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Agnieszka Karczmarczyk,1 Maciej Korpysz,2 Sylwia Bilska,3 Joanna Purkot,1 Marek Hus,3 Krzysztof Giannopoulos1,4 1Department of Experimental Hematooncology, Medical University of Lublin, Lublin, Poland; 2Department of Biochemical Diagnostics, Medical University of Lublin, Lublin, Poland; 3Department of Hematooncology and Bone Marrow Transplantation, Medical University of Lublin, Lublin, Poland; 4Department of Hematology, St. John’s Cancer Centre, Lublin, PolandCorrespondence: Krzysztof Giannopoulos, Department of Experimental Hematooncology, Medical University of Lublin, Chodzki 1, Lublin, 20-093, Poland, Tel + 48 81448 6632, Fax + 48 81448 6634, Email krzysztof.giannopoulos@gmail.comPurpose: Among hematological malignancies, the expression profile of programmed cell death-1 (PD-1) and its ligands in multiple myeloma (MM) is still debated by numerous research groups. In current study, we characterized the expression of PD-1 and its ligands both on RNA and protein levels in MM patients. We have also attempted to analyze whether daratumumab therapy might overcome CD38-mediated immunosuppression that inhibits in particular CD8+ T-cell function.Patients and Methods: This study included 149 newly diagnosed MM patients and 15 relapsed/refractory MM patients before and after daratumumab treatment. The mRNA levels of PDCD1, PDCD1LG1, PDCD1LG2 and their splicing variants was assessed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Flow cytometry was used to characterize the surface expression of PD-1 and its ligands on plasma cells, B and T cells. The surface expression of PD-1 on T cells was assessed by flow cytometry before and after daratumumab treatment.Results: The mRNA expression of PDCD1LG1, PDCD1LG2 and their splicing variants were higher in plasma cells as compared to bone marrow mononuclear cells (BMMCs). Our results show that the percentage of plasma cells expressing PD-L1 was significantly higher than plasma cells expressing PD-L2 (p< 0.0001) in bone marrow (BM) of MM patients. There was no significant difference between the percentage of plasma cells expressing PD-1 and B cells expressing PD-1 in BM of MM patients (11.19% vs 8.91%). We also found that the percentage of CD8+PD-1+ T cells was significantly higher than CD4+PD-1+T cells in BM (p< 0.0001) of MM patients. Here, we observed no change in PD-1 expression on CD4+ and CD8+ T cells after the daratumumab treatment.Conclusion: The PD-1 and its ligands might represent an interesting target for MM immunotherapy, as one would target both malignant plasma cells as well as the immune cells that play a key role in tumor escape mechanisms.Keywords: PD-1, PD-L1, PD-L2, daratumumab, multiple myeloma

