Excited-state Aromaticity of Gold(III) Hexaphyrins with Metalation Effect Investigated by Time-resolved Electronic & Vibrational Spectroscopies.
Excited-state Aromaticity of Gold(III) Hexaphyrins with Metalation Effect Investigated by Time-resolved Electronic & Vibrational Spectroscopies. Angew Chem Int Ed Engl. 2020 Jan 18;: Authors: Kim D, Kim J, Oh J, Soya T, Yoneda T, Park S, Lim M, Osuka A Abstract Expanded porphyrins with proper metalation provided us with an excellent opportunity to study excited-state aromaticity. The coordinated metal helped us to observe the excited-state aromaticity in the triplet state by the heavy atom effect, but other metalation effects on the excited-state aromaticity were ambiguous. Here, the excited-state...
Source: Angewandte Chemie - January 18, 2020 Category: Chemistry Authors: Kim D, Kim J, Oh J, Soya T, Yoneda T, Park S, Lim M, Osuka A Tags: Angew Chem Int Ed Engl Source Type: research

Visible Light-Assisted Gold-Catalyzed Fluoroarylation of Allenoates.
Abstract A strategically novel synthetic method for the fluoroarylation of allenic ester was successfully developed, which enables an expedient construction of a host of β-fluoroalkyl-containing cinnamate derivatives. By resorting to visible light-promoted gold redox catalysis, this reaction proceeds smoothly under very mild reaction conditions, accommodates a large variety of functional groups, and more importantly allows the incorporation of fluorine and aryl groups in excellent regio- and stereoselectivity. The concomitant activation mode for both allene motif and hydrogen fluoride is ascribed as the key f...
Source: Angewandte Chemie - January 18, 2020 Category: Chemistry Authors: Tang HJ, Zhang X, Zhang YF, Feng C Tags: Angew Chem Int Ed Engl Source Type: research

Anchored mediator enabling shuttle-free redox mediation in lithium-oxygen batteries.
Abstract Redox mediators (RMs) are considered an effective countermeasure to reduce the large polarization in lithium-oxygen batteries. Nevertheless, achieving sufficient enhancement of the cyclability is limited by the trade-offs of freely mobile RMs, which are beneficial for charge transport but also trigger the shuttling phenomenon. Here, we successfully decoupled the charge-carrying redox property of RMs and shuttling phenomenon by anchoring the RMs in polymer form, where physical RM migration was replaced by charge transfer along polymer chains. Using a model system of a polymer, PTMA (2,2,6,6-tetramethyl-1-p...
Source: Angewandte Chemie - January 18, 2020 Category: Chemistry Authors: Ko Y, Park H, Lee K, Kim SJ, Park H, Bae Y, Kim J, Park SY, Kwon JE, Kang K Tags: Angew Chem Int Ed Engl Source Type: research

Ruthenium-Catalyzed Direct Asymmetric Reductive Amination of Diaryl and Sterically Hindered Ketones with Ammonium Salts and H2.
Abstract Transition metal-catalyzed direct asymmetric reductive amination (ARA) of diaryl or sterically hindered ketones remains unknown and an open challenge. Herein, Ru-catalyzed direct asymmetric reductive amination of ortho -OH-substituted diaryl and sterically hindered ketones with ammonium salts has been disclosed for the first time, offering a straightforward route toward the synthesis of synthetically useful chiral primary diarylmethylamines and sterically hindered benzylamines (up to 97% yield, 93->99% ee). The elaborations of chiral amine products into bioactive compounds have been exhibited through m...
Source: Angewandte Chemie - January 17, 2020 Category: Chemistry Authors: Hu LA, Zhang Y, Zhang QW, Yin Q, Zhang X Tags: Angew Chem Int Ed Engl Source Type: research

Chemical Synthesis and Immunological Evaluation of Pertussis-Like Pentasaccharide Bearing Multiple Rare Sugars as a Potential Anti-pertussis Vaccine.
Abstract The 60-year high Bordetella pertussis ( B. pertussis ) infection rate in the world suggests the urgent need for new anti-pertussis vaccines. Lipopolysaccharide (LPS) of B. pertussis is an attractive antigen for vaccine development. With the presence of multiple rare sugars and unusual glycosyl linkages, B. pertussis LPS is a highly challenging synthetic target. In this work, aided by molecular dynamics simulation and modeling, the pertussis LPS like pentasaccharide was chemically synthesized for the first time. The pentasaccharide was conjugated with a powerful carrier, bacteriophage Qβ as a vaccine ...
Source: Angewandte Chemie - January 17, 2020 Category: Chemistry Authors: Wang P, Huo CX, Lang S, Caution K, Nick ST, Dubey P, Deora R, Huang X Tags: Angew Chem Int Ed Engl Source Type: research

Multivariate Modulation of the Zr MOF UiO-66 for Defect-Controlled Multimodal Anticancer Drug Delivery.
Abstract Metal-organic frameworks (MOFs) are emerging as leading candidates for nanoscale drug delivery, as a consequence of their high drug capacities, ease of functionality, and the ability to carefully engineer key physical properties. Despite many anticancer treatment regimens consisting of a cocktail of different drugs, examples of delivery of multiple drugs from one MOF are rare, potentially hampered by difficulties in postsynthetic loading of more than one cargo molecule. Herein, we report a new strategy, multivariate modulation, which allows incorporation of up to three drugs in the Zr MOF UiO-66 by defect...
Source: Angewandte Chemie - January 17, 2020 Category: Chemistry Authors: Abanades Lazaro I, Wells C, Forgan RS Tags: Angew Chem Int Ed Engl Source Type: research

