Permanent Porosity in Hydroxamate Titanium–Organic Polyhedra

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Journal of the American Chemical Society

Journal of the American Chemical Society: Latest Articles (ACS Publications)
Authors: Belén Lerma-Berlanga, Javier Castells-Gil, Carolina R. Ganivet, Neyvis Almora-Barrios, Javier González-Platas, Oscar Fabelo, Natalia M. Padial, and Carlos Martí-Gastaldo
dx.doi.org/https://doi.org/10.1021/jacs.1c09278

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Mapping the Regioisomeric Space and Visible Color Range of Purely Organic Dual Emitters with Ultralong Phosphorescence Components: From Violet to Red Towards Pure White Light

Mapping the Regioisomeric Space and Visible Color Range of Purely Organic Dual Emitters with Ultralong Phosphorescence Components: From Violet to Red Towards Pure White Light

An innovative set of twelve highly luminescent dual emitters based on benzensulfone moieties selectively attached to dibenzofurane is presented. These compounds can cover the whole visible part of the electromagnetic spectrum and even behave as single-source white light emitters. They show ultralong phosphorescent afterglow at room temperature, based on the positioning of the sulfone moieties.

Abstract

We mapped the entire visible range of the electromagnetic spectrum and achieved white light emission (CIE: 0.31, 0.34) by combining the intrinsic ns-fluorescence with ultralong ms-phosphorescence from purely organic dual emitters. We realized small molecular materials showing high photoluminescence quantum yields (ΦL) in the solid state at room temperature, achieved by active exploration of the regioisomeric substitution space. Chromophore stacking-supported stabilization of triplet excitons with assistance from enhanced intersystem crossing channels in the crystalline state played the primary role for the ultra-long phosphorescence. This strategy covers the entire visible spectrum, based on organic phosphorescent emitters with versatile regioisomeric substitution patterns, and provides a single molecular source of white light with long lifetime (up to 163.5 ms) for the phosphorescent component, and high overall photoluminescence quantum yields (up to ΦL=20 %).

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Bibhisan Roy, Iván Maisuls, Jianyu Zhang, Felix C. Niemeyer, Fabio Rizzo, Christoph Wölper, Constantin G. Daniliuc, Ben Zhong Tang, Cristian A. Strassert, Jens Voskuhl
onlinelibrary.wiley.com/doi/10.1002/anie.202111805

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Excited‐State Copper Catalysis for the Synthesis of Heterocycles

Excited-State Copper Catalysis for the Synthesis of Heterocycles

Visible-light-induced excited-state copper catalysis enables the synthesis of more than 10 distinct classes of heterocycles. The reaction tolerates a broad array of functional groups and complex molecular scaffolds, including derivatives of peptides, natural products, and marketed drugs.

Abstract

Heterocycles are one of the largest groups of organic moieties with significant medicinal, chemical, and industrial applications. Herein, we report the discovery and development of visible-light-induced, synergistic excited-state copper catalysis using a combination of Cu(IPr)I as a catalyst and rac-BINAP as a ligand, which produces more than 10 distinct classes of heterocycles. The reaction tolerates a broad array of functional groups and complex molecular scaffolds, including derivatives of peptides, natural products, and marketed drugs. Preliminary mechanistic investigation suggests in situ generations of [Cu(BINAP)2]+ and [Cu(IPr)2]+ catalysts that work cooperatively under visible-light irradiation to facilitate catalytic carbo-aroylation of unactivated alkenes, affording a wide range of useful heterocycles.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Arghya Banerjee, Satavisha Sarkar, Jagrut A. Shah, Nicoline C. Frederiks, Emmanuel A. Bazan‐Bergamino, Christopher J. Johnson, Ming‐Yu Ngai
onlinelibrary.wiley.com/doi/10.1002/anie.202113841

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Accelerated SuFEx Click Chemistry For Modular Synthesis**

Accelerated SuFEx Click Chemistry For Modular Synthesis**

We report accelerated SuFEx click chemistry utilizing a synergistic BTMG-HMDS catalytic system. The power and versatility of the reaction are showcased by the SuFEx synthesis of >100 unique molecules from diverse SuFExable hubs. Accelerated SuFEx is a next generation click reaction that improves upon existing protocols and expands the scope of accessible products.

