bluuebunny/crossref_metadata_2025_split huggingface dataset:
Status and Perspectives of Biomass Use for Industrial Process Heat for Industrialized Countries
Authors: Lenz Volker , Szarka Nora , Jordan Matthias , Thrän Daniela 
Published: May 2020

AbstractFull reduction of greenhouse gas emissions involves transforming the industrial process heat supply. The status and future perspectives of biomass for industrial heat mainly based on the German example are reviewed, and a more differentiated consideration by a newly introduced method is attempted. The article focuses on temperature levels above 200 °C combined with an individual examination of most energy‐consuming industrial subsectors according to the feasibility of biomass utilization. Numerous studies conclude that biomass use will shift substantially from residential to industrial heat. Results indicate that biomass could play a bigger role especially for cement and clinker production, but they indicate also a significant need for further research and development to take final conclusions.
pH Tuning of Water‐Soluble Arylazopyrazole Photoswitches
Authors: Ludwanowski Simon , Ari Meral , Parison Karsten , Kalthoum Somar , Straub Paula , Pompe Nils , Weber Stefan , Walter Michael , Walther Andreas 
Published: May 2020

AbstractArylazopyrazoles are an emerging class of photoswitches with redshifted switching wavelength, high photostationary states, long thermal half‐lives and facile synthetic access. Understanding pathways for a simple modulation of the thermal half‐lives, while keeping other parameters of interest constant, is an important aspect for out‐of‐equilibrium systems design and applications. Here, it is demonstrated that the thermal half‐life of a water‐soluble PEG‐tethered arylazo‐bis(o‐methylated)pyrazole (AAP) can be tuned by more than five orders of magnitude using simple pH adjustment, which is beyond the tunability of azobenzenes. The mechanism of thermal relaxation is investigated by thorough spectroscopic analyses and density functional theory (DFT) calculations. Finally, the concepts of a tunable half‐life are transferred from the molecular scale to the material scale. Based on the photochromic characteristics of E‐ and Z‐AAP, transient information storage is showcased in form of light‐written patterns inside films cast from different pH, which in turn leads to different times of storage. With respect to prospective precisely tunable materials and time‐programmed out‐of‐equilibrium systems, an externally tunable half‐life is likely advantageous over changing the entire system by the replacement of the photoswitch.
Evaluation of Pd→B Interactions in Diphosphinoborane Complexes and Impact on Inner‐Sphere Reductive Elimination
Authors: Ritter Florian , John Lukas , Schindler Tobias , Schroers Julian P. , Teeuwen Simon , Tauchert Michael E. 
Published: May 2020

AbstractThe dative Pd→B interaction in a series of RDPBR’ Pd0 and PdII complexes (RDPBR’=(o‐PR2C6H4)2BR’, diphosphinoborane) was analyzed using XRD, 11B NMR spectroscopy and NBO/NLMO calculations. The borane acceptor discriminates between the oxidation state PdII and Pd0, stabilizing the latter. Reaction of lithium amides with [(RDPBR’)PdII(4‐NO2C6H4)I] chemoselectively yields the C−N coupling product. DFT modelling indicates no significant impact of PdII→B coordination on the inner‐sphere reductive elimination rate.
Thermo‐Sensitive Dual‐Functional Nanospheres with Enhanced Lubrication and Drug Delivery for the Treatment of Osteoarthritis
Authors: Zhang Kuan , Yang Jielai , Sun Yulong , He Mingrui , Liang Jing , Luo Jing , Cui Wenguo , Deng Lianfu , Xu Xiangyang , Wang Bo , Zhang Hongyu 
Published: May 2020

AbstractOsteoarthritis is a typical degenerative joint disease related to a lubrication deficiency of articular cartilage, which is characterized by increased friction at the joint surface and severe inflammation of the joint capsule. Consequently, therapies combining lubrication restoration and drug intervention are regarded as a promising strategy for the treatment of osteoarthritis. In the present study, thermo‐sensitive dual‐functional nanospheres, poly[N‐isopropylacrylamide‐2‐methacryloyloxyethyl phosphorylcholine] (PNIPAM‐PMPC), are developed through emulsion polymerization. The PNIPAM‐PMPC nanospheres could enhance lubrication based on the hydration lubrication mechanism by forming a tenacious hydration layer surrounding the zwitterionic headgroups, and achieve local drug delivery by encapsulating the anti‐inflammatory drug diclofenac sodium. The lubrication and drug release tests showed improved lubrication and thermo‐sensitive drug release of the nanospheres. The in vitro test using cytokines‐treated chondrocytes indicated that the PNIPAM‐PMPC nanospheres were biocompatible and upregulated anabolic genes and simultaneously downregulated catabolic genes of the articular cartilage. In summary, the developed PNIPAM‐PMPC nanospheres, with the property of enhanced lubrication and local drug delivery, can be an effective nanomedicine for the treatment of osteoarthritis.
Exploring the Limits of π‐Acid Catalysis Using Strongly Electrophilic Main Group Metal Complexes: The Case of Zinc and Aluminium
Authors: Tian Jiaxin , Chen Yan , Vayer Marie , Djurovic Alexandre , Guillot Régis , Guermazi Refka , Dagorne Samuel , Bour Christophe , Gandon Vincent 
Published: May 2020

