetric analysis (TGA) also confirmed the loading of 7.44 % AuNPs of total nanocomposite contents. The catalytic activity of Au‐PU‐ALg nanocomposites was checked by reducing Rhodamine B (RhB) as a model reaction. It was seen that reduction of RhB was successfully done in the presence of NaBH4 and Au‐PU‐ALg nanocomposite in just 8 min with value of kapp found as 0.648 min−1. While the value of kapp for RhB reduction was found as 0.0008, 0.00221, and 0.0008 min−1 in the presence of catalyst, NaBH4 and polymer gel particles, respectively. Thus results show that the value of kapp for the reduction of RhB in the presence of NaBH4 and catalyst was found high as compared to the controlled reactions. Complex mixture of dyes such as RhB, crystal violet (CV), Congo red (CR), and dyes polluted industrial wastewater was become colorless in 10 and 3 min, respectively on mixing with catalyst and reducing agent. It was also observed that reduction of RhB followed pseudo first order kinetic model and Langmuir Hinshelwood mechanism.

Quantum information scrambling and chemical reactions

The ultimate regularity of quantum mechanics creates a tension with the assumption of classical chaos used in many of our pictures of chemical reaction dynamics. Out-of-time-order correlators (OTOCs) provide a quantum analog to the Lyapunov exponents that characterize classical chaotic motion. Maldacena, Shenker, and Stanford have suggested a fundamental quantum bound for the rate of information scrambling, which resembles a limit suggested by Herzfeld for chemical reaction rates. Here, we use OTOCs to study model reactions based on a double-well reaction coordinate coupled to anharmonic oscillators or to a continuum oscillator bath. Upon cooling, as one enters the tunneling regime where the reaction rate does not strongly depend on temperature, the quantum Lyapunov exponent can approach the scrambling bound and the effective reaction rate obtained from a population correlation function can approach the Herzfeld limit on reaction rates: Tunneling increases scrambling by expanding the state space available to the system. The coupling of a dissipative continuum bath to the reaction coordinate reduces the scrambling rate obtained from the early-time OTOC, thus making the scrambling bound harder to reach, in the same way that friction is known to lower the temperature at which thermally activated barrier crossing goes over to the low-temperature activationless tunneling regime. Thus, chemical reactions entering the tunneling regime can be information scramblers as powerful as the black holes to which the quantum Lyapunov exponent bound has usually been applied.

Reductive Doping Inhibits the Formation of Isomerization‐Derived Structural Defects in N‐doped Poly(benzodifurandione) (n‐PBDF)

AbstractRecently, solution‐processable n‐doped poly(benzodifurandione) (n‐PBDF) has been made through in‐situ oxidative polymerization and reductive doping, which exhibited exceptionally high electrical conductivities and optical transparency. The discovery of n‐PBDF is considered a breakthrough in the field of organic semiconductors. In the initial report, the possibility of structural defect formation in n‐PBDF was proposed, based on the observation of structural isomerization from (E)‐2H,2′H‐[3,3′‐bibenzofuranylidene]‐2,2′‐dione (isoxindigo) to chromeno[4,3‐c]chromene‐5,11‐dione (dibenzonaphthyrone) in the dimer model reactions. In this study, we present clear evidence that structural isomerization is inhibited during polymerization. We reveal that the dimer (BFD1) and the trimer (BFD2) can be reductively doped by several mechanisms, including hydride transfer, forming charge transfer complexes (CTC) or undergoing an integer charge transfer (ICT) with reactants available during polymerization. Once the hydride transfer adducts, the CTC, or the ICT product forms, structural isomerization can be effectively prevented even at elevated temperatures. Our findings provide a mechanistic understanding of why isomerization‐derived structural defects are absent in n‐PBDF backbone. It lays a solid foundation for the future development of n‐PBDF as a benchmark polymer for organic electronics and beyond.

Reductive Doping Inhibits the Formation of Isomerization-Derived Structural Defects in N-doped Poly(benzodifurandione) (n-PBDF).