Highly Selective Separation of Minimum-Boiling Azeotrope Toluene/Pyridine by Nonporous Adaptive Crystals of Cucurbit[6]uril.
Abstract The production of high purity toluene and pyridine is of significance in both industrial production and synthetic chemistry. The present protocols available to separate toluene/pyridine mixtures are several energy-intensive distillation methods, which are not environmently-friendly and cost-effective. Here we provide an energy-efficient and simple adsorptive separation protocol using nonporous adaptive crystals of cucurbit[6]uril ( Q[6] ). Q[6] crystals separate pyridine from toluene/pyridine mixtures with nearly 100% purity. Furthermore, removal of guest from guest-loaded Q[6] leads to the guest-free cuc...
Source: Angewandte Chemie - January 17, 2020 Category: Chemistry Authors: Li Q, Jie K, Huang F Tags: Angew Chem Int Ed Engl Source Type: research

Oxidative addition of alkenyl and alkynyl iodides to a Au(I) complex.
Abstract The first isolated examples of intermolecular oxidative addition of alkenyl and alkynyl iodides to Au(I) are reported. Using a 5,5'-difluoro-2,2'-bipyridyl ligated complex, oxidative addition of geometrically defined alkenyl iodides occurs readily, reversibly and stereospecifically to give alkenyl-Au(III) complexes. Conversely, reversible alkynyl iodide oxidative addition generates bimetallic complexes containing both Au(III) and Au(I) centers. Stoichiometric studies show that both new initiation modes can form the basis for the development of C-C bond forming cross-couplings. PMID: 31951062 [PubMed ...
Source: Angewandte Chemie - January 17, 2020 Category: Chemistry Authors: Russell CA, Bower J, Cadge J, Sparkes H Tags: Angew Chem Int Ed Engl Source Type: research

Low-fouling Fluoropolymers for Bioconjugation and In Vivo Tracking.
Abstract The conjugation of hydrophilic low-fouling polymers to therapeutic molecules and particles is an effective approach to improving their aqueous stability and solubility, and extending their pharmacokinetics. Recent concerns over the immunogenicity of poly(ethylene glycol) has highlighted the importance of identifying alternative low fouling polymers. Herein, we report a new class of synthetic water-soluble homo-fluoropolymers with a sulfoxide side-chain structure. The incorporation of fluorine enables direct imaging of the homopolymer by 19 F MRI, negating the need for additional synthetic steps to attach ...
Source: Angewandte Chemie - January 17, 2020 Category: Chemistry Authors: Fu C, Demir B, Alcantara S, Kumar V, Han F, Kelly H, Tan X, Yu Y, Xu W, Zhao J, Zhang C, Peng H, Boyer C, Woodruff T, Kent S, Searles D, Whittaker A Tags: Angew Chem Int Ed Engl Source Type: research

Tuning Cellular Biological Functions Through the Controlled Release of NO from a Porous Ti-MOF.
Abstract Materials for the controlled release of nitric oxide (NO) are of interest for therapeutic applications. However, to date, many suffer from toxicity and stability issues, as well as poor performance. Herein, we propose a new NO adsorption/release mechanism through the formation of nitrites on the skeleton of a titanium-based Metal-Organic Framework (MOF) that we have named MIP-177, featuring a suitable set of properties for such applications: (i) high NO storage capacity (3 µmol mg -1 solid ), (ii) excellent biocompatibility at therapeutic relevant concentrations (no cytotoxicity at 90 µg/mL fo...
Source: Angewandte Chemie - January 17, 2020 Category: Chemistry Authors: Pinto RV, Wang S, Tavares S, Pires J, Antunes F, Vimont A, Clet G, Daturi M, Maurin G, Serre C, Pinto ML Tags: Angew Chem Int Ed Engl Source Type: research

The crucial role of charge accumulation and spin polarization in activating carbon-based catalysts for electrocatalytic nitrogen reduction.
Abstract Cost-effective carbon-based catalysts are promising for catalyzing electrochemical N 2 reduction reaction (NRR). However, the activity origin of carbon-based catalysts towards NRR remains unclear, and regularities and rules in rational design carbon-based NRR electrocatalysts are still lacking. Here, based on a combination of theoretical calculations and experimental observations, we systematically evaluated the chalcogen/oxygen group elements (O, S, Se, and Te) doped carbon materials as potential NRR catalysts. We revealed that heteroatom-doping induced charge accumulation facilitates N 2 adsorption on c...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Ling T, Yang Y, Zhang L, Hu Z, Zheng Y, Tang C, Chen P, Wang R, Qiu K, Mao J, Qiao SZ Tags: Angew Chem Int Ed Engl Source Type: research

Continuous-Flow Extraction of Adjacent Metals - a Disruptive Economic Window for In-Situ Resource Utilization of Asteroids?
Abstract For in-situ resource utilization (ISRU), the cost-mass conundrum needs to be solved, before any other formidable challenges may be tackled. Technologies may need to be conceptualised from first principals, rather than taking the most advanced technology of today. Using this approach, this paper seeks to provide a think tank about how chemical process intensification can help with technology and business case disruption of ISRU matters, how this might influence Space-industry start-ups, and first of all even Earth-industry transformations. The disruptive technology considered is continuous micro-flow solve...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Hessel V, Tran NN, Orandi S, Asrami MR, Goodsite ME, Nguyen H Tags: Angew Chem Int Ed Engl Source Type: research