Abstract

SuFEx click chemistry is a powerful method designed for the selective, rapid, and modular synthesis of functional molecules. Classical SuFEx reactions form stable S−O linkages upon exchange of S−F bonds with aryl silyl-ether substrates, and while near-perfect in their outcome, are sometimes disadvantaged by relatively high catalyst loadings and prolonged reaction times. We herein report the development of accelerated SuFEx click chemistry (ASCC), an improved SuFEx method for the efficient and catalytic coupling of aryl and alkyl alcohols with a range of SuFExable hubs. We demonstrate Barton’s hindered guanidine base (2-tert-butyl-1,1,3,3-tetramethylguanidine; BTMG) as a superb SuFEx catalyst that, when used in synergy with silicon additive hexamethyldisilazane (HMDS), yields stable S−O bond linkages in a single step; often within minutes. The powerful combination of BTMG and HMDS reagents allows for catalyst loadings as low as 1.0 mol % and, in congruence with click-principles, provides a scalable method that is safe, efficient, and practical for modular synthesis. ASSC expands the number of accessible SuFEx products and will find significant application in organic synthesis, medicinal chemistry, chemical biology, and materials science.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Christopher J. Smedley, Joshua A. Homer, Timothy L. Gialelis, Andrew S. Barrow, Rebecca A. Koelln, John E. Moses
onlinelibrary.wiley.com/doi/10.1002/anie.202112375

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A Modular Approach to the Antifungal Sphingofungin Family: Concise Total Synthesis of Sphingofungin A and C

A Modular Approach to the Antifungal Sphingofungin Family: Concise Total Synthesis of Sphingofungin A and C

A short and flexible total synthesis of antifungal and antiparasitic sphingofungins A–D and congeners was developed by combining a versatile decarboxylative coupling reaction and a cross metathesis protocol.

Abstract

Sphingofungins are fungal natural products known to inhibit the biosynthesis of sphingolipids which play pivotal roles in various cell functions. Here, we report a short and flexible synthetic approach towards the sphingofungin family. Key step of the synthesis was a decarboxylative cross-coupling reaction of chiral sulfinyl imines with a functionalized tartaric acid derivative, which yielded the core motif of sphingofungins carrying four consecutive stereocenters and a terminal double bond. Subsequent metathesis reaction allowed for the introduction of different side chains of choice resulting in a total of eight sphingofungins, including for the first time sphingofungin C (eight steps from commercially available protected tartaric acid with an overall yield of 6 %) and sphingofungin A (ten steps). All newly synthesized derivatives were tested for their antifungal, cell-proliferative and antiparasitic activity unraveling their structure–activity relations.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Luka Raguž, Chia‐Chi Peng, Marcel Kaiser, Helmar Görls, Christine Beemelmanns
onlinelibrary.wiley.com/doi/10.1002/anie.202112616

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Be–Be π‐Bonding and Predicted Superconductivity in MBe2 (M=Zr, Hf)

Be–Be π-Bonding and Predicted Superconductivity in MBe2 (M=Zr, Hf)

Beryllium in ZrBe2 and HfBe2 forms a honeycomb network of π bonds. Both materials are valence isoelectronic and isostructural to MgB2, and like that compound, are predicted to be superconductors. Beryllium, an s-block element, shows here that it may construct networks of low dimensionality by virtue of its ability to engage in π bonding. Until now, this property was exclusively associated with elements from the p-block.

Abstract

Beryllium, an s-block element, forms an aromatic network of delocalized Be–Be π bonds in alloys ZrBe2 and HfBe2. This gives rise to stacked [Be2]4− layers with tetravalent cations in between. The [Be2]4− sublattice is isoelectronic and isostructural to graphite, as well as the [B]−2 sublattice in MgB2, and it bears identical manifestations of π bonding in its electronic band structure. These come in the form of degeneracies at K and H in the Brillouin zone, separated in energy as the result of interlayer orbital interactions. Zr and Hf use their valence d orbitals to form bonds with the layers, leading to nearly identical band structures. Like MgB2, ZrBe2 and HfBe2 are computed to be phonon-mediated superconductors at ambient pressures, with respective critical temperatures of 11.4 K and 8.8 K. The coupling strength between phonons and free electrons is very similar, so that the difference in critical temperatures is controlled by the mass of constituent interlayer ions.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Maarten G. Goesten
onlinelibrary.wiley.com/doi/10.1002/anie.202114303

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Thermo‐Responsive Jamming of Nanoparticle Dense Suspensions towards Macroscopic Liquid–Solid Switchable Materials

Thermo-Responsive Jamming of Nanoparticle Dense Suspensions towards Macroscopic Liquid–Solid Switchable Materials

We demonstrate a thermo-responsive jamming of SPNPs dense suspensions for obtaining macroscopic smart liquid–solid switchable materials. This unique macroscopic behavior originates from the reversible disordered aggregation modulated by temperature-dependent hydrophobic interactions among the SPNPs.