Marta Masternak,1 Bartosz Puła,2 Joanna Knap,1 Anna Waszczuk-Gajda,3 Joanna Drozd-Sokołowska,3 Kamil Wdowiak,4 Sebastian Grosicki,5 Izabela Kozłowska,6 Marta Kaźmierczak,6 Anna Łabędź,7 Łukasz Szukalski,8 Kamil Wiśniewski,2 Edyta Subocz,9 Janusz Hałka,10 Agnieszka Szymczyk,11 Marek Hus,12 Krzysztof Jamroziak,2 Krzysztof Giannopoulos13 1Department of Experimental Hematooncology, Medical University of Lublin, Lublin, Poland; 2Department of Hematology, Institute of Hematology and Transfusion Medicine, Warsaw, Poland; 3Department of Hematology, Oncology and Internal Diseases, Medical University of Warsaw, Warsaw, Poland; 4Department of Internal Medicine and Oncological Chemotherapy, Silesian Medical University, Katowice, Poland; 5Department of Hematology and Cancer Prevention in Chorzow, Faculty of Health Sciences in Bytom, Silesian Medical University, Katowice, Poland; 6Department of Hematology and Cancer Prevention, Municipal Hospital in Chorzów, Chorzów, Poland; 7Department of Hematology, Rydrygier’s Hospital in Cracow, Cracow, Poland; 8Department of Hematology, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Toruń, Poland; 9Department of Hematology, Military Institute of Medicine, Warsaw, Poland; Clinical Department of Hematology, Independent Public Healthcare Centre of the Ministry of Internal Affairs and Administration with Warmia-Mazury Region’s Oncology Centre in Olsztyn, Olsztyn, Poland; 10Clinical Department of Hematology, Independent Public Healthcare Centre of the Ministry of Internal Affairs and Administration with Warmia-Mazury Region’s Oncology Centre in Olsztyn, Olsztyn, Poland; 11Department of Hematooncology and Bone Marrow Transplantation, Medical University of Lublin, Lublin, Poland; Hematology Department, St John’s Cancer Center, Lublin, Poland; 12Department of Hematooncology and Bone Marrow Transplantation, Medical University of Lublin, Lublin, Poland; 13Department of Experimental Hematooncology, Medical University of Lublin, Lublin, Poland; Hematology Department, St John’s Cancer Center, Lublin, PolandCorrespondence: Krzysztof Giannopoulos Tel +48 81448 6632Fax +48 81448 6634Email krzysztof.giannopoulos@gmail.comPurpose: Mean platelet volume (MPV) is a readily accessible and commonly tested hematological indicator. Recent studies revealed a significant impact of MPV on the course and prognosis of many diseases, including some types of cancer, as well as on the incidence of atrial fibrillation and bleeding. The study aimed to perform a retrospective analysis of MPV in terms of time to first treatment (TTFT) and to determine its prognostic value in the group of patients with chronic lymphocytic leukemia (CLL). Moreover, the study includes a retrospective analysis of platelet parameters in patients treated with ibrutinib concerning bleeding and atrial fibrillation.Patients and Methods: The study included 523 patients with CLL, for 344 the most important cytogenetic aberrations were reported. The Mann–Whitney, Kruskal–Wallis, Kaplan–Meier, chi-squared, log‑rank tests and multivariate Cox proportional hazard regression model were used to analyze collected data.Results: The receiver operating characteristic curve analysis was performed to identify optimal cut-off value for MPV. The analysis of survival curves showed that in the group of patients with higher values of MPV TTFT was significantly longer than in the group with lower MPV (17.9 vs 36 months, p=0.0015, cut-off value for MPV= 10.4 fl). In multivariate Cox proportional hazard regression model low MPV, the presence of del11q and del13q provided independent prognostic value for TTFT (HR=0.69, 95%-CI, 0.5293 to 0.9081; p=0.0078; HR=1.76, 95%-CI, 1.3000 to 2.3882, p=0.0003, HR=0.74, 95%-Cl, 0.5674 to 0.9588, p=0.0229, respectively). In the group treated with ibrutinib, 59 patients had no significant correlation between MPV level and the incidence of therapy complications, although in the group of patients with low MPV there was a tendency for more frequent occurrence of atrial fibrillation (p=0.259).Conclusion: Low MPV values are associated with unfavorable prognosis and might represent a novel, independent prognostic factor in CLL.Keywords: MPV, chronic lymphocytic leukemia, TTFT

Agnieszka Szymczyk,1,2 Sylwia Chocholska,1 Arkadiusz Macheta,1 Dariusz Szczepanek,3 Marek Hus,1 Monika Podhorecka11Department of Haematooncology and Bone Marrow Transplantation, Medical University of Lublin, Lublin, Poland; 2Department of Clinical Transplantology, Medical University of Lublin, Lublin, Poland; 3Department of Neurosurgery and Pediatric Neurosurgery, Medical University of Lublin, Lublin, PolandBackground: Great progress has been achieved lately in the therapy for chronic lymphocytic leukemia (CLL), one of the most frequently diagnosed adult leukemias. New classes of drugs, such as kinase inhibitors and BCL-2 protein antagonists, have been approved for treatment of CLL patients. Despite the abovementioned therapies the disease can still be effectively treated with purine nucleoside analogs (PNA). However, some patients, for example, those with TP53 gene abnormalities, become resistant, and the other factors involved in the therapy resistance are still being investigated. This study was aimed at analyzing the possible role of microRNAs as markers predicting the outcome of chemotherapy based on PNA – fludarabine and cladribine in CLL patients.Methods: The expression of miR-21, miR-34a, miR-181a and miR-221 in previously separated leukemic cells was assessed with the use of qRQ-PCR technique at the moment of diagnosis in 40 CLL patients. In turn, apoptosis induced by fludarabine and cladribine in 24-hour cell culture was evaluated by determining the increase in the percentage of apoptotic cells of CD5+/CD19+/Cas3+ phenotype, using a flow cytometry method. Nine of the 40 studied subjects were treated with fludarabine-based regimens and were analyzed with regards to in vivo response to PNA.Results: We detected a significantly higher PNA-induced apoptosis rate in patients with high miR-34a expression in comparison to low expression ones. Interestingly, such differences were detected particularly in standard cytogenetic patients.Conclusions: These results may prove an important role of miR-34a expression as a predictor of apoptosis, even in cases when other risk factors like cytogenetic abnormalities are absent. An assessment of microRNAs expression seems to be useful as an indicator of sensitivity to PNA and may help to predict PNA-based therapy outcome.Keywords: chronic lymphocytic leukemia, microRNA, purine nucleoside analog, prognostic markers, apoptosis