Polyhydrazide-based organic nanotubes as extremely efficient and highly selective artificial iodide channels.
We report herein a series of pore-containing polymeric nanotubes based on an H-bonded hydrazide backbone. Nanotubes of suitable lengths, possessing a hollow cavity of ~ 6.5 Å in diameter, are interestingly found to mediate highly efficient transport of diverse types of anions, rather than cations, across lipid membrane. Polymer channel 1a , having an averaged molecular weight of 18.2 KDa and 3.6 nm in helical height, exhibits the highest anion transport activities with iodide ( EC 50 = 0.042 uM or 0.028 mol% relative to lipid) being transported 10 times more efficiently than chlorides ( EC 50 = 0.47 uM). Notably, eve...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Zeng H, Roy A, Joshi H, Ye R, Shen J, Chen F, Aksimentiev A Tags: Angew Chem Int Ed Engl Source Type: research

Oppositely Charged Ti3C2Tx MXene Membranes with 2D Nanofluidic Channels for Osmotic Energy Harvesting.
Abstract Membrane-based reverse electrodialysis (RED) is considered as the most promising technique to harvest osmotic energy. However, the traditional membranes are limited by the high internal resistance and low efficiency, resulting in undesirable power densities. Here, we report the combination of oppositely charged Ti 3 C 2 T x MXene membranes (MXMs) with confined 2D nanofluidic channels as high-performance osmotic power generators. The negatively or positively charged 2D MXene nanochannels exhibit typical surface-charge-governed ion transport and show excellent cation or anion selectivity. By mixing the arti...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Ding L, Xiao D, Lu Z, Deng J, Wei Y, Caro J, Wang H Tags: Angew Chem Int Ed Engl Source Type: research

NiH-Catalyzed Migratory Defluorinative Cross Olefin-Coupling: Trifluoromethyl-Substituted Alkenes as Acceptor Olefins to Form gem-Difluoroalkenes.
We report a nickel hydride-catalyzed migratory defluorinative coupling between two electronically-differentiated olefins. A broad scope of unactivated donor olefins can be joined directly to acceptor olefins containing an electron-deficient trifluoro-methyl-substituent in both intra- and intermolecular fashions to form gem -difluoroalkenes. This migratory coupling has both site- and chemoselectivity under mild conditions, with the formation of a tertiary or quaternary carbon center. PMID: 31951070 [PubMed - as supplied by publisher] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Chen F, Xu X, He Y, Huang G, Zhu S Tags: Angew Chem Int Ed Engl Source Type: research

Recent Insights into Heavy-Atom Tunneling in Organic Reactions.
Abstract In the past few years numerous investigations have been reported on the role of heavy-atom tunneling in the area of pericyclic reactions, π-bond shifting, and other processes. These studies illustrate unique strategies for experimental detection of heavy-atom tunneling and the increased use of calculations to predict tunneling.  This Minireview focuses primarily on carbon tunneling in ground-state processes but also highlights nitrogen tunneling and the first example of excited-state heavy-atom tunneling. Salient features of these reactions along with potential limitations are discussed, as well a...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Castro C, Karney WL Tags: Angew Chem Int Ed Engl Source Type: research

How Lewis Acids Catalyze Diels-Alder Reactions.
pt FM Abstract The Lewis acid (LA)-catalyzed Diels-Alder reaction between isoprene and methyl acrylate was investigated quantum chemically using a combined density functional theory and coupled-cluster theory approach. Computed activation barriers systematically decrease as the strength of the LA increases along the series I 2 
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Vermeeren P, Hamlin TA, Fernández I, Bickelhaupt FM Tags: Angew Chem Int Ed Engl Source Type: research

Mechanical Force Induces Ylide-Free Cycloaddition of Nonscissible Aziridines.
Abstract Reported herein is that aziridines can be a nonvulnerable mechanophore. Upon exposure to a mechanical force, stereochemically pure nonactivated aziridines incorporated into the backbone of macromolecule do not undergo cis-trans isomerization, evidencing no bond cleavage by the force. Nonetheless, aziridines react with a dipolarophile and does not obey conventional reaction pathways that involve C-C or C-N bond cleavage prior to the event of cycloaddition. The mechanism of such an ylide-free reaction of aziridines is explained by calculations. Our work demonstrates that a nonvulnerable chemical structure c...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Yoon HJ, Jung S Tags: Angew Chem Int Ed Engl Source Type: research

Hollow Multi-Shelled Structure Benefited Charge Transport and Active Sites for Li-Ion Capacitors.
Abstract Lithium ion capacitor (LIC) has attracted tremendous research interest, because it meets both the requirement on high energy and power densities. The balance between effective surface areas and mass transport is highly desired to fabricate the optimized electrode material for LIC. In this paper, triple-shelled (3S) Nb 2 O 5 hollow multi-shelled structure (HoMS) were synthesized for the first time through the sequential templating approach and then applied for the anode of LIC. The unique structure of HoMS, such as large efficient surface area, hierarchical pores, and multiple shells, provides abundant rea...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Wang D Tags: Angew Chem Int Ed Engl Source Type: research