Abstract

Nanoparticle aggregation for constructing functional materials has shown enormous advantages in various applications. Most efforts focused on ordered nanoparticle aggregation for specific functions but were often limited to irreversible aggregation processes due to the thermodynamic equilibrium. Herein, we report a reversible disordered aggregation of SiO2-PNIPAAm nanoparticles (SPNPs) through thermo-responsive jamming, obtaining smart liquid–solid switchable materials. The smart materials can display a switch between liquid-like state and solid-like state responding to a temperature change. This unique macroscopic behavior originates from the reversible disordered aggregation modulated by temperature-dependent hydrophobic interactions among the SPNPs. Notably, the materials at the solid-like state show anti-impact properties and can withstand the impact of a steel sphere with a speed of 328 cm s−1. We envision that this finding offers inspiration to design smart liquid–solid switchable materials for impact protection.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Mingqian Liu, Xizi Wan, Man Yang, Zhao Wang, Han Bao, Bing Dai, Huan Liu, Shutao Wang
onlinelibrary.wiley.com/doi/10.1002/anie.202114602

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High‐Efficiency and Stable Li−CO2 Battery Enabled by Carbon Nanotube/Carbon Nitride Heterostructured Photocathode

High-Efficiency and Stable Li−CO2 Battery Enabled by Carbon Nanotube/Carbon Nitride Heterostructured Photocathode

A carbon nanotube/carbon nitride heterostructured photocathode is designed to efficiently utilize photo-energy to boost sluggish CO2 reduction and evolution kinetics of the Li−CO2 battery. The resulting Li−CO2 battery achieves a record-high round-trip efficiency of 98.8 %, superior cycling stability with high efficiency retention of 86.1 % after 100 cycles and ultrahigh areal capacity of 15.77 mAh cm−2.

Abstract

Li−CO2 batteries are explored as promising power systems to alleviate environmental issues and to implement space applications. However, sluggish cathode kinetics of CO2 reduction/evolution result in low round-trip efficiency and poor cycling stability of the fabricated energy-storage devices. Herein, we design a heterostructued photocathode comprising carbon nanotube and carbon nitride to accelerate cathode reactions of a Li−CO2 battery under illumination. Benefiting from the unique defective structure of carbon nitride and favorable interfacial charge transfer, the photocathode effectively harvests ultraviolet-visible light to generate abundant photoexcited carriers and coordinates energetic photoelectrons/holes to participate in the discharge/charge reactions, leading to efficient photo-energy utilization in decreasing reaction barriers and enhancing thermodynamic reversibility of Li−CO2 battery. The resulting battery delivers a high round-trip efficiency of 98.8 % (ultralow voltage hysteresis of 0.04 V) and superior cycling stability (86.1 % efficiency retention after 100 cycles).

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Jiaxin Li, Kun Zhang, Yang Zhao, Chuang Wang, Lipeng Wang, Lie Wang, Meng Liao, Lei Ye, Ye Zhang, Yue Gao, Bingjie Wang, Huisheng Peng
onlinelibrary.wiley.com/doi/10.1002/anie.202114612

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The Chiral Target of Daptomycin Is the 2R,2′S Stereoisomer of Phosphatidylglycerol

The Chiral Target of Daptomycin Is the 2R,2′S Stereoisomer of Phosphatidylglycerol

Daptomycin (dap), an important clinical antibiotic, recognizes the absolute configuration of phosphatidylglycerol (PG), a key lipid found in bacterial membranes. The configuration at the headgroup of PG was found to be particularly important for dap–PG interactions. This is a rare example of a natural product targeting a membrane lipid through chiral recognition.

Abstract

Daptomycin (dap) is an important antibiotic that interacts with the bacterial membrane lipid phosphatidylglycerol (PG) in a calcium-dependent manner. The enantiomer of dap (ent-dap) was synthesized and was found to be 85-fold less active than dap against B. subtilis, indicating that dap interacts with a chiral target as part of its mechanism of action. Using liposomes containing enantiopure PG, we demonstrate that the binding of dap to PG, the structural transition that occurs upon dap binding to PG, and the subsequent oligomerization of dap, depends upon the configuration of PG, and that dap prefers the 1,2-diacyl-sn-glycero-3-phospho-1′-sn-glycerol stereoisomer (2R,2′S configuration). Ent-dap has a lower affinity for 2R,2′S liposomes than dap and cannot oligomerize to the same extent as dap, which accounts for why ent-dap is less active than dap. To our knowledge, this is the first example whereby the activity of an antibiotic depends upon the configuration of a lipid head group.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Ryan Moreira, Scott D. Taylor
onlinelibrary.wiley.com/doi/10.1002/anie.202114858