Recently, solution-processable n-doped poly(benzodifurandione) (n-PBDF) has been made through in-situ oxidative polymerization and reductive doping, which exhibited exceptionally high electrical conductivities and optical transparency. The discovery of n-PBDF is considered a breakthrough in the field of organic semiconductors. In the initial report, the possibility of structural defect formation in n-PBDF was proposed, based on the observation of structural isomerization from (E)-2H,2'H-[3,3'-bibenzofuranylidene]-2,2'-dione (isoxindigo) to chromeno[4,3-c]chromene-5,11-dione (dibenzonaphthyrone) in the dimer model reactions. In this study, we present clear evidence that structural isomerization is inhibited during polymerization. We reveal that the dimer (BFD1) and the trimer (BFD2) can be reductively doped by several mechanisms, including hydride transfer, forming charge transfer complexes (CTC) or undergoing an integer charge transfer (ICT) with reactants available during polymerization. Once the hydride transfer adducts, the CTC, or the ICT product forms, structural isomerization can be effectively prevented even at elevated temperatures. Our findings provide a mechanistic understanding of why isomerization-derived structural defects are absent in n-PBDF backbone. It lays a solid foundation for the future development of n-PBDF as a benchmark polymer for organic electronics and beyond.

Cu@SiO2 catalyst with high copper dispersion for chemoselective hydrogenation of p-chloronitrobenzene

Selective hydrogenation of p-chloronitrobenzene (p-CNB) is not only of significant industrial importance, but also an important model reaction for selectivity investigation. Despite non-precious metal Cu has been proven to be an effective promoter in bimetallic catalysts, Cu as a single active metal achieving both high conversion and high selectivity are rare reported. In this work, Cu@SiO2 catalysts with high specific surface area (509.8–694.3 m2/g), high Cu dispersion (58.4–69.6 %), and small particle size (2.0–3.0 nm) has been prepared by a simple sol–gel method. The catalysts completely suppress the dechlorination reaction, achieving complete conversion of p-CNB with 99.9 % selectivity for p-chloroaniline (p-CAN). Its microstructure, composition, chemical state, adsorption and reaction behavior have been identified by various conventional ex-situ characterizations of catalysts and in-situ DRIFTs of hydrogenation of p-CNB. Interestingly, even at high loadings, Cu in the catalyst could be highly dispersed, thus exhibiting good catalytic activity. In addition, the Cu catalyst exhibits unique adsorption performance towards p-CNB, which perhaps one of the factors for its good performance. This work not only provides a selective hydrogenation catalyst with high Cu dispersion even at high loading amount by a simple method and but also reveals the importance of the adsorption mode of p-CNB, providing guidance for the development of more efficient catalysts in the future.

Possibilities and Limitations of Kinetic Studies in On-Surface Synthesis by Real Time X-ray Photoelectron Spectroscopy.

The kinetics of coupling reactions on surfaces can be quantitatively studied in real time by X-ray Photoelectron Spectroscopy (XPS). From fitting experimental data, kinetic reaction parameters such as the rate constant's pre-exponential and activation energy can be deduced and compared to quantum chemical simulations. To elucidate the possibilities and limitations of this approach, we propose studies in which experimental data are first simulated and subsequently fitted. Knowing the exact kinetic parameters used in the simulation allows one to evaluate the accuracy of the fit result. Here, several experimental influences, such as the data point density and the addition of noise, are explored for a model reaction with first-order kinetics. The proposed procedure sheds light on the accuracy with which kinetic parameters can be derived and may also help in the design of future experiments.