Efficient CO2 capture at concentrations between 400-2000 ppm is essential for maintaining air quality in a habitable environment and advancing carbon capture technologies. This study introduces NICS-24 (National Institute of Chemistry Structures No. 24), a Zn-oxalate 3,5-diamino-1,2,4-triazolate framework with two distinct square-shaped channels, designed to enhance CO2 capture at indoor-relevant concentrations. NICS-24 exhibits a CO2 uptake of 0.7 mmol/g at 2 mbar and 25 °C, significantly outperforming the compositionally related Zn-oxalate 1,2,4-triazolate - CALF-20 (0.17 mmol/g). Improved performance is attributed to amino-functions that enhance CO2 binding and enable superior selectivity over N2 and O2, achieving 8-fold and 30-fold improvements, respectively, in simulated CO2/N2 and CO2/O2 atmospheric ratios. In humid environments, NICS-24 retained structural integrity but exhibited an 85 % reduction in CO2 capacity due to competitive water adsorption. Breakthrough sorption experiments, atomistic NMR analysis, and DFT calculations revealed that water preferentially adsorbs over CO2 due to strong hydrogen-bonding interactions within the framework. Gained understanding of the interaction between CO2 and H2O within the MOF framework could guide the modification via rational design with improved performance under real-world conditions., (© 2025 Wiley‐VCH GmbH.)

Iminophosphoranes with the general formula (R 3 P═NR') have great potential in synthetic chemistry as valuable precursors/intermediates in organic synthesis or as building blocks for various organic compounds. However, the synthetic approaches and conditions to prepare iminophosphoranes are still poorly understood, limiting the utility of this chemistry for organic materials. In this article, a simple and efficient synthesis of previously unattainable poly(arylene iminophosphoranes) is reported. The azide-phosphine Staudinger polycondensation is used, and the reaction conditions are carefully studied, including consideration of light and air, the influence of solvent and temperature, and investigation of the electronic and steric effects of multiazides. The newly defined reaction conditions appear to be highly versatile, allowing the use of both electron-rich and electron-deficient arylazides for reaction with phosphines to synthesize a library of poly(arylene iminophosphorane) networks that exhibit exceptional thermal and oxidative stability. Interestingly, despite the ylidic-form of the iminophosphorane linkage as shown by theoretical calculations, these newly developed poly(arylene-iminophosphorane) networks exhibit semiconducting properties, such as absorption band edges up to 800 nm and optical band gaps in the range of 1.70 to 2.40 eV. Finally, we demonstrate the broad applicability of these polymers by processing them into glassy films, creating foam-like structures and synthesizing metallo-polymer hybrids., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Although CO 2 contributes significantly to global warming, it also offers potential as a raw material for the production of hydrocarbons such as CH 4 , C 2 H 4 and CH 3 OH. Electrochemical CO 2 reduction reaction (eCO 2 RR) is an emerging technology that utilizes renewable energy to convert CO 2 into valuable fuels, solving environmental and energy problems simultaneously. Insights gained at any individual scale can only provide a limited view of that specific scale. Multiscale modeling, which involves coupling atomistic-level insights (density functional theory, DFT) and (Molecular Dynamics, MD), with mesoscale (kinetic Monte Carlo, KMC, and microkinetics, MK) and macroscale (computational fluid dynamics, CFD) simulations, has received significant attention recently. While multiscale modeling of eCO 2 RR on electrocatalysts across all scales is limited due to its complexity, this review offers an overview of recent works on single scales and the coupling of two and three scales, such as "DFT+MD", "DFT+KMC", "DFT+MK", "KMC/MK+CFD" and "DFT+MK/KMC+CFD", focusing particularly on Cu-based electrocatalysts as copper is known to be an excellent electrocatalyst for eCO 2 RR. This sets it apart from other reviews that solely focus exclusively on a single scale or only on a combination of DFT and MK/KMC scales. Furthermore, this review offers a concise overview of machine learning (ML) applications for eCO 2 RR, an emerging approach that has not yet been reviewed. Finally, this review highlights the key challenges, research gaps and perspectives of multiscale modeling for eCO 2 RR., (© 2024 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

The reverse water gas shift (RWGS) reaction converts CO 2 and H 2 into CO and water. We investigated Cu/γ-Al 2 O 3 catalysts in both thermally driven and light-assisted RWGS reactions using visible light. When driven by combined visible light and thermal energy, the CO 2 conversion rates were lower than in the dark. Light-assisted reactions showed an increase in the apparent activation energy from 68 to 87 kJ/mol, indicating that light disrupts the energetically favorable pathway active in the dark. A linear correlation between irradiance and decreasing reaction rate suggests a photon-driven phenomenon. In situ diffuse reflectance infrared Fourier transform spectroscopy and TD-DFT analyses revealed that catalyst illumination causes significant, partly irreversible surface dehydroxylation, highlighting the importance of OH groups in the most favorable RWGS pathway. This study offers a novel approach to manipulate surface species and control activity in the RWGS reaction.

