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1. Small Molecule Activation with Intramolecular “Inverse” Frustrated Lewis Pairs

   https://doi.org/10.1002/chem.202005143  

   Manankandayalage, Chamila ; Unruh, Daniel K. ; Krempner, Clemens ( March 2021 , Chemistry – A European Journal)

   The intramolecular “inverse” frustrated Lewis pairs (FLPs) of general formula 1‐BR₂‐2‐[(Me₂N)₂C=N]‐C₆H₄(3–6) [BR₂=BMes₂(3), BC₁₂H₈, (4), BBN (5), BBNO (6)] were synthesized and structurally characterized by multinuclear NMR spectroscopy and X‐ray analysis. These novel types of pre‐organized FLPs, featuring strongly basic guanidino units rigidly linked to weakly Lewis acidic boryl moieties via anortho‐phenylene linker, are capable of activating H−H, C−H, N−H, O−H, Si−H, B−H and C=O bonds.4and5deprotonated terminal alkynes and acetylene to form the zwitterionic borates 1‐(RC≡C‐BR₂)‐2‐[(Me₂N)₂C=NH]‐C₆H₄(R=Ph, H) and reacted with ammonia, BnNH₂and pyrrolidine, to generate the FLP adducts 1‐(R₂HN→BR₂)‐2‐[(Me₂N)₂C=NH]‐C₆H₄, where the N‐H functionality is activated by intramolecular H‐bond interactions. In addition,5was found to rapidly add across the double bond of H₂CO, PhCHO and PhNCO to form cyclic zwitterionic guanidinium borates in excellent yields. Likewise,5is capable of cleaving H₂, HBPin and PhSiH₃to form various amino boranes. Collectively, the results demonstrate that these new types of intramolecular FLPs featuring weakly Lewis acidic boryl and strongly basic guanidino moieties are as potent as conventional intramolecular FLPs with strongly Lewis acidic units in activating small molecules.

    

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2. (Digital Presentation) Ultrathin Stabilized Zn Metal Anode for Highly Reversible Aqueous Zn-Ion Batteries

   https://doi.org/10.1149/MA2022-024439mtgabs  

   Zhang, Yuxuan ; Song, Han Wook ; Lee, Sunghwan ( October 2022 , ECS Meeting Abstracts)

   Ever-increasing demands for energy, particularly being environmentally friendly have promoted the transition from fossil fuels to renewable energy.¹Lithium-ion batteries (LIBs), arguably the most well-studied energy storage system, have dominated the energy market since their advent in the 1990s.²However, challenging issues regarding safety, supply of lithium, and high price of lithium resources limit the further advancement of LIBs for large-scale energy storage applications.³Therefore, attention is being concentrated on an alternative electrochemical energy storage device that features high safety, low cost, and long cycle life. Rechargeable aqueous zinc-ion batteries (ZIBs) is considered one of the most promising alternative energy storage systems due to the high theoretical energy and power densities where the multiple electrons (Zn²⁺) . In addition, aqueous ZIBs are safer due to non-flammable electrolyte (e.g., typically aqueous solution) and can be manufactured since they can be assembled in ambient air conditions.⁴As an essential component in aqueous Zn-based batteries, the Zn metal anode generally suffers from the growth of dendrites, which would affect battery performance in several ways. Second, the led by the loose structure of Zn dendrite may reduce the coulombic efficiency and shorten the battery lifespan.⁵

   Several approaches were suggested to improve the electrochemical stability of ZIBs, such as implementing an interfacial buffer layer that separates the active Zn from the bulk electrolyte.⁶However, the and thick thickness of the conventional Zn metal foils remain a critical challenge in this field, which may diminish the energy density of the battery drastically. According to a theretical calculation, the thickness of a Zn metal anode with an areal capacity of 1 mAh cm^-2is about 1.7 μm. However, existing extrusion-based fabrication technologies are not capable of downscaling the thickness Zn metal foils below 20 μm.