Large deformation of a DNA origami nanoarm through the cumulative actuation of tension-adjustable modules.
Abstract Making use of the programmability and structural flexibility of the DNA molecule, we designed a DNA origami nanoarm capable of undergoing large deformation. Our DNA origami nanoarm comprised serially repeated tension-adjustable modules, the cumulative actuation of which resulted in a large deformation of the arm structure, which transformed from a linear shape into an arched shape. Combining atomic force microscopy imaging and theoretical analyses based on the mechanics of materials, we demonstrate that the degree of deformation can be systematically controlled by merely replacing a set of strands that is...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Suzuki Y, Kawamata I, Mizuno K, Murata S Tags: Angew Chem Int Ed Engl Source Type: research

Direct Evidence for Remote Participation in Galactose Building Blocks during Glycosylations Revealed by Cryogenic Vibrational Spectroscopy.
Abstract The stereoselective formation of 1,2- cis -glycosidic bonds is challenging. However, 1,2- cis -selectivity can be induced by remote participation of C4 or C6 ester groups. Reactions involving remote participation are believed to proceed via a key ionic intermediate, the glycosyl cation. Although mechanistic pathways were postulated many years ago, the structure of the reaction intermediates remained elusive due to their short-lived nature. Here, we unravel the structure of glycosyl cations involved in remote participation reactions via cryogenic vibrational spectroscopy and first principles theory. Acetyl...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Marianski M, Mucha E, Greis K, Moon S, Pardo A, Kirschbaum C, Thomas D, Meijer G, von Helden G, Gilmore K, Seeberger P, Pagel K Tags: Angew Chem Int Ed Engl Source Type: research

In Situ Reconstruction of Hierarchical Sn-Cu/SnOx Core/Shell Catalyst for High-Performance CO2 Electroreduction.
Abstract Electrochemical CO 2 reduction reaction (CO 2 RR) into valuable C 1 (formate and CO) products has been identified as one of the most techno-economically achievable strategies for alleviating CO 2 emissions. However, high C 1 Faradaic efficiency and stability are generally attained at high overpotential and low current density. Herein, we demonstrate that the SnO x shell in Sn 2.7 Cu catalyst with hierarchical Sn-Cu core can be in situ reconstructed under cathodic potentials of CO 2 RR. The resulting Sn 2.7 Cu catalyst achieves a high current density of 406.7±14.4 mA cm -2 with C 1 Faradaic efficien...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Ye K, Zhou Z, Shao J, Lin L, Gao D, Ta N, Si R, Wang G, Bao X Tags: Angew Chem Int Ed Engl Source Type: research

Development of Cross-Conjugated Vinylogous [4+2] Anionic Annulation. Application to the Total Synthesis of Natural Antibiotic ( ±)-ABX.
Development of Cross-Conjugated Vinylogous [4+2] Anionic Annulation. Application to the Total Synthesis of Natural Antibiotic (±)-ABX. Angew Chem Int Ed Engl. 2020 Jan 16;: Authors: Shia KS, Huang JK Abstract The cross-conjugated vinylogous [4+2] anionic annulation has been newly developed, the cascade process of which has a high preference for regiochemical control and chemoselectivity, giving rise to exclusively Michael-type adducts in moderate to high yields (up to 94%, 35 examples). By making use of this approach as a key operation, the first total synthesis of natural antibiotic ABX, in ra...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Shia KS, Huang JK Tags: Angew Chem Int Ed Engl Source Type: research

Triple Helix Stabilizing Effects in Collagen Model Peptides Containing PPII Helix-Preorganized Diproline Modules.
n U Abstract Collagen model peptides (CMPs) serve as tools for under-standing stability and function of the collagen triple helix and have a potential for biomedical applications. In the past, inter-strand cross-linking or conformational preconditioning of proline units through stereoelectronic effects have been utilized in the design of stabilized CMPs. To further study the effects determining collagen triple helix stability we investigated a series of CMPs containing synthetic diproline-mimicking modules (ProMs), which are preorganized in a PPII helix-type conformation by a functionalizable intra-strand C2-bridg...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Schmalz HG, Maassen A, Gebauer J, Abraham ET, Grimm I, Neudörfl JM, Neundorf I, Baumann U Tags: Angew Chem Int Ed Engl Source Type: research

Electrochemiluminescence Waveguide in Single Crystalline Molecular Wires.
Abstract Here we report the first observation of active waveguide of electrochemiluminescence (ECL) in single crystalline molecular wires self-assembled from cyclometalated iridium(III) complexes, namely tris(1-phenylisoquinoline-C2,N ) (Ir(piq)3). Under dark conditions, the molecular wires deposited on the electrode surface can act as both ECL emitters and active waveguides. As revealed by ECL microscopy, the molecular wires exhibit the typical characteristics of optical waveguides, transmitting ECL and generating much brighter ECL emission at their terminals. Moreover, self-generated ECL can be confined inside t...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Guo W, Ding H, Zhou P, Wang Y, Su B Tags: Angew Chem Int Ed Engl Source Type: research