Storing and transporting pressurized or liquid hydrogen is expensive and hazardous. As a result, safer methods, such as chemical storage in ammonia, are becoming increasingly important. However, the instantaneous start of a conventionally heated decomposition reactor is challenging. Here we report on the electrified and dynamically responsive decomposition of ammonia as a means of releasing on-demand chemically bonded hydrogen based on the rapid magnetic heating of a well-designed Ru-based nanocomposite catalyst. Under relatively mild conditions (400 °C, 1 bar) a rapid decomposition rate of 5.33 mol NH3  g Ru -1  h -1 was achieved. Experimental observations under non-isothermal, dynamic conditions coupled with modelling at the level of density functional theory and micro-kinetic modeling confirmed the minute-scale response of the H 2 release. The rapid response of our catalytic system would, at least in principle, enable the utilization of intermittent, renewable electricity and a tunable H 2 /NH 3 ratio in the reactor's effluent., (© 2024 The Author(s). ChemSusChem published by Wiley-VCH GmbH.)

Cellulose nanofibrils are one of the keystone materials for sustainable future, yet their poor water repellency hinders their push into industrial applications. Due to complexity and poor economical outcome and/or processing toxicity of the existing hydrophobization methods, nanocellulose loses against its antagonist plastic in medical and food industries. Herein, we demonstrate for the first time the "one-side selective water-repellency activation" in nanocellulose membranes by the means of mild N 2 -plasma treatment, exhibiting lowest wettability after 20 s of treatment. Hydrophobicity and accompanying Janus character were justified by the topological, chemical and structural reorganizations in cellulose nanofibrils. The findings suggest that the mechanism behind the hydrophilic/hydrophobic change primarily relies on the interplay between OH removal and appearance of SiCH 3 , originating from the polysiloxanes-based substrate, as well as complementary CNH 2 groups formation. First-principles calculations show that NH 2 groups moderately increase hydrophobicity, while various SiCH 3 substitutions wholly change the character of the surface to repel water. Using nitrogen is shown to be crucial, as N(H)Si(CH 3 ) 3 groups induce greater hydrophobicity than simple OSi(CH 3 ) 3 . Finally, the obtained materials absorb water on the hydrophilic side, while remaining hydrophobic on the other, exhibit high tensile strength, and protection against UV light, demonstrating applicability over wide range of applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Electrochemical reduction reaction of CO 2 (eCO 2 RR) to produce valuable chemicals offers an attractive strategy to solve energy and environmental problems simultaneously. We have mapped out entire reaction pathways of eCO 2 RR to CO on Cu(100), including all intermediates and transition states using first-principles simulations. To accurately account for the solvent effect, the reaction was investigated with and without explicit water molecules, highlighting the limitations of the often (mis)used vacuum reaction pathway simplification. The results show that the reduction reaction was initiated under neutral pH conditions at an applied potential of -0.11 V (RHE, reversible hydrogen electrode) and all elementary reactions were thermodynamically favorable, while an applied potential of -1.24 V is required to ensure that all reactions exhibit spontaneous behavior. Detailed analysis revealed that solvation significantly influences the stability of the adsorbates and intermediates. Its inclusion notably alters the calculated reaction kinetics and energetic parameters by lowering the barrier energies and Gibbs free energies of all reactions. CO production proceeded mainly via the COOH* pathway (CO 2 →trans-COOH*→cis-COOH*→CO*+OH*→CO*→CO). The use of water as a more sustainable and cost-effective solvent is compared to other options such as organic solvents, ionic liquids and mixed solvent systems, which are less sustainable and more expensive., (© 2024 The Author(s). ChemPlusChem published by Wiley-VCH GmbH.)

The process of N-doping is frequently employed to enhance the properties of carbon quantum dots. However, the precise requirements for nitrogen precursors in producing high-quality N-doped carbon quantum dots (NCQDs) remain undefined. This research systematically examines the influence of various nitrogen dopants on the morphology, optical features, and band structure of NCQDs. The dots are synthesized using an efficient, eco- friendly, and rapid continuous hydrothermal flow technique. This method offers unparalleled control over synthesis and doping, while also eliminating convention-related issues. Citric acid is used as the carbon source, and urea, trizma base, beta-alanine, L-arginine, and EDTA are used as nitrogen sources. Notably, urea and trizma produced NCQDs with excitation-independent fluorescence, high quantum yields (up to 40%), and uniform dots with narrow particle size distributions. Density functional theory (DFT) and time-dependent DFT modelling established that defects and substituents within the graphitic structure have a more significant impact on the NCQDs' electronic structure than nitrogen-containing functional groups. Importantly, for the first time, this work demonstrates that the conventional approach of modelling single-layer structures is insufficient, but two layers suffice for replicating experimental data. This study, therefore, provides essential guidance on the selection of nitrogen precursors for NCQD customization for diverse applications., (© 2024 The Authors. Small published by Wiley‐VCH GmbH.)