   Herein, we demonstrate a thickness controllable coating approach to fabricate an ultrathin Zn metal anode as well as a thin dielectric oxide separator. First, a 1.7 μm Zn layer was uniformly thermally evaporated onto a Cu foil. Then, Al₂O₃, the separator was deposited through sputtering on the Zn layer to a thickness of 10 nm. The inert and high hardness Al₂O₃layer is expected to lower the polarization and restrain the growth of Zn dendrites. Atomic force microscopy was employed to evaluate the roughness of the surface of the deposited Zn and Al₂O₃/Zn anode structures. Long-term cycling stability was gauged under the symmetrical cells at 0.5 mA cm^-2for 1 mAh cm^-2. Then the fabricated Zn anode was paired with MnO₂as a full cell for further electrochemical performance testing. To investigate the evolution of the interface between the Zn anode and the electrolyte, a home-developed in-situ optical observation battery cage was employed to record and compare the process of Zn deposition on the anodes of the Al₂O₃/Zn (demonstrated in this study) and the procured thick Zn anode. The surface morphology of the two Zn anodes after circulation was characterized and compared through scanning electron microscopy. The tunable ultrathin Zn metal anode with enhanced anode stability provides a pathway for future high-energy-density Zn-ion batteries.

   Obama, B., The irreversible momentum of clean energy.Science2017,355(6321), 126-129.

   Goodenough, J. B.; Park, K. S., The Li-ion rechargeable battery: a perspective.J Am Chem Soc2013,135(4), 1167-76.

   Li, C.; Xie, X.; Liang, S.; Zhou, J., Issues and Future Perspective on Zinc Metal Anode for Rechargeable Aqueous Zinc‐ion Batteries.Energy & Environmental Materials2020,3(2), 146-159.

   Jia, H.; Wang, Z.; Tawiah, B.; Wang, Y.; Chan, C.-Y.; Fei, B.; Pan, F., Recent advances in zinc anodes for high-performance aqueous Zn-ion batteries.Nano Energy2020,70.

   Yang, J.; Yin, B.; Sun, Y.; Pan, H.; Sun, W.; Jia, B.; Zhang, S.; Ma, T., Zinc Anode for Mild Aqueous Zinc-Ion Batteries: Challenges, Strategies, and Perspectives.Nanomicro Lett2022,14(1), 42.

   Yang, Q.; Li, Q.; Liu, Z.; Wang, D.; Guo, Y.; Li, X.; Tang, Y.; Li, H.; Dong, B.; Zhi, C., Dendrites in Zn-Based Batteries.Adv Mater2020,32(48), e2001854.

   Acknowledgment

   This work was partially supported by the U.S. National Science Foundation (NSF) Award No. ECCS-1931088. S.L. and H.W.S. acknowledge the support from the Improvement of Measurement Standards and Technology for Mechanical Metrology (Grant No. 22011044) by KRISS.

   Figure 1

    

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3. A Nontemplated Route to Macrocyclic Dibridgehead Diphosphorus Compounds: Crystallographic Characterization of a “Crossed‐Chain” Variant of in / out Stereoisomers

   https://doi.org/10.1002/asia.201800739  

   Kharel, Sugam ; Jia, Tiezheng ; Bhuvanesh, Nattamai ; Reibenspies, Joseph H. ; Blümel, Janet ; Gladysz, John A. ( August 2018 , Chemistry – An Asian Journal)

   Reactions of (O=)PH(OCH₂CH₃)₂and BrMg(CH₂)_mCH=CH₂(4.9–3.2 equiv;m=4 (a), 5 (b), 6 (c)) give the dialkylphosphine oxides (O=)PH[(CH₂)_mCH=CH₂]₂(2 a–c; 77–81 % after workup), which are treated with NaH and then α,ω‐dibromides Br(CH₂)_nBr (0.49–0.32 equiv;n=8 (a′), 10 (b′), 12 (c′), 14 (d′)) to yield the bis(trialkylphosphine oxides) [H₂C=CH(CH₂)_m]₂P(=O)(CH₂)_n(O=)P[(CH₂)_mCH=CH₂]₂(3 ab′,3 bc′,3 cd′,3 ca′; 79–84 %). Reactions of3 bc′and3 ca′with Grubbs’ first‐generation catalyst and then H₂/PtO₂afford the dibridgehead diphosphine dioxides(4 bc′,4 ca′; 14–19 %,n′=2m+2);³¹P NMR spectra show two stereoisomeric species (ca. 70:30). Crystal structures of two isomers of the latter are obtained,out,out‐4 ca′and a conformer ofin,out‐4 ca′that features crossed chains, such that the (O=)P vectors appearout,out. Whereas4 bc′resists crystallization, a byproduct derived from an alternative metathesis mode, (CH₂)₁₂P(=O)(CH₂)₁₂(O=)P(CH₂)₁₂, as well as3 ab′and3 bc′, are structurally characterized. The efficiencies of other routes to dibridgehead diphosphorus compounds are compared.