AbstractThe catalytic activity of cationic NHC‐ZnII and NHC‐AlIII (NHC=N‐heterocyclic carbene) complexes in reactions that require the electrophilic activation of soft C−C π bonds has been studied. The former proved able to act as a soft π‐Lewis acid in a variety of transformations. The benefit of the bulky IPr NHC ligand was demonstrated by comparison with simple ZnX2 salts. The tested NHC‐AlIII catalyst is not able to activate C−C π bonds but simple AlX2+ ions were found potent in some cases.
Oxidation of cis‐Diamminediacetato PtII with Hydrogen Peroxide Can Give Rise to Two Isomeric PtIV Products
Authors: Khattib D. , Ishan M. , Karmakar S. , Kostrhunova H. , Brabec V. , Gibson D. 
Published: May 2020

AbstractThe oxidation of cis‐[Pt(NH3)2(OAc)2] with H2O2 yields a mixture of two isomers: ctc‐[Pt(NH3)2(OH)2(OAc)2] and ctc‐[Pt(NH3)2(OH)(OAc)(OH)(OAc)]. Following modification with 4‐phenylbutyric (PhB) anhydride, two isomers were separated and characterized; the symmetric ctc‐[Pt(NH3)2(PhB)2(OAc)2] (1) and the nonsymmetric ctc‐[Pt(NH3)2(PhB)(OAc)(PhB)(OAc)] (2). They differ in their log P values and despite having similar cellular uptake and similar DNA platination levels, the symmetric ctc‐[Pt(NH3)2(OH)2(OAc)2] is more than 4‐fold more potent than the nonsymmetric isomer in a panel of 4 cancer cell lines.
Prebiotic Nucleoside Synthesis: The Selectivity of Simplicity
Authors: Kruse Florian M. , Teichert Jennifer S. , Trapp Oliver 
Published: May 2020

AbstractEver since the discovery of nucleic acids 150 years ago,[1] major achievements have been made in understanding and decrypting the fascinating scientific questions of the genetic code.[2] However, the most fundamental question about the origin and the evolution of the genetic code remains a mystery. How did nature manage to build up such intriguingly complex molecules able to encode structure and function from simple building blocks? What conditions were required? How could the precursors survive the unhostile environment of early Earth? Over the past decades, promising synthetic concepts were proposed providing clarity in the field of prebiotic nucleic acid research. In this Minireview, we show the current status and various approaches to answer these fascinating questions.
Transition‐Metal‐Free Coupling of 1,3‐Dipoles and Boronic Acids as a Sustainable Approach to C−C Bond Formation
Authors: Livingstone Keith , Bertrand Sophie , Kennedy Alan R. , Jamieson Craig 
Published: May 2020

AbstractThe need for alternative, complementary approaches to enable C−C bond formation within organic chemistry is an on‐going challenge in the area. Of particular relevance are transformations that proceed in the absence of transition‐metal reagents. In the current study, we report a comprehensive investigation of the coupling of nitrile imines and aryl boronic acids as an approach towards sustainable C−C bond formation. In situ generation of the highly reactive 1,3‐dipole facilitates a Petasis–Mannich‐type coupling via a nucleophilic boronate complex. The introduction of hydrazonyl chlorides as a complementary nitrile imine source to the 2,5‐tetrazoles previously reported by our laboratory further broadens the scope of the approach. Additionally, we exemplify for the first time the extension of this protocol into another 1,3‐dipole, through the synthesis of aryl ketone oximes from aryl boronic acids and nitrile N‐oxides.
Chiral Versus Non‐Chiral [MnIII6MnIINaI], [MnIII6MnII2NaI2] and [MnIII3MnIINaI] Clusters Derived from Schiff Bases or the Fight for Symmetry
Authors: Pilichos Evangelos , Escuer Albert , Font‐Bardia Mercé , Mayans Júlia 
Published: May 2020