A parallel line probe for spatially selective electrochemical NMR spectroscopy

In situ NMR is a valuable tool for studying electrochemical devices, including redox flow batteries and electrocatalytic reactors, capable of detecting reaction intermediates, metastable states, time evolution of processes or monitoring stability as a function of electrochemical conditions. Here we report a parallel line detector for spatially selective in situ electrochemical NMR spectroscopy. The detector consists of 17 copper wires and is doubly tuned to 1H/19F and X nuclei ranging from 63Cu (106.1 MHz) to 7Li (155.5 MHz). The flat geometry of the parallel line detector allows its insertion into a high electrode surface-to-volume electrochemical flow reactor, enabling a detector-in-a-reactor design. This integrated device is named “eReactor NMR probe”. Combined with B1-selective pulse sequences, selective detection of the nuclei at the electrode-electrolyte interface, that is within a distance of 800 μm from the electrode surface, has been achieved. The selective detection of 7Li and 19F nuclei is demonstrated using two electrolytes, LiCl and LiBF4 solutions, respectively. A good B1 homogeneity with an 810° to 90° pulse intensity ratio of 68–72 % was achieved. Using electrochemical plating of lithium metal as a model reaction, we further demonstrated the operando functionality of the probe. The new eReactor NMR probe offers a general method for studying flow electrochemistry, and we envision applications in a wide range of environmentally relevant energy systems, for example, Li metal batteries, electrochemical ammonia synthesis, carbon dioxide capture and reduction, redox flow batteries, fuel cells, water desalination, lignin oxidation etc.

Abstract 6687: Evaluation of a new co-cultured microbiome ecosystem therapy candidate (MaaT034) for clinical testing as adjuvant/neoadjuvant to immune checkpoint inhibitors in solid tumors

Abstract Background: Increasing evidence suggests that gut microbiome composition modulates tumor response to therapies, including immune checkpoint inhibitors (ICI). Clinical proofs of concept were obtained in pilot studies using healthy or ICI-responder donor-derived fecal matter transplants to modulate the gut microbiome of non-responding cancer patients and improve their response to ICI. These results support the development of Microbiome Ecosystem TherapiesTM (MET) replicating at large industrial scale the effects of ICI-responders gut microbiome. MaaT Pharma, a clinical-stage biotech, has developed a unique, ground-breaking, patented co-culture process (MET-C). MaaT034, the first-in-class co-cultured microbiome product, has been selected for optimizing intestinal homeostasis and to activate immune functions alone and in combination with an ICI treatment. Method: We combined metagenomic analysis, metabolite quantification by LC-MRM/MS, Caco-2/THP-1 leaky gut model, PBMC assay and mixed lymphocyte reaction (MLR) to assess the impact of MaaT034 on gut homeostasis and immune activation. Results: Metagenomic analysis demonstrates that MaaT034 replicates the richness and diversity of native-based microbiome ecosystems. Metabolite quantification also revealed that MaaT034 microbes secrete anti-inflammatory metabolites such as short chain fatty acids and indoles, as well as metabolites associated with ICI response such as secondary biliary acids. Using a Caco-2/THP-1 leaky gut model, we then demonstrate that MaaT034 conditioned medium was able to restore the integrity of a THP-1-induced damaged gut barrier. This was associated with and a reduction of inflammatory signals. We further performed a human PBMC assay to evaluate the impact of MaaT034 on immune cell activation. We observed the secretion of immunostimulatory cytokines associated with myeloid cell activation in response to MaaT034 conditioned medium. Notably, anti-CD3 mediated T-cells activation was further increased in response to MaaT034 conditioned medium as evidenced by increased IFNγ release associated with increased Granzyme B and CD25. Finally, MLR was performed to determine the immunomodulatory potential of MaaT034 through the interaction between T-cells and monocytes-derived dendritic cells (moDC). Interestingly, MaaT034 conditioned medium improved moDC maturation as well as moDC-induced T-cell activation. MaaT034 conditioned medium further increased anti-PD-1 mediated T-cell activation, as evidenced by IFNγ release. Conclusion: Altogether, these results highlight the potential of MaaT034 to produce metabolites involved in the restoration of gut barrier integrity and stimulation of immune cell response to ICI therapy, with potential benefit for solid tumors treatment. Citation Format: Bastien Laperrousaz, Julie Reygner, Cyrielle Gasc, Charlotte Petitjean, Aurore Duquenoy, Lora Martin, Vincent Bonnaud, Marianne Robin, Sophie Declomesnil, Carole Schwintner, Nathalie Corvaïa. Evaluation of a new co-cultured microbiome ecosystem therapy candidate (MaaT034) for clinical testing as adjuvant/neoadjuvant to immune checkpoint inhibitors in solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6687.