The article discusses the production of platform chemicals from various biological sources, including glycerol, lignin, cellulose, bio-oils, and sea products. It presents the results of catalytic and downstream processes involved in the conversion of these biomass-derived feedstocks. The experimental approaches are complemented by numerical descriptions, ranging from density functional theory (DFT) calculations to kinetic modellingof the experimental data. This multi-scale modelling approach helps to understand the underlying mechanisms and optimize the production of platform chemicals from renewable resources., (Copyright 2023 Blaž Likozar, Matej Žula, Andrii Kostyniuk, Edita Jasiukaitytė-Grojzdek , Giorgio Tofani, Ramesh Kumar Chowdari, Tina Ročnik Kozmelj, Žan Lavrič, Janvit Teržan, Brigita Hočevar, Filipa A. Vicente, Ana Oberlintner, Matej Huš, Davide Benedetto Tiz, Miša Mojca Cajnko, Dana Marinič, Emilija Rakić, Brett Pomeroy, Miha Grilc, Ana Jakob, Uroš Novak. License: This work is licensed under a Creative Commons Attribution 4.0 International License.)

Ethylene epoxidation is industrially and commercially one of the most important selective oxidations. Silver catalysts have been state-of-the-art for decades, their efficiency steadily improving with empirical discoveries of dopants and co-catalysts. Herein, we perform a computational screening of the metals in the periodic table, identify prospective superior catalysts and experimentally demonstrate that Ag/CuPb, Ag/CuCd and Ag/CuTl outperform the pure-Ag catalysts, while they still confer an easily scalable synthesis protocol. Furthermore, we show that to harness the potential of computationally-led discovery of catalysts fully, it is essential to include the relevant in situ conditions e.g., surface oxidation, parasitic side reactions and ethylene epoxide decomposition, as neglecting such effects leads to erroneous predictions. We combine ab initio calculations, scaling relations, and rigorous reactor microkinetic modelling, which goes beyond conventional simplified steady-state or rate-determining modelling on immutable catalyst surfaces. The modelling insights have enabled us to both synthesise novel catalysts and theoretically understand experimental findings, thus, bridging the gap between first-principles simulations and industrial applications. We show that the computational catalyst design can be easily extended to include larger reaction networks and other effects, such as surface oxidations. The feasibility was confirmed by experimental agreement., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Stereopure CF 3 -substituted syn -1,2-diols were prepared via the reductive dynamic kinetic resolution of the corresponding racemic α-hydroxyketones in HCO 2 H/Et 3 N. (Het)aryl, benzyl, vinyl, and alkyl ketones are tolerated, delivering products with ≥95% ee and ≥87:13 syn / anti . This methodology offers rapid access to stereopure bioactive molecules. Furthermore, DFT calculations for three types of Noyori-Ikariya ruthenium catalysts were performed to show their general ability of directing stereoselectivity via the hydrogen bond acceptor SO 2 region and CH/π interactions., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Dry reforming of methane (DRM) is a promising way to convert methane and carbon dioxide into H 2 and CO (syngas). CeO 2 nanorods, nanocubes, and nanospheres were decorated with 1-4 wt % Ni. The materials were structurally characterized using TEM and in situ XANES/EXAFS. The CO 2 activation was analyzed by DFT and temperature-programmed techniques combined with MS-DRIFTS. Synthesized CeO 2 morphologies expose {111} and {100} terminating facets, varying the strength of the CO 2 interaction and redox properties, which influence the CO 2 activation. Temperature-programmed CO 2 DRIFTS analysis revealed that under hydrogen-lean conditions mono- and bidentate carbonates are hydrogenated to formate intermediates, which decompose to H 2 O and CO. In excess hydrogen, methane is the preferred reaction product. The CeO 2 cubes favor the formation of a polydentate carbonate species, which is an inert spectator during DRM at 500 °C. Polydentate covers a considerable fraction of ceria's surface, resulting in less-abundant surface sites for CO 2 dissociation.