AbstractThe reaction in basic media of manganese chloride with Schiff bases derived from the condensation of o‐vanillin with different chiral/racemic aminoalcohols yielded in a family of complexes in which the nuclearity, symmetry and magnetic behavior is controlled by changing the position of the chiral carbon. Chiral and racemic clusters with [MnIII6MnIINaI], [MnIII6MnII2NaI2] and [MnIII3MnIINaI] metallic core have been structurally and magnetically characterized. The racemic clusters with an odd number of chiral ligands exhibit the anomalous mixing of ligands with different conformation. Related racemic compounds have been reviewed.
Programming DNA‐Based Systems through Effective Molarity Enforced by Biomolecular Confinement
Authors: Rossetti Marianna , Bertucci Alessandro , Patiño Tania , Baranda Lorena , Porchetta Alessandro 
Published: May 2020

AbstractThe fundamental concept of effective molarity is observed in a variety of biological processes, such as protein compartmentalization within organelles, membrane localization and signaling paths. To control molecular encountering and promote effective interactions, nature places biomolecules in specific sites inside the cell in order to generate a high, localized concentration different from the bulk concentration. Inspired by this mechanism, scientists have artificially recreated in the lab the same strategy to actuate and control artificial DNA‐based functional systems. Here, it is discussed how harnessing effective molarity has led to the development of a number of proximity‐induced strategies, with applications ranging from DNA‐templated organic chemistry and catalysis, to biosensing and protein‐supported DNA assembly.
Halogen‐Bonded Assemblies of Arylene Imides and Diimides: Insight from Electronic, Structural, and Computational Studies
Authors: Mandal Kalyanashis , Bansal Deepak , Kumar Yogendra , Rustam  , Shukla Jyoti , Mukhopadhyay Pritam 
Published: May 2020

AbstractHalogen‐bonding interactions in electron‐deficient π scaffolds have largely been underexplored. Herein, the halogen‐bonding properties of arylene imide/diimide‐based electron‐deficient scaffolds were studied. The influence of scaffold size, from small (phthalimide) to moderately sized (pyromellitic diimide or naphthalenediimides) to large (perylenediimide), axial‐group modification, and number of halo substituents on the halogen bonding and its self‐assembly was probed in a set of nine compounds. The structural modification leads to tunable optical and redox properties. The first reduction potentialranges between −1.09 and −0.17 V (vs. SCE). Two of the compounds, that is,6and9, have deep‐lying LUMOs with values reaching −4.2 eV. Single crystals of all nine systems were obtained, which showed Br⋅⋅⋅O, Br⋅⋅⋅Br, or Br⋅⋅⋅π halogen‐bonding interactions, and a few systems are capable of forming all three types. These interactions lead to halogen‐bonded rings (up to 12‐membered), which propagate to form stacked 1D, 2D, or corrugated sheets. A few outliers were also identified, for example, molecules that prefer C−H⋅⋅⋅O hydrogen bonding over halogen bonding, or noncentrosymmetric rather than centrosymmetric organization. Computational studies based on Atoms in Molecules and Natural Bond Orbital analysis provided further insight into the halogen‐bonding interactions. This study can lead to a predictive design tool‐box to further explore related systems on surfaces reinforced by these weak directional forces.
Switching the Switch: Ligand Induced Disulfide Formation in HDAC8
Authors: Jänsch Niklas , Sugiarto Wisely Oki , Muth Marius , Kopranovic Aleksandra , Desczyk Charlotte , Ballweg Matthias , Kirschhöfer Frank , Brenner‐Weiss Gerald , Meyer‐Almes Franz‐Josef 
Published: May 2020

AbstractHuman histone deacetylase 8 is a well‐recognized target for T‐cell lymphoma and particularly childhood neuroblastoma. PD‐404,182 was shown to be a selective covalent inhibitor of HDAC8 that forms mixed disulfides with several cysteine residues and is also able to transform thiol groups to thiocyanates. Moreover, HDAC8 was shown to be regulated by a redox switch based on the reversible formation of a disulfide bond between cysteines Cys102 and Cys153. This study on the distinct effects of PD‐404,182 on HDAC8 reveals that this compound induces the dose‐dependent formation of intramolecular disulfide bridges. Therefore, the inhibition mechanism of HDAC8 by PD‐404,182 involves both, covalent modification of thiols as well as ligand mediated disulfide formation. Moreover, this study provides a deep molecular insight into the regulation mechanism of HDAC8 involving several cysteines with graduated capability to form reversible disulfide bridges.
Amphiphilic Polymeric Nanoparticles for Photoredox Catalysis in Water
Authors: Eisenreich Fabian , Meijer E. W. , Palmans Anja R. A. 
Published: May 2020