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Bulky Cyclometalated Ruthenium Nitrates for Challenging Z‐Selective Metathesis: Efficient One‐Step Access to α‐Oxygenated Z‐Olefins from Acrylates and Allyl Alcohols

Bulky Cyclometalated Ruthenium Nitrates for Challenging Z-Selective Metathesis: Efficient One-Step Access to α-Oxygenated Z-Olefins from Acrylates and Allyl Alcohols

A persistent challenge in olefin metathesis is the lack of widely applicable method that converts feedstock allyl alcohols and acylates to valuable α-oxygenated Z-olefins. Here, enabled by bulky cyclometalated Ru-nitrate catalysts whose syntheses were newly unlocked, Z-selective metathesis between terminal olefins could now be used to access Z-allyl alcohols, Z-alkenyl esters, and Z-alkenyl acids in high yields and >20 : 1 Z : E selectivity.

Abstract

α-Oxygenated Z-olefins are ubiquitous in biologically active molecules and serve as versatile handles for organic synthesis, but their syntheses are often tedious and less selective. Here we report the efficient Z-selective metathesis of various terminal acrylates and allyl alcohols, which enables facile and selective construction of high value-added α-oxygenated Z-olefins from readily available feedstock chemicals. These challenging metathesis transformations are enabled by novel cyclometalated Ru-carbene-nitrate complexes bearing bulky-yet-flexible side arms, whose assembly was unlocked by new organometallic syntheses.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Yan Xu, Quan Gan, Adrian E. Samkian, Jeong Hoon Ko, Robert H. Grubbs
onlinelibrary.wiley.com/doi/10.1002/anie.202113089

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Maximizing Step‐Normalized Increases in Molecular Complexity: Formal [4+2+2+2] Photoinduced Cyclization Cascade to Access Polyheterocycles Possessing Privileged Substructures

Maximizing Step-Normalized Increases in Molecular Complexity: Formal [4+2+2+2] Photoinduced Cyclization Cascade to Access Polyheterocycles Possessing Privileged Substructures

Excited state intramolecular proton transfer (ESIPT) in aromatic o-amino ketones with tethered dual unsaturated pendants, i.e. pyrrole and alkenic moieties, initiates a complexity building photoinduced cascade of an unprecedented formal [4+2+2+2] topology, resulting in the formation of four σ-bonds and setting six new stereogenic centers in a single photochemical step with up to 220 mcbit complexity increases.

Abstract

A new complexity building photoinduced cascade which amounts to an unprecedented formal [4+2+2+2] cycloaddition topology is developed to access complex nitrogen polyheterocycles. This photocascade is initiated by the excited state intramolecular proton transfer (ESIPT) in aromatic amino ketones with tethered dual unsaturated pendants, i.e. pyrrole and alkenic moieties, resulting in the formation of four σ-bonds and setting six new stereogenic centers in a single experimentally simple photochemical step with up to 220 mcbit complexity increases.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: D. Sai Reddy, Ivan M. Novitskiy, Andrei G. Kutateladze
onlinelibrary.wiley.com/doi/10.1002/anie.202112573

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Controlling Syneresis of Hydrogels Using Organic Salts

Controlling Syneresis of Hydrogels Using Organic Salts

For self-shrinkable hydrogels, syneresis can be controlled by tuning the hydrophobic microenvironment within the gel network involving co-assembly with organic salts.

Abstract

Supramolecular hydrogels can spontaneously undergo syneresis through fibre–fibre interactions and expel significant amounts of water upon aging. In this process, the hydrophobicity of fibres which regulates the 3D-rearrangement of the self-assembled structures during syneresis is important. Here, we show that we can control the hydrophobic microenvironment of gels by incorporating organic salts into the co-assembled gel fibres thereby enabling control of the macroscopic gel volume phase transition.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Santanu Panja, Bart Dietrich, Dave J. Adams
onlinelibrary.wiley.com/doi/10.1002/anie.202115021

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Optimizing Hydrogen Binding on Ru Sites with RuCo Alloy Nanosheets for Efficient Alkaline Hydrogen Evolution

Optimizing Hydrogen Binding on Ru Sites with RuCo Alloy Nanosheets for Efficient Alkaline Hydrogen Evolution

Optimizing Ru−H adsorption/desorption efficiency, via adjusting the Ru orbital in RuCo alloy-nanosheets, enables highly promoted alkaline hydrogen evolution reaction. This optimized adsorption/desorption efficiency is demonstrated by the hydrogen sensor and temperature program desorption experiments. The RuCo alloy-nanosheets possess a record low overpotential of 10 mV at 10 mA cm−2, superior to the commercial Pt/C and Ru/C.