Probing long-range anisotropic interactions - A general and sign-sensitive strategy to measure 1H-1H residual dipolar couplings as a key advance for organic structure determination.
Abstract Residual dipolar couplings (RDCs) are amongst the most powerful NMR parameters for organic structure elucidation. In order to maximize their effectiveness in increasingly complex cases such as flexible compounds, a maximum of RDCs between nuclei sampling a large distribution of orientations is needed, including sign information. For this, the easily accessible one-bond 1 H- 13 C RDCs alone often fall short. Long-range 1 H- 1 H RDCs are both abundant and typically sample highly complementary orientations, but accessing them in a sign-sensitive way has been severely obstructed due to the overflow of 1 H- 1 ...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Sinnaeve D, Ilgen J, Di Pietro ME, Primozic JJ, Schmidts V, Thiele CM, Luy B Tags: Angew Chem Int Ed Engl Source Type: research

Multi-Photon Excitation in Photoredox Catalysis: Concepts, Applications, Methods.
Abstract The energy of visible photons and the accessible redox potentials of common photocatalysts set thermodynamic limits to photochemical reactions that can be driven by traditional visible-light irradiation. UV excitation can be damaging and induce side reactions, hence visible or even near-IR light is usually preferable. Thus, photochemistry currently faces two divergent challenges, namely the desire to perform ever more thermodynamically demanding reactions with increasingly lower photon energies. The pooling of two low-energy photons can address both challenges simultaneously, and whilst multi-photon spect...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Glaser F, Kerzig C, Wenger OS Tags: Angew Chem Int Ed Engl Source Type: research

Phosphonium boranes for the selective transport of fluoride anions across artificial phospholipid membranes.
Abstract With the view of developing selective transmembrane anion transporters, we have evaluated a series of phosphonium boranes of general formula [p-RPh2P(C6H4)BMes2]+ whose structure differs by the nature of the R group appended to the phosphorus atom.  Our results demonstrate that variation of this R group informs the lipophilicity of these compounds, their Lewis acidity as well as their transport activity.  Anion transport experiments in POPC-based large unilamellar vesicles show that these main group cations are highly selective for the fluoride anion which is transported more than 20 times faste...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Gabbai FP Tags: Angew Chem Int Ed Engl Source Type: research

Coenzymes and their role in the evolution of Life.
Abstract The evolution of coenzymes, or the impact of coenzymes on the origin of Life, is fundamental for understanding our own existence and yet, this topic is rarely discussed in contemporary science. Coenzymes are small molecules that occupy an elementary role with respect to chemical reactivity and selectivity when associated with a macromolecular template. They are essential for functional biocatalysis in all living organisms and act as currency to regulate many basic metabolic processes. Having established reasonable hypotheses about the emergence of prebiotic chemical building blocks, which were probably cr...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Kirschning A Tags: Angew Chem Int Ed Engl Source Type: research

Molecular Porous Photosystems Tailored for Long-Term Photocatalytic CO2 Reduction.
Abstract Herein, we report the molecular-level structuration of two full photosystems into conjugated porous organic polymers. The strategy of heterogenization gives rise to photosystems which are still fully active after 4 days of continuous illumination. Those materials catalyse the carbon dioxide photoreduction driven by visible light to produce up to three grams of formate per gram of catalyst. The covalent tethering of the two active sites into a single framework is shown to play a key role in the visible light activation of the catalyst. The unprecedented long-term efficiency arises from an optimal photoindu...
Source: Angewandte Chemie - January 16, 2020 Category: Chemistry Authors: Wisser FM, Duguet M, Perrinet Q, Ghosh AC, Alves-Favaro M, Mohr Y, Lorentz C, Quadrelli EA, Palkovits R, Farrusseng D, Mellot-Draznieks C, De Waele V, Canivet J Tags: Angew Chem Int Ed Engl Source Type: research

Bridging Ultrasmall Au Clusters into the Pores of a Covalent Organic Framework for Enhanced Photostability and Photocatalytic Performance.
Abstract Gold (Au) clusters loading on various supports were widely used in the fields of energy and biology. However, the poor photostability of Au clusters on support interface under longtime illumination usually results in loss of catalytic performance. Covalent organic frameworks (COFs ) with periodic and ultrasmall pore structures are ideal supports for dispersing and stabilizing Au clusters, while it is difficult to encapsulate Au clusters into the ultrasmall pore structures. Herein, a two-dimensional (2D) COF modified with thiol chains (-SH) in its pores was prepared. Taking -SH as nucleation sites, Au NCs ...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Deng Y, Zhang Z, Du P, Ning X, Wang Y, Zhang D, Liu J, Zhang S, Lu X Tags: Angew Chem Int Ed Engl Source Type: research

Luminescent Tetradentate Gold(III)-TADF Emitters: Microwave-Assisted Synthesis and High Performance OLEDs With EQEs Up To 25 % and Long Operational Lifetime.
Abstract Structurally robust tetradentate gold(III)-emitters have potent material applications but are rare and unprecedented for those displaying thermally activated delayed fluorescence (TADF). In this work, a novel synthetic route leading to the preparation of highly emissive, charge-neutral tetradentate [C^C^N^C] gold(III) complexes with 5-5-6 membered chelate rings has been developed through microwave-assisted C-H bond activation. These complexes show high thermal stability and with emission origin ( 3 IL, 3 ILCT and TADF) tuned by varying the substituents of the C^C^N^C ligand. With phenoxazine/diphenylamine...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Zhou D, To WP, Tong GSM, Cheng G, Du L, Phillips DL, Che CM Tags: Angew Chem Int Ed Engl Source Type: research