AbstractPhotoredox catalysis has recently emerged as a powerful synthesis tool in organic and polymer chemistry. In contrast to the great achievements realized in organic solvents, performing photocatalytic processes efficiently in aqueous media encounters several challenges. Here, it is presented how amphiphilic single‐chain polymeric nanoparticles (SCPNs) can be utilized as small reactors to conduct light‐driven chemical reactions in water. By incorporating a phenothiazine (PTH) catalyst into the polymeric scaffold, metal‐free reduction and C−C cross‐coupling reactions can be carried out upon exposure to UV light under ambient conditions. The versatility of this approach is underlined by a large substrate scope, tolerance towards oxygen, and excellent recyclability. This approach thereby contributes to a sustainable and green way of implementing photoredox catalysis.
Catalytic Asymmetric Total Synthesis of Exiguolide
Authors: Oka Kengo , Fuchi Shunsuke , Komine Keita , Fukuda Hayato , Hatakeyama Susumi , Ishihara Jun 
Published: May 2020

AbstractThe catalytic asymmetric total synthesis of (−)‐exiguolide, a complex 20‐membered macrolide embedded with a bis(tetrahydropyran) motif, is reported. The convergent synthesis involves the construction of the C1–C11 tetrahydropyran segment via catalytic asymmetric allylation and Prins cyclization, and the formation of the C12–C21 phosphonate segment via catalytic asymmetric cyclocondensation reaction and Johnson–Claisen rearrangement. The synthesis of 15‐epi‐exiguolide is also described.
Unprecedented Reverse Volume Expansion in Spin‐Transition Crystals
Authors: Guo Wenbin , Daro Nathalie , Pillet Sébastien , Marchivie Mathieu , Bendeif El‐Eulmi , Tailleur Elodie , Chainok Kittipong , Denux Dominique , Chastanet Guillaume , Guionneau Philippe 
Published: May 2020

AbstractThe current craze for research around the spin crossover phenomenon can be justified to some extent by the mechanical properties due to the decrease of volume associated with the transition of the metal ion from the HS state to the LS state. As demonstrated here, the molecular complex [Fe(PM‐pBrA)2(NCS)2] exhibits, on the contrary, an increase of the unit‐cell volume from HS to LS. This counter‐intuitive and unprecedented behavior that concerns both the thermal and the photoexcited spin conversions is revealed by a combination of single‐crystal and powder X‐ray diffraction complemented by magnetic measurements. Interestingly, this abnormal volume change appears concomitant with the wide rotation of a phenyl ring which induces a drastic modification, though reversible, of the structural packing within the crystal. In addition, the light‐induced HS state obtained through the Light‐Induced Excited Spin‐State Trapping shows a remarkably high relaxation temperature, namely T(LIESST), of 109 K, one of the highest so far reported. The above set of quite unusual characteristics opens up new fields of possibilities within the development of spin crossover materials.
From Bowls to Capsules: Assembly of Hexanuclear NiII Rings Tailored by Alkali Cations
Authors: Mayans Júlia , Stoumpos Constantinos C. , Font‐Bardia Mercé , Escuer Albert 
Published: May 2020

AbstractAn anionic hexanuclear NiII metallamacrocycle with endo and exo linking sites has been employed as a building block to generate a series of capsules and bowls of nanometric size. The supramolecular arrangement of the {Ni6} rings was tailored by the size of the alkali cations, showing the transition from {Ni6‐M2‐Ni6} capsules (M=LiI and NaI) to {Ni6‐M} bowls (M=KI and CsI). The alkyl co‐cations are determinant to stabilize the assemblies by means of CH⋅⋅⋅π interactions on the exo side of the metallamacrocycles. The effect on the topology of the supramolecular assemblies of the cation size, cation charge, Et3NH+ or Me4N+ counter cations has been analyzed. Magnetic measurements reveal the presence of ferromagnetic and antiferromagnetic interactions inside the rings that allow a S=0 ground state.
Synthesis of Highly Enantioenriched Sulfonimidoyl Fluorides and Sulfonimidamides by Stereospecific Sulfur–Fluorine Exchange (SuFEx) Reaction
Authors: Greed Stephanie , Briggs Edward L. , Idiris Fahima I. M. , White Andrew J. P. , Lücking Ulrich , Bull James A. 
Published: May 2020