Abstract

Ruthenium (Ru)-based catalysts, with considerable performance and desirable cost, are becoming highly interesting candidates to replace platinum (Pt) in the alkaline hydrogen evolution reaction (HER). The hydrogen binding at Ru sites (Ru−H) is an important factor limiting the HER activity. Herein, density functional theory (DFT) simulations show that the essence of Ru−H binding energy is the strong interaction between the orbital of Ru and the 1s orbital of H. The charge transfer between Ru sites and substrates (Co and Ni) causes the appropriate downward shift of the -band center of Ru, which results in a Gibbs free energy of 0.022 eV for H* in the RuCo system, much lower than the 0.133 eV in the pure Ru system. This theoretical prediction has been experimentally confirmed using RuCo alloy-nanosheets (RuCo ANSs). They were prepared via a fast co-precipitation method followed with a mild electrochemical reduction. Structure characterizations reveal that the Ru atoms are embedded into the Co substrate as isolated active sites with a planar symmetric and Z-direction asymmetric coordination structure, obtaining an optimal modulated electronic structure. Hydrogen sensor and temperature program desorption (TPD) tests demonstrate the enhanced Ru−H interactions in RuCo ANSs compared to those in pure Ru nanoparticles. As a result, the RuCo ANSs reach an ultra-low overpotential of 10 mV at 10 mA cm−2 and a Tafel slope of 20.6 mV dec−1 in 1 M KOH, outperforming that of the commercial Pt/C. This holistic work provides a new insight to promote alkaline HER by optimizing the metal-H binding energy of active sites.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Chao Cai, Kang Liu, Yuanmin Zhu, Pengcheng Li, Qiyou Wang, Bao Liu, Shanyong Chen, Huangjingwei Li, Li Zhu, Hongmei Li, Junwei Fu, Yu Chen, Evangelina Pensa, Junhua Hu, Ying‐Rui Lu, Ting‐Shan Chan, Emiliano Cortés, Min Liu
onlinelibrary.wiley.com/doi/10.1002/anie.202113664

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Unveiling the Unique Roles of Metal Coordination and Modulator in the Polymorphism Control of Metal–Organic Frameworks

Unveiling the Unique Roles of Metal Coordination and Modulator in the Polymorphism Control of Metal–Organic Frameworks

The extraordinary coordination versatility of the Th4+ cation and the unexpected bridging role of formate allows polymorphism control of thorium–organic frameworks (TOFs) with five distinct phases, wherein the highest degree of porosity and interpenetration for TOFs have been achieved. More information can be found in the Full Paper by J. Lin et al. (DOI: 10.1002/chem.202103062).

Wiley: Chemistry – A European Journal: Table of Contents
Authors: Zi‐Jian Li, Yu Ju, Zeya Zhang, Huangjie Lu, Yongxin Li, Ningjin Zhang, Xian‐Long Du, Xiaofeng Guo, Zhi‐Hui Zhang, Yuan Qian, Ming‐Yang He, Jian‐Qiang Wang, Jian Lin
chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/chem.202104274

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Heterometallic CeIV/ VV Oxo Clusters with Adjustable Catalytic Reactivities

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Journal of the American Chemical Society

Journal of the American Chemical Society: Latest Articles (ACS Publications)
Authors: Xingjie Wang, Kieran Brunson, Haomiao Xie, Ian Colliard, Megan C. Wasson, Xinyi Gong, Kaikai Ma, Yufang Wu, Florencia A. Son, Karam B. Idrees, Xuan Zhang, Justin M. Notestein, May Nyman, and Omar K. Farha
dx.doi.org/https://doi.org/10.1021/jacs.1c11208

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Creation of Exclusive Artificial Cluster Defects by Selective Metal Removal in the (Zn, Zr) Mixed-Metal UiO-66

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Journal of the American Chemical Society

Journal of the American Chemical Society: Latest Articles (ACS Publications)
Authors: Xiao Feng, Himanshu Sekhar Jena, Chidharth Krishnaraj, Daniel Arenas-Esteban, Karen Leus, Guangbo Wang, Jiamin Sun, Martina Rüscher, Janis Timoshenko, Beatriz Roldan Cuenya, Sara Bals, and Pascal Van Der Voort
dx.doi.org/https://doi.org/10.1021/jacs.1c05357

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