An increasingly utilized way for the production of propene is propane dehydrogenation. The reaction presents an alternative to conventional processes based on petroleum resources. In this work, we investigate theoretically how Cr 2 O 3 catalyzes this reaction in oxidative and reducing environments. Although previous studies showed that the reduced catalyst is selective for the non-oxidative dehydrogenation of propane, real operating conditions are oxidative. Herein, we use multiscale modeling to investigate the difference between the oxidized and reduced catalyst and their performance. The complete reaction pathway for propane dehydrogenation, including C-C cracking, formation of side products (propyne, ethane, ethylene, acetylene, and methane), and catalyst coking on oxidized and reduced surfaces of α-Cr 2 O 3 (0001), is calculated using density functional theory with the Hubbard correction. Parameters describing adsorption, desorption, and surface reactions are used in a kinetic Monte Carlo simulation, which employed industrially relevant conditions (700-900 K, pressures up to 2 bar, and varying oxidants: N 2 O, O 2 , and none). We observe that over the reduced surface, propene and hydrogen form with high selectivity. When oxidants are used, the surface is oxidized, which changes the reaction mechanism and kinetics. During a much faster reaction, H 2 O forms as a coproduct in a Mars-van Krevelen cycle. Additionally, CO 2 is also formed, which represents waste and adversely affects the selectivity. It is shown that the oxidized surface is much more active but prone to the formation of CO 2 , while the reduced surface is less active but highly selective toward propene. Moreover, the effect of the oxidant used is investigated, showing that N 2 O is preferred to O 2 due to higher selectivity and less catalyst coking. We show that there exists an optimum degree of surface oxidation, where the yield of propene is maximized. The coke, which forms during the reaction, can be burnt away as CO 2 with oxygen., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Chitin is the most abundant marine biopolymer, being recovered during the shell biorefining of crustacean shell waste. In its native form, chitin displays a poor reactivity and solubility in most solvents due to its extensive hydrogen bonding. This can be overcome by deacetylation. However, this process requires a high concentration of acids or bases at high temperatures, forming large amounts of toxic waste. Herein, we report on the first deacetylation with deep eutectic solvents (DESs) as an environmentally friendly alternative, requiring only mild reaction conditions. Biocompatible DESs are efficient in disturbing the native hydrogen-bonding network of chitin, readily dissolving it. First, quantum chemical calculations have been performed to evaluate the feasibility of different DESs to perform chitin deacetylation by studying their mechanism. Comparing these with the calculated barriers for garden-variety alkaline/acidic hydrolysis, which are known to proceed, prospective DESs were identified with barriers around 25 kcal·mol -1 or lower. Based on density functional theory results, an experimental screening of 10 distinct DESs for chitin deacetylation followed. The most promising DESs were identified as K 2 CO 3 :glycerol (K 2 CO 3 :G), choline chloride:acetic acid ([Ch]Cl:AA), and choline chloride:malic acid ([Ch]Cl:MA) and were subjected to further optimization with respect to the water content, process duration, and temperature. Ultimately, [Ch]Cl:MA showed the best results, yielding a degree of deacetylation (DDA) of 40% after 24 h of reaction at 120 °C, which falls slightly behind the threshold value (50%) for chitin to be considered chitosan. Further quantum chemical calculations were performed to elucidate the mechanism. Upon the removal of 40% N -acetyl groups from the chitin structure, its reactivity was considerably improved., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

As one of the most demanded dicarboxylic acids, adipic acid can be directly produced from renewable sources. Hexoses from (hemi)cellulose are oxidized to aldaric acids and subsequently catalytically dehydroxylated. Hitherto performed homogeneously, we present the first heterogeneous catalytic process for converting an aldaric acid into muconic and adipic acid. The contribution of leached Re from the solid pre-reduced catalyst was also investigated with hot-filtration test and found to be inactive for dehydroxylation. Corrosive or hazardous (HBr/H 2 ) reagents are avoided and simple alcohols and solid Re/C catalysts in an inert atmosphere are used. At 120 °C, the carboxylic groups are protected by esterification, which prevents lactonization in the absence of water or acidic sites. Dehydroxylation and partial hydrogenation yield monohexenoates (93 %). For complete hydrogenation to adipate, a 16 % higher activation barrier necessitates higher temperatures., (© 2020 The Authors. Published by Wiley-VCH GmbH.)

Propane (C 3 H 8 ) and butane (C 4 H 10 ) are short straight-chain alkane molecules that are difficult to convert catalytically. Analogous to propane, butane can be dehydrogenated to butenes (also known as butylenes) or butadiene, which are used industrially as raw materials when synthesizing various chemicals (plastics, rubbers, etc.). In this study, we present results of detailed first-principles-based multiscale modelling of butane dehydrogenation, consisting of three size- and time-scales. The reaction is modelled over Cr 2 O 3 (0001) chromium oxide, which is commonly used in the industrial setting. A complete 108-step reaction pathway of butane (C 4 H 10 ) dehydrogenation was studied, yielding 1-butene (CH 2 CHCH 2 CH 3 ) and 2-butene (CH 3 CHCHCH 3 ), 1-butyne (CHCCH 2 CH 3 ) and 2-butyne (CH 3 CCCH 3 ), butadiene (CH 2 CHCHCH 2 ), butenyne (CH 2 CHCCH), and ultimately butadiyne (CHCCCH). We include cracking and coking reactions (yielding C 1 , C 2 , and C 3 hydrocarbons) in the model to provide a thorough description of catalyst deactivation as a function of the temperature and time. Density functional theory calculations with the Hubbard U model were used to study the reaction on the atomistic scale, resulting in the complete energetics and first-principles kinetic parameters for the dehydrogenation reaction. They were cast in a kinetic model using mean-field microkinetics and kinetic Monte Carlo simulations. The former was used to obtain gas equilibrium conditions in the steady-state regime, which were fed in the latter to provide accurate surface kinetics. A full reactor simulation was used to account for the macroscopic properties of the catalytic particles: their loading, specific surface area, and density and reactor parameters: size, design, and feed gas flow. With this approach, we obtained first-principles estimates of the catalytic conversion, selectivity to products, and time dependence of the catalyst activity, which can be paralleled to experimental data. We show that 2-butene is the most abundant product of dehydrogenation, with selectivity above 90% and turn-over frequency above 10 -3 s -1 at T = 900 K. Butane conversion is below 5% at such low temperature, but rises above 40% at T > 1100 K. Activity starts to drop after ∼6 h because of surface poisoning with carbon. We conclude that the dehydrogenation of butane is a viable alternative to conventional olefin production processes., Competing Interests: The authors declare no competing financial interest., (© 2020 American Chemical Society.)