A Scalable, Metal-, Azide- and Halogen-Free Method for the Preparation of Triazoles.
Abstract A scalable, metal-, azide- and halogen-free method for the synthesis of substituted 1,2,3-triazoles has been developed. The reaction proceeds through a 3-component coupling of α-ketoacetals, tosyl hydrazide, and a primary amine. Functional group tolerance is outstanding in both the α-ketoacetal and amine coupling partners providing access to 4-, 1,4-, 1,5-, and 1,4,5- substituted triazoles in excellent yield. This robust method results in densely functionalised 1,2,3-triazoles that remain challenging to prepare by azide-alkyne cycloaddition (AAC, CuAAC, RuAAC) methods and can be scaled in eith...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Clark P, Williams GD, Hayes JF, Tomkinson NCO Tags: Angew Chem Int Ed Engl Source Type: research

Achieving Efficient Multichannel Conductance in Through-Space Conjugated Single-Molecule Parallel Circuits.
Abstract According to Landauer's theory, constructing single-molecule parallel circuits with multiple conducting channels is an effective strategy to improve conductance of a single molecular junction. However, the reports on single-molecule parallel circuits are extremely rare. Herein, we report a novel through-space conjugated single-molecule parallel circuit ( f -4Ph-4SMe) comprised of a pair of closely parallel aligned p -quaterphenyl chains tethered by a vinyl bridge and end-capped with four methylmercapto (SMe) anchors. Scanning tunneling microscopy-based break junction (STM-BJ) technique and transmission ca...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Shen P, Huang M, Qian J, Li J, Ding S, Zhou XS, Xu B, Zhao Z, Tang BZ Tags: Angew Chem Int Ed Engl Source Type: research

A Structurally Characterized Cobalt(I)  σ-Alkane Complex.
A Structurally Characterized Cobalt(I) σ-Alkane Complex. Angew Chem Int Ed Engl. 2020 Jan 15;: Authors: Boyd TM, Tegner B, Tizzard G, Martinez-Martinez A, Neale S, Hayward M, Coles S, Macgregor S, Weller AS Abstract The synthesis, and x-ray structure, of a cobalt  s -alkane complex, [Co(Cy 2 P(CH 2 ) 4 PCy 2 )( norbornane )][BAr F 4 ], is achieved by a single-crystal to single-crystal solid/gas hydrogenation from a norbornadiene precursor. Magnetic data show this complex to be a triplet. Periodic DFT and electronic structure analyses identify weak C-H ··· Co&n...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Boyd TM, Tegner B, Tizzard G, Martinez-Martinez A, Neale S, Hayward M, Coles S, Macgregor S, Weller AS Tags: Angew Chem Int Ed Engl Source Type: research

Amphiphilic Polyphenylene Dendron Conjugates for Surface Remodeling of Adenovirus 5.
We report the synthesis of amphiphilic polyphenylene dendrimer branches (dendrons) providing alternating hydrophilic and lipophilic surface groups and one reactive enthynyl group at the core. The amphiphilic surface groups serve as biorecognition units that bind to the surface of adenovirus 5 (Ad5), which is one of the most common vectors in gene therapy. The Ad5/dendron complexes showed high gene transduction efficiencies in coxsackie-adenovirus receptor (CAR)-negative cells. Moreover, the dendrons offer incorporating new functions at the dendron core by in situ post-modifications even when bound to the Ad5 surface. In th...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Wagner J, Li L, Simon J, Landfester K, Mailänder V, Müllen K, Ng DYW, Wu Y, Weil T, Krutzke L Tags: Angew Chem Int Ed Engl Source Type: research

Monolayer Two-dimensional Molecular Crystals for Ultrasensitive OFET-based Chemical Sensor.
Abstract The sensitivity of conventional thin film OFETs-based sensors is limited by the diffusion of analytes through bulk films, and remains the central challenge in sensing technology. Here, for the first time we reported an ultrasensitive (sub-ppb level) sensor exploiting n-type monolayer molecular crystals (MMCs) with porous two-dimensional structures. Thanks to monolayer crystal structure of NDI3HU-DTYM2 (NDI) and controlled formation of porous structure, a world-record detection limit of NH 3 (0.1 ppb) was achieved. Moreover, the MMC-OFETs also enabled direct detection of solid analytes of biological amine ...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Jiang L, Li H, Shi Y, Han G, Liu J, Zhang J, Li C, Liu J, Yi Y, Li T, Gao X, Di C, Huang J, Che Y, Wang D, Hu W, Liu Y Tags: Angew Chem Int Ed Engl Source Type: research

Light-harvesting nanoparticle probes for FRET-based detection of oligonucleotides with single-molecule sensitivity.
Abstract Controlling emission of bright luminescent nanoparticles by a single molecular recognition event remains an ultimate challenge in the design of ultrasensitive probes for biomolecules. It would require an efficient Förster resonance energy transfer (FRET) from the nanoparticle to a single acceptor at its surface, which is not realized to date. Here, we developed 20-nm light-harvesting nanoantenna particles, built of a tailor-made hydrophobic charged polymer poly(ethyl methacrylate-co-methacrylic acid), encapsulating ~1000 strongly coupled and highly emissive rhodamine dyes with their bulky counterion....
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Melnychuk N, Egloff S, Runser A, Reisch A, Klymchenko AS Tags: Angew Chem Int Ed Engl Source Type: research