A method for basicity determination of thermally labile samples

BackgroundLayered double hydroxides (LDH) belong to the group of catalytic materials used in basic catalysis. Their basicity is the most important property for catalytic performance. Our work presents a possible method for the determination of such thermally labile materials' basicity using liquid phase sorption of a specific probe. ResultsAnthranilic acid was chosen as an optimal probe, and two methods were used for measuring the basic site amount – HPLC-MS and DRUV–Vis. The chosen methods described exactly the behavior of the tested LDHs in the model reaction. The basicity of LDHs increased in the row LDH2 < LDH3 < LDH2.5 which was the same trend for the conversion of reactant achieved in a model reaction. The important parameter in the model reaction and in the basicity determination was the particle size of the materials. The amount of adsorbed anthranilic acid on LDHs was in the range 197.8–199.7 mg/g, which was ten times higher than the amount adsorbed on mixed oxides (MO, the precursor for LDH preparation, adsorbed amount of anthranilic acid 13.8–18.5 mg/g). The MO adsorption of anthranilic acid showed differences in overall basicity that were not visible under conventionally used method (TPD). SignificanceThe developed method seems to be promising in the determination of the basicity of especially thermally labile materials for which the conventional methods cannot be used.

Monomethylated Tröger's-base-containing polyimidazolinium salt as an efficient catalyst for cycloaddition of CO2 to epoxides

In this work, the model reaction of benzaldehyde and ammonium chloride has been studied by detailed product analysis and characterization. Subsequently, amarine and iso-amarine hydrochlorides (1, 2), dimethylated amarine and iso-amarine ionic salts (3, 4), together with monomethylated Tröger's-base ionic salt (6) have been separately synthesized and characterized. In addition, their catalytic performance towards the cycloaddition of CO2 to epichlorohydrin is compared under identical conditions. It is observed that their catalytic activity follows the order of 3 ≈ 4 >6 > 1 ≈ 2. Inspired by the highly catalytic activity of 3, 4 and 6, a novel monomethylated Tröger's-base-containing polyimidazolinium salt (namely PMDD-IL) has been synthesized by one-pot reaction of Tröger's-base-containing dialdehyde monomer (MDD) with ammonium chloride followed by treatment with excess iodomethane in the presence of sodium hydride. The as-synthesized PMDD-IL network exhibits highly catalytic activity towards the cycloaddition of CO2 to epoxides, providing nearly quantitative selectivity (99%) and conversion (99%) over a wide substrate scope of epoxides at atmospheric CO2 pressure (epichlorohydrin, 100 °C/10 h; epibromohydrin, 100 °C/12 h; glycidyl phenyl ether, 100 °C/24 h; styrene oxide, 100 °C/24 h; and 2-butyloxirane, 100 °C/24 h). The excellent catalytic activity of PMDD-IL network can be ascribed to the high nucleophilicity of iodine anion along with the strong interactions between PMDD-IL network and CO2 molecules.

STEM-EDELCY learning model: a conceptual and pedagogical framework to facilitate students to develop 21st-century skills

ABSTRACT This research aims to describe the characteristics of the STEM-EDELCY learning model and analyze the improvement in students’ twenty-first-century skills after learning with the STEM-EDELCY model. This research involved 32 junior high school students (aged 12–13) from Indonesia. This research uses a one-group pretest-posttest design. Essay test questions and observation sheets are used to collect data on twenty-first-century skills. Data analysis of the characteristics of the STEM-EDELCY model is descriptive qualitative, while data analysis of twenty-first-century skills is a paired sample t-test. The characteristics of the STEM-EDELCY learning model can be seen in the model components, namely theory, syntax, social system, reaction principle, support system, and instructional and nurturant effects. The syntax of the STEM-EDELCY model consists of engage, defining the problem, plan and design, create, test and improve, explain, elaborate, and evaluate. Students’ twenty-first-century skills have increased significantly after participating in learning using the STEM-EDELCY model.