In this study, acidolysis of benzyl phenyl ether (BPE), being a representative lignin model compound with the α-O-4 linkage, was examined in γ-valerolactone (GVL) and a GVL/water mixture, each time acidified with sulfuric acid. The product distribution was strongly affected by water used as a cosolvent, which was found to be advantageous by inhibiting the formation of larger structures and introducing reactive OH groups instead. The experimental results indicate the GVL/water ratio as an important parameter to attain an optimal hydrolytic α-ether bond cleavage. Differences between the organosolv lignins (molecular weight distribution, OH group content, and structural features with reaction time), isolated under moderate reaction conditions, supported the findings obtained using BPE. A beneficial effect of the added water is reflected in the higher aliphatic OH group content and less intact structure. Analysis of the reaction mechanism represents an initial step toward kinetics and structure-activity correlation of biorefining industrial resources., Competing Interests: The authors declare no competing financial interest., (© 2020 American Chemical Society.)

The selective lignin conversion into bio-based organic mono-aromatics is a major general challenge due to complex structure itself/additional macromolecule modifications, caused by the cleavage of the ether chemical bonds during the lignocellulosic biomass organosolv pulping in acidified aqueous ethanol. Herein, the acido-lysis of connected benzyl phenyl (BPE), being a representative model compound with α-O-4 linkage, was investigated in methanol, EtOH and 75 vol% EtOH/water mixture solutions, progressing each time with protonating sulfuric acid. The effect of the physical solvent properties, acidity of the reaction process media and temperature on rate was determined. Experiments suggested BPE following S N 1 mechanism due to the formation of a stable primary carbocation/polarity. The product species distribution in non-aqueous functional alcohols was strongly affected. The addition of H 2 O was advantageous, especially for alkoxylation. Yield was reduced by a factor of 3, consequently preserving reactive hydroxyl group. Quantitative experimental results indicated key performance parameters to achieve optimum. Organosolv lignins were further isolated under significantly moderate conditions. Consecutive structural differences observed supported findings, obtained when using BPE. H 2 O presence was again found to grant a higher measured -OH content. Mechanistic pathway analysis thus represents the first step when continuing to kinetics, structure-activity relationships or bio-refining industrial resources.

In heterogeneous catalysis, bifunctional catalysts often outperform one-component catalysts. The activity is also strongly influenced by the morphology, size, and distribution of catalytic particles. For CO 2 hydrogenation, the size of the active copper area on top of the SrTiO 3 perovskite catalyst support can affect the activity, selectivity, and stability. Here, a detailed theoretical study of the effect of bifunctionality on an important chemical CO 2 transformation reaction, the reverse water gas shift (RWGS) reaction, is presented. Using density functional theory computation results for the RWGS pathway on three surfaces, namely, Cu(111), SrTiO 3 , and the Cu/SrTiO 3 interface between both solid phases, we construct the energy landscape of the reaction. The adsorbate-adsorbate lateral interactions are taken into account for catalytic surfaces, which show a sufficient intermediate coverage. The mechanism, combining all three surfaces, is used in mesoscale kinetic Monte Carlo simulations to study the turnover and yield for CO production as a function of particle size. It is shown that the reaction proceeds faster at the interface. However, including copper and the support sites in addition to the interface accelerates the conversion even further, showing that the bifunctionality of the catalyst manifests in a more complex interplay between the phases than just the interface effect, such as the hydrogen spillover. We identify three distinct effects, the electronic, cooperative, and geometric effects, and show that the surrounded smaller Cu features on the set of supporting SrTiO 3 show a higher CO formation rate, resulting in a decreasing RWGS model trend with the increasing Cu island size. The findings are in parallel with experiments, showing that they explain the previously observed phenomena and confirming the size sensitivity for the catalytic RWGS reaction., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

Substituted phenols are known to readily react with the hydroxyl radical (OH˙), which is the most powerful atmospheric oxidant and is also most often used in advanced oxidation processes (AOP) for wastewater treatment. We report temperature-dependent (278.15-318.15 K) second order kinetic rate constants for the aqueous-phase reactions of OH˙ with phenol and four substituted phenols: catechol, phloroglucinol, pyrogallol and 3-methylcatechol, with the last two measured for the first time. The constructed Hammett plots for mono- and di-substituted phenols have the potential to be further applied for predicting the reaction rate constants of other substituted phenols at 298.15 K. This will significantly facilitate the optimization of AOP and improve the predictive capabilities of atmospheric multiphase models in the future. Moreover, an advancement in the understanding of the underlying mechanism, i.e. OH˙ addition to the aromatic ring is made by theoretical calculations at the M06-2X level. We demonstrate that the position of substituents on the aromatic ring is important for the [OH-phenol]˙ adduct formation, which is supported by the experiment and theoretical calculations. Adjacent and nonadjacent electron donor/acceptor substituents differently impact the interplay between the activation energy and entropy. We also show that explicit solvation has to be accounted for in theoretical models in order to explicitly describe the formation of the transition state.