AbstractSulfonimidamides present exciting opportunities as chiral isosteres of sulfonamides, with potential for additional directional interactions. Here, we present the first modular enantioselective synthesis of sulfonimidamides, including the first stereoselective synthesis of enantioenriched sulfonimidoyl fluorides, and studies on their reactivity. A new route to sulfonimidoyl fluorides is presented from solid bench‐stable, N‐Boc‐sulfinamide (Boc=tert‐butyloxycarbonyl) salt building blocks. Enantioenriched arylsulfonimidoyl fluorides are shown to be readily racemised by fluoride ions. Conditions are developed, which trap fluoride and enable the stereospecific reaction of sulfonimidoyl fluorides with primary and secondary amines (100 % es, es=enantiospecificity) generating sulfonimidamides with up to 99 % ee. Aryl and alkyl sulfonimidoyl fluoride reagents are suitable for mild late stage functionalisation reactions, exemplified by coupling with a selection of complex amines in marketed drugs.
An Ultra‐Microporous Metal–Organic Framework with Exceptional Xe Capacity
Authors: Chakraborty Debanjan , Nandi Shyamapada , Maity Rahul , Motkuri Radha Kishan , Han Kee Sung , Collins Sean , Humble Paul , Hayes James C. , Woo Tom K. , Vaidhyanathan Ramanathan , Thallapally Praveen K. 
Published: May 2020

AbstractMolecular confinement plays a significant effect on trapped gas and solvent molecules. A fundamental understanding of gas adsorption within the porous confinement provides information necessary to design a material with improved selectivity. In this regard, metal–organic framework (MOF) adsorbents are ideal candidate materials to study confinement effects for weakly interacting gas molecules, such as noble gases. Among the noble gases, xenon (Xe) has practical applications in the medical, automotive and aerospace industries. In this Communication, we report an ultra‐microporous nickel‐isonicotinate MOF with exceptional Xe uptake and selectivity compared to all benchmark MOF and porous organic cage materials. The selectivity arises because of the near perfect fit of the atomic Xe inside the porous confinement. Notably, at low partial pressure, the Ni–MOF interacts very strongly with Xe compared to the closely related Krypton gas (Kr) and more polarizable CO2. Further 129Xe NMR suggests a broad isotropic chemical shift due to the reduced motion as a result of confinement.
Interplay Between Planar and Spherical Aromaticity: Shielding Cone Behavior in Dual Planar‐Planar, Planar‐Spherical and Spherical‐Spherical Aromatics
Authors: Muñoz‐Castro Alvaro 
Published: May 2020

AbstractThe shielding cone concept is one of the most characteristic aspects of planar aromatic species. Herein, we explored how two neighbor aromatic moieties behave as dual planar‐planar, planar‐spherical, and spherical‐spherical species given by biphenyl, [PhCB11H11]−, and [CB11H11]22−, respectively. Our results show two separate aromatic regimes given by Clar's sextet and spherical aromatic states, with independent shielding cones sharing shielding regions of moderate strength, which can be extended for networks involving multiple independent aromatic states.
Flow Cytometry Assessment of Microalgae Physiological Alterations under CO2 Injection
Authors: Galotti Andréa , Jiménez‐Gómez Francisco , Parra Gema 
Published: May 2020

AbstractGrowth rate (GR), esterase activity (EA), membrane potential (MP), and DNA content were measured by flow cytometry to test if this powerful tool could be included in risk assessment and monitoring programs. This study tests a battery of endpoints that were measured on Scenedesmus (Acutodesmus) obliquus as model species, under high levels of injected CO2 to be proposed as biomarkers of effect. New technologies such as carbon capture and storage (CCS) bring positive consequences on CO2 mitigation strategies but also could have negative consequences if a CO2 leakage occurs during injection. Under this scenario, pH might drop down to 4 pH units around the pipe where the leakage happens. The study focus on to ascertain if the endpoints fulfill the requirements such as sensitiveness, be timely and cost‐effective, be easy to measure and interpret, and be nondestructive, valuable attributes in effective biomarkers. CO2 injected at high levels significantly affects the EA, the membrane polarization, as well as GRs. However the DNA content did not shown a clear response under this condition. In conclusion, the GR, the EA, and the MP analyzed by flow cytometry fulfilled the attributes mentioned above and are proposed as biomarkers of effect in CCS monitoring programs. © 2020 International Society for Advancement of Cytometry