    

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4. From an Isolable Bismolyl Anion to an Yttrium–Bismolyl Complex with μ‐Bridging Bismuth(I) Centers and Polar Covalent Y‐Bi Bonds

   https://doi.org/10.1002/chem.202302687  

   Pugliese, Elizabeth R. ; Benner, Florian ; Demir, Selvan ( October 2023 , Chemistry – A European Journal)

   The synthesis and first structural characterization of the [K(18‐crown‐6)] bismolyl Bi^tet(C₄Me₄Bi) contact ion pair (1) is presented. Notably, according to Natural Resonance Theory calculations, the Bi^tetanion of1features two types of leading mesomeric structures with localized anionic charge and two lone pairs of electrons at the Bi^Icenter, as well as delocalized anionic charge in the π‐conjugated C₄Bi ring. The lone pairs at Bi enable a unique bridging coordination mode of the bismolyl ligand, as shown for the first rare earth metal bismolyl complex (Cp^tet₂Y)₂(μ‐η¹‐Bi^tet)₂(2). The latter results from the salt metathesis reaction of KBi^tetwith Cp^tet₂Y(BPh₄) (Cp^tet=C₅Me₄H). The Y‐Bi bonding interaction in2of 16.6 % covalency at yttrium is remarkably large.

    

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5. Development, Screening, and Validation of Camelid‐Derived Nanobodies for Neuroscience Research

   https://doi.org/10.1002/cpns.107  

   Gavira‐O'Neill, Clara E. ; Dong, Jie‐Xian ; Trimmer, James S. ( November 2020 , Current Protocols in Neuroscience)

   Nanobodies (nAbs) are recombinant antigen‐binding variable domain fragments obtained from heavy‐chain‐only immunoglobulins. Among mammals, these are unique to camelids (camels, llamas, alpacas, etc.). Nanobodies are of great use in biomedical research due to their efficient folding and stability under a variety of conditions, as well as their small size. The latter characteristic is particularly important for nAbs used as immunolabeling reagents, since this can improve penetration of cell and tissue samples compared to conventional antibodies, and also reduce the gap distance between signal and target, thereby improving imaging resolution. In addition, their recombinant nature allows for unambiguous definition and permanent archiving in the form of DNA sequence, enhanced distribution in the form of sequences or plasmids, and easy and inexpensive production using well‐established bacterial expression systems, such as the IPTG induction method described here. This article will review the basic workflow and process for developing, screening, and validating novel nAbs against neuronal target proteins. The protocols described make use of the most common nAb development method, wherein an immune repertoire from an immunized llama is screened via phage display technology. Selected nAbs can then be taken through validation assays for use as immunolabels or as intrabodies in neurons. © 2020 Wiley Periodicals LLC.

   This article was corrected on 26 June 2021. See the end of the full text for details.

   Basic Protocol 1: Total RNA isolation from camelid leukocytes

   Basic Protocol 2: First‐strand cDNA synthesis; V_HH and V_Hrepertoire PCR

   Basic Protocol 3: Preparation of the phage display library

   Basic Protocol 4: Panning of the phage display library

   Basic Protocol 5: Small‐scale nAb expression

   Basic Protocol 6: Sequence analysis of selected nAb clones

   Basic Protocol 7: Nanobody validation as immunolabels

   Basic Protocol 8: Generation of nAb‐pEGFP mammalian expression constructs

   Basic Protocol 9: Nanobody validation as intrabodies

   Support Protocol 1: ELISA for llama serum testing, phage titer, and screening of selected clones

   Support Protocol 2: Amplification of helper phage stock

   Support Protocol 3: nAb expression in amber suppressorE. colibacterial strains

    

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