Asparagine-Glucose Amadori Compounds: Formation, Characterization, and Analysis in Dry Jujube Fruit.

Amadori rearrangement products of asparagine with glucose (Asn-Glc-ARP) were first prepared through Maillard model reactions and identified via liquid chromatography-mass spectroscopy. With the study on the effect of the reaction temperature, pH values, and reaction time, the ideal reaction condition for accumulation of Asn-Glc-ARP was determined at 100 °C for 40 min under pH 7. Asparagine (Asn) was prone to degrade from Asn-Glc-ARP in alkaline pH values within a lower temperature range, while in an acidic environment with high temperatures, deamidation of Asn-Glc-ARP to Asp-Glc-ARP (Amadori rearrangement products of aspartic acid with glucose) was displayed as the dominant pathway. The deamidation reaction on the side chain of the amide group took place at Asn-Glc-ARP and transferred it into the hydroxyl group, forming Asp-Glc-ARP at the end. Considering that lyophilization as pretreatment led to limited water activity, a single aspartic acid was not deamidated from Asn directly nor did it degrade from Asp-Glc-ARP even at 120 °C. The degradation of Asn-Glc-ARP through tandem mass spectrometry (MS/MS) analysis showed the obvious fragment ion at m/z 211, indicating that the stable oxonium ion formed during fragmentation. The structure of Asn-Glc-ARP was proposed as 1-deoxy-1-l-asparagino-d-fructose after separation and purification. Also, the content of Asn-Glc-ARP within dry jujube fruit (HeTianYuZao) was quantitated as high as 8.1 ± 0.5 mg/g.

Inclusion complexes of cucurbit[n]urils (n = 7, 8) with η5‐cyclopentadienyl methyl tricarbonyl molybdenum(II) and their use in epoxidation catalysis

There are very few known examples of supramolecular compounds comprising molybdenum species hosted inside the portals/cavities of cucurbit[n]urils (CBn). In this work, CB7 and CB8 macrocycles have been studied as hosts for the carbonyl complex [CpMo(CO)3Me] (1) (Cp = η5‐C5H5). Compounds were isolated in the solid state and characterized as genuine 1:1 inclusion complexes (1@CBn) by elemental and thermogravimetric analyses, powder X‐ray diffraction, scanning electron microscopy, 13C{1H} cross‐polarization magic‐angle spinning NMR, FT‐IR, Raman, and diffuse reflectance UV–Vis spectroscopies. The host–guest structures can act as supramolecular precatalysts for olefin epoxidation. Based on the model reaction of cis‐cyclooctene with hydroperoxide oxidants (tert‐butylhydroperoxide or hydrogen peroxide), the structural features of 1@CBn as well as the operating conditions influence the catalytic process. The metal species in 1@CBn undergo oxidative decarbonylation in situ, giving oxidized metal species that are catalytically active for olefin epoxidation. The type of oxidant and solvent influences the catalytic activity and stability. 1@CB8 was more stable than 1@CB7 with regard to catalyst recycling and reuse. Based on the substrate scope investigation, for relatively large olefins, such as the fatty acid methyl ester methyl oleate, the size of the macrocyclic host may be a determining factor for catalytic activity.

Biodiesel as a Sustainable Platform Chemical Enabled by Selective Partial Hydrogenation: Compounds Outplace Combustion?!