Active and Unidirectional Acceleration of Biaryl Rotation by a Molecular Motor.
Abstract Light driven molecular motors possess immense potential as central driving units for future nanotechnology. Integration into larger molecular setups and transduction of their mechanical motions represents the current frontier of research. Here we report on an integrated molecular machine setup allowing to transmit potential energy from a motor unit unto a remote receiving entity. The setup consists of a motor unit connected covalently to a distant and sterically strongly encumbered biaryl receiver. By action of the motor unit single bond rotation of the receiver is strongly accelerated and forced to proce...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Uhl E, Mayer P, Dube H Tags: Angew Chem Int Ed Engl Source Type: research

Multicomponent Peptide Stapling as a Diversity-Driven Tool for the Development of Inhibitors of Protein-Protein Interactions.
Abstract Stapled peptides are chemical entities in-between biologics and small molecules, which have proven to be the solution to high affinity protein-protein interaction antagonism while keeping control over pharmacological performance such as stability and membrane penetration. We demonstrate that the multicomponent reaction-based stapling is an effective strategy for the development of α-helical peptides with highly potent dual antagonistic action of MDM2 and MDMX binding p53. Such a potent inhibitory activity of p53-MDM2/X interactions was assessed by fluorescence polarization, microscale thermophoresis...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Doemling A, Ricardo M, Ali A, Plewka J, Surmiak E, Labuzek B, Neochoritis C, Atmaj J, Skalniak L, Zhang R, Holak T, Groves M, Rivera D Tags: Angew Chem Int Ed Engl Source Type: research

MOF Crystal Engineering Design for Cu-[O]-Ce Species in Cu-CeO2 Photoactivated Catalyst.
Abstract Fully utilizing solar energy for catalysis requires integration of conversion mechanisms and therefore delicate design of catalyst structures and active species. Here, a MOF crystal engineering method was developed to controllably synthesize the copper-ceria catalyst with well-dispersed photoactive Cu-[O]-Ce species. Using preferential CO oxidation as a model reaction, the catalyst showed remarkably efficient and stable photoactivated catalysis, which found practical application in feed gas treatment for fuel cell gas supply. The coexistence of photochemistry and thermochemistry effects contributes to the...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Wang F, Tian J, Li M, Li W, Chen L, Liu X, Li J, Muhetaer A, Li Q, Wang Y, Gu L, Ma D, Xu D Tags: Angew Chem Int Ed Engl Source Type: research

Designing 0D/2D S-scheme Heterojunction over Polymeric Carbon Nitride for Visible-Light Photocatalytic Inactivation of Bacteria.
Abstract Constructing heterojunctions between two semiconductors with matched band structure is one of the most effective strategies to acquire high-efficiency photocatalysts. S-scheme heterojunction system, as an innovative photocatalytic system, has shown great potential in facilitating separation and transfer of photogenerated carriers, as well as acquiring strong photoredox ability. Herein, a 0D/2D S-scheme heterojunction material involving CeO 2 quantum dots and polymeric carbon nitride (CeO 2 /PCN) is designed and constructed via in-situ wet chemistry with subsequent heat treatment. This S-scheme heterojunct...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Xia P, Cao S, Zhu B, Liu M, Shi M, Yu J, Zhang Y Tags: Angew Chem Int Ed Engl Source Type: research

9,9-Dimethylxanthene Derivatives: New RTP Family Member and the Adjustable Performance through Substituent Effect.
Abstract Room temperature phosphorescence (RTP) emitters with ultralong lifetime are emerging as attractive concern due to the potential applications in bioimaging, security and other areas. But their development is limited by ambiguous mechanism and unregulated RTP property with molecular design. In this text, with the incorporation of different substituents to 9,9-dimethylxanthene core, RTP lifetime of resultant compounds can increase from 52 to 601 ms by the tunable intermolecular interactions and molecular configurations. The most persistent RTP of compound XCO-PiCl is mainly due to the little steric hindrance...
Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Li Z Tags: Angew Chem Int Ed Engl Source Type: research

Unprecedented Sequence Control and Sequence-Driven Properties in A Series of AB-Alternating Copolymers Consisting Solely of Acrylamide Units.
Abstract In this article, we report a method to synthesize a series of alternating copolymers that consist exclusively of acrylamide units. Crucial to realizing the unprecedented polymer synthesis is the design of a divinyl monomer that contains acrylate and acrylamide moieties connected via two activated ester bonds. This elaborate design, which is based on the reactivity ratio of the embedded vinyl groups, allows a "selective" cyclopolymerization, wherein the intramolecular and intermolecular propagation are repeated alternately under dilute conditions. The addition of an amine to the resulting cyclopo...
Source: Angewandte Chemie - January 14, 2020 Category: Chemistry Authors: Ouchi M, Kametani Y, Sawamoto M, Tournilhac FG Tags: Angew Chem Int Ed Engl Source Type: research