Many ambiguities surround the possible mechanisms of colored and toxic nitrophenols formation in natural systems. Nitration of a biologically and environmentally relevant aromatic compound, guaiacol (2-methoxyphenol), under mild aqueous-phase conditions (ambient temperatures, pH 4.5) was investigated by a temperature-dependent experimental modeling coupled to extensive ab initio calculations to obtain the activation energies of the modeled reaction pathways. The importance of dark nonradical reactions is emphasized, involving nitrous (HNO 2 ) and peroxynitrous (HOONO) acids. Oxidation by HOONO is shown to proceed via a nonradical pathway, possibly involving the nitronium ion (NO 2 + ) formation. Using quantum chemical calculations at the MP2/6-31++g(d,p) level, NO 2 • is shown capable of abstracting a hydrogen atom from the phenolic group on the aromatic ring. In a protic solvent, the corresponding aryl radical can combine with HNO 2 to yield OH • and, after a subsequent oxidation step, nitrated aromatic products. The demonstrated chemistry is especially important for understanding the aging of nighttime atmospheric deliquesced aerosol. The relevance should be further investigated in the atmospheric gaseous phase. The results of this study have direct implications for accurate modeling of the burden of toxic nitroaromatic pollutants, and the formation of atmospheric brown carbon and its associated influence on Earth's albedo and climate forcing.

Methylnitrocatechols (MNCs) are secondary organic aerosol (SOA) tracers and major contributors to atmospheric brown carbon; however, their formation and aging processes in atmospheric waters are unknown. To investigate the importance of aqueous-phase electrophilic substitution of 3-methylcatechol with nitronium ion (NO2(+)), we performed quantum calculations of their favorable pathways. The calculations predicted the formation of 3-methyl-5-nitrocatechol (3M5NC), 3-methyl-4-nitrocatechol (3M4NC), and a negligible amount of 3-methyl-6-nitrocatechol (3M6NC). MNCs in atmospheric PM2 samples were further inspected by LC/(-)ESI-MS/MS using commercial as well as de novo synthesized authentic standards. We detected 3M5NC and, for the first time, 3M4NC. In contrast to previous reports, 3M6NC was not observed. Agreement between calculated and observed 3M5NC/3M4NC ratios cannot unambiguously confirm the electrophilic mechanism as the exclusive formation pathway of MNCs in aerosol water. However, the examined nitration by NO2(+) is supported by (1) the absence of 3M6NC in the ambient aerosols analyzed and (2) the constant 3M5NC/3M4NC ratio in field aerosol samples, which indicates their common formation pathway. The magnitude of error one could make by incorrectly identifying 3M4NC as 3M6NC in ambient aerosols was also assessed, suggesting the importance of evaluating the literature regarding MNCs with special care.

A simple model is constructed to study the phase diagram and thermodynamic properties of methanol, which is described as a dimer of an apolar sphere mimicking the methyl group and a sphere with core-softened potential as the hydroxyl group. Performing classical Monte Carlo simulations, we obtained the phase diagram, showing a second critical point between two different liquid phases. Evaluating systems with a different number of particles, we extrapolate to infinite size in accordance with Ising universality class to obtain bulk values for critical temperature, pressure, and density. Strong evidence that the structure of the liquid changes upon transition from high- to low-density phase was provided. From the experimentally determined hydrogen bond strength and length in methanol and water, we propose where the second critical point of methanol should be.

Thermodynamic and structural properties of a coarse-grained model of methanol are examined by Monte Carlo simulations and reference interaction site model (RISM) integral equation theory. Methanol particles are described as dimers formed from an apolar Lennard-Jones sphere, mimicking the methyl group, and a sphere with a core-softened potential as the hydroxyl group. Different closure approximations of the RISM theory are compared and discussed. The liquid structure of methanol is investigated by calculating site-site radial distribution functions and static structure factors for a wide range of temperatures and densities. Results obtained show a good agreement between RISM and Monte Carlo simulations. The phase behavior of methanol is investigated by employing different thermodynamic routes for the calculation of the RISM free energy, drawing gas-liquid coexistence curves that match the simulation data. Preliminary indications for a putative second critical point between two different liquid phases of methanol are also discussed.