The hydrogenation of polyunsaturated fatty acids (PUFAs) in vegetable oils and their derivatives is essential for their use in many areas, such as biofuels and food chemistry. However, no attempts have been made to adapt this technology to the requirements of further chemical utilization of fatty acid methyl esters as molecular building blocks, especially for particularly promising double-bond reactions. In this work, we, therefore, use three homogeneous catalytic model reactions (hydroformylation, isomerizing methoxycarbonylation, and ethenolysis) to show, firstly, that it is already known from the literature that high PUFA contents have a negative impact on activity and selectivity. Subsequently, using the example of soybean and canola biodiesel, we demonstrate that these key figures can be drastically improved by a preceding selective partial hydrogenation. This makes it possible to first reduce the share of PUFAs to <1 w % without causing significant overhydrogenation and then to carry out hydroformylation, methoxycarbonylation, and ethenolysis with significantly increased activity (up to twentyfold) and selectivity (up to 80 % increase). With these findings, we hope to convince the scientific and industrial world of the potential of selective partial hydrogenation as a key technology for utilizing renewable raw materials and to encourage its effective use in future work.

A Computational Perspective on the Reactivity of π-spacers in Self-Immolative Elimination Reactions.

The controlled release of chemicals, especially in drug delivery, is crucial, often employing "self-immolative" spacers to enhance reliability. These spacers separate the payload from the protecting group, ensuring a more controlled release. Over the years, design rules have been proposed to improve the elimination process's reaction rate by modifying spacers with electron-donating groups or reducing their aromaticity. The spacer design is critical for determining the range of functional groups released during this process. This study explores various strategies from the literature aimed at improving release rates, focusing on the electronic nature of the spacer, its aromaticity, the electronic nature of its substituents, and the leaving groups involved in the elimination reaction. Through computational analysis, I investigate activation free energies by identifying transition states for model reactions. My calculations align qualitatively with experimental results, demonstrating the feasibility and reliability of computationally pre-screening model self-immolative eliminations. This approach allows proposing optimal combinations of spacer and leaving group for achieving the highest possible release rate.

Demagnetizing Ferromagnetic Catalysts to the Sabatier Optimal of Haber-Bosch Process.

Achieving the Sabatier optimal of a chemical reaction has been the central topic in heterogeneous catalysis for a century. However, this ultimate goal was greatly hindered in previous catalyst design strategies since the active sites indeed changed. Fortunately, the magneto-catalytic effect (MCE) provides a promising solution to this long-standing challenge. Recent research suggests that the performance of ferromagnetic catalysts is capable to be promoted without changing its chemical structure. Herein, we use time-dependent density functional perturbation theory (TDDFPT) calculations to elucidate that a partially demagnetized (DM) ferromagnet could be a Sabatier optimal catalyst. Using ammonia synthesis as the model reaction, we determined the activity of Cobalt at each DM state by including the magnetic thermal excitations via magnon analysis, making the 55% DM Co to the genuine Sabatier optimal. As an essential but underexcavated phenomenon in heterogeneous catalysis, the MCE will open a new avenue to design high-performance catalysts.

Activation volume and quantum tunneling in the hydrogen transfer reaction between methyl radical and methane: A first computational study.

We present a theory of the effect of quantum tunneling on the basic parameter that characterizes the effect of pressure on the rate constant of chemical reactions in a dense phase, the activation volume. This theory results in combining, on the one hand, the extreme pressure polarizable continuum model, a quantum chemical method to describe the effect of pressure on the reaction energy profile in a dense medium, and, on the other hand, the semiclassical version of the transition state theory, which includes the effect of quantum tunneling through a transmission coefficient. The theory has been applied to the study of the activation volume of the model reaction of hydrogen transfer between methyl radical and methane, including the primary isotope substitution of hydrogen with deuterium (H/D). The analysis of the numerical results offers, for the first time, a clear insight into the effect of quantum tunneling on the activation volume for this hydrogen transfer reaction: this effect results from the different influences that pressure has on the competing thermal and tunneling reaction mechanisms. Furthermore, the computed kinetic isotope effect (H/D) on the activation volume for this model hydrogen transfer correlates well with the experimental data for more complex hydrogen transfer reactions.