Electron transfer in the Cs Ì{Mn4Fe4} cubic switch: a soluble molecular model of the MnFe Prussian Blue Analogs (PBAs).
Electron transfer in the CsÌ{Mn4Fe4} cubic switch: a soluble molecular model of the MnFe Prussian Blue Analogs (PBAs). Angew Chem Int Ed Engl. 2020 Jan 14;: Authors: Jimenez JR, Glatz J, Benchohra A, Gontard G, Chamoreau LM, Meunier JF, Bousseksou A, Lescouezec R Abstract A mixed valence {Mn II 3 Mn III Fe II 2 Fe III 2 } cyanide-bridged molecular cube hosting a caesium cation, CsÌ{Mn 4 Fe 4 }, was synthesized and structurally characterized by X-ray diffraction. Cyclic-voltammetry measurements show that its electronic state can be switched between five different redox states, which resul...
Source: Angewandte Chemie - January 14, 2020 Category: Chemistry Authors: Jimenez JR, Glatz J, Benchohra A, Gontard G, Chamoreau LM, Meunier JF, Bousseksou A, Lescouezec R Tags: Angew Chem Int Ed Engl Source Type: research

Highly Potent Dual BET/HDAC Inhibitors for the Efficient Treatment of Pancreatic Cancer.
Abstract As one of the most aggressive and lethal human malignancies with extremely poor prognosis, there is an urgent demand of more effective therapy for the treatment of pancreatic cancer. Herein we wish to report a new, effective therapeutic strategy that small molecule inhibitors simultaneously targeting bromodomain and extra-terminal (BET) and histone deacetylase (HDAC) are rationally designed as promising therapeutic agents for pancreatic cancer. A highly potent dual inhibitor ( 13a ) is identified to possess excellent and balanced activities against BRD4 BD1 (IC 50 = 11 nM) and HDAC1 (IC 50 = 21 nM). Notab...
Source: Angewandte Chemie - January 14, 2020 Category: Chemistry Authors: Wang W, He S, Dong G, Li Y, Wu S, Sheng C Tags: Angew Chem Int Ed Engl Source Type: research

Crosstalk-Free Patterning of Cooperative-Thermoresponse Images by the Synergy of the AIEgen with the Liquid Crystal.
Abstract Patterning multiple images within a single element without crosstalk can significantly increase the information capacity and security. Yet, it still remains challenging to enable the response capability in each image. Herein, we successfully demonstrate the patterning of crosstalk-free yet cooperative-thermoresponse images (e.g., holographic and fluorescent images) by deliberately designing a liquid crystal (LC)/AIEgen system with a unique synergy. The AIEgen's fluorescence intensity is found to be well controlled by the LC while the LC's phase transition is in turn promoted by the AIEgen. The fluorescent...
Source: Angewandte Chemie - January 14, 2020 Category: Chemistry Authors: Zhao Y, Zhao X, Li MD, Li Z, Peng H, Xie X Tags: Angew Chem Int Ed Engl Source Type: research

Reversible pH responsive coacervate formation in lipid vesicles activates dormant enzymatic reactions.
In conclusion, this work establishes a tuneable, pH responsive, enzymatically active multi-compartment synthetic cell. The system is readily transferred into microfluidics, making it a robust model for addressing general questions in biology such as the role of phase separation and its effect on enzymatic reactions using a bottom-up synthetic biology approach. PMID: 31943629 [PubMed - as supplied by publisher] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 14, 2020 Category: Chemistry Authors: Love C, Steinkühler J, Gonzales DT, Yandrapalli N, Robinson T, Dimova R, Tang TD Tags: Angew Chem Int Ed Engl Source Type: research

Formation and Fate of Formaldehyde in the Methanol-To-Hydrocarbons Reaction: An In Situ Synchrotron Radiation Photoionization Mass Spectrometry Study.
Abstract Formaldehyde (HCHO) has been confirmed as an active intermediate in methanol-to-hydrocarbons (MTH) reaction, which is critical for interpreting the mechanisms of coke formation. In this work, HCHO was unambiguously detected and quantified for the first time during the MTH process over HSAPO-34 and HZSM-5 by in situ synchrotron radiation photoionization mass spectrometry (SR-PIMS). Compared with conventional methods, excellent time-resolved profiles (5 s intervals) of SR-PIMS could be obtained to study the formation and fate of HCHO and other products in the induction period, steady-state reaction period a...
Source: Angewandte Chemie - January 14, 2020 Category: Chemistry Authors: Wen W, Yu S, Zhou C, Ma H, Zhou Z, Cao C, Yang J, Xu M, Qi F, Zhang G, Pan Y Tags: Angew Chem Int Ed Engl Source Type: research

NHC-Ni(II)-Catalyzed [3+2] Cross-Dimerization of Unactivated Olefin and Methylenecyclopropane.
Abstract Cross-dimerization of methylenecyclopropane 1 (or 1¢) and unactivated alkene 2 over a typical hydroalkenylation reactivity was observed for the first time by using a new [NHC-Ni(allyl)]BArF catalyst. Results showed that the C-C cleavage of 1 (or 1') did not involve a Ni(0) oxidative addition, which is crucial in former systems. This emerges a complementary method for attaining highly chemo- and regio-selective synthesis of methylenecyclopentane 3 and broad scope. An efficient NHC-Ni(II) catalyzed rearrangement of 1 (or 1') was found liable for convergent synthesis of 3 in the presence of 2. PMID...
Source: Angewandte Chemie - January 14, 2020 Category: Chemistry Authors: Ho CY, Huang JQ Tags: Angew Chem Int Ed Engl Source Type: research