| 1. |
- Benesperi, Iacopo, et al.
(author)
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Dynamic dimer copper coordination redox shuttles
- 2022
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In: Chem. - : Elsevier. - 2451-9308 .- 2451-9294. ; 8:2, s. 439-449
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Journal article (peer-reviewed)abstract
- Summary Conventional redox mediators based on metal coordination complexes undergo electron transfer through the change in oxidation state of the metal center. However, electron transfer kinetics are offset toward preferred oxidation states when preorganized ligands constrain the reorganization of the coordination sphere. In contrast, we report here on dimeric copper(II/I) redox couples, wherein the extent of oxidation/reduction of two metal centers dictates the dynamic formation of dimer and monomer complexes: the dimeric (Cu(I))2 transitions to monomers of Cu(II). The bis(thiazole/pyrrole)-bipyridine tetradentate ligands stabilize both oxidation states of the unique redox systems. The dynamic dimer redox mediators offer a viable two-electron redox mechanism to develop efficient hybrid solar cells through inhibited recombination and rapid charge transport. Density functional theory calculations reveal inner reorganization energies for single-electron transfer as low as 0.27 eV, marking the dimeric complexes superior redox systems over single complexes as liquid and potentially solid-state electrolytes.
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| 2. |
- Bermejo-López, Aitor, 1989-
(author)
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Don't become your own resting state
- 2022
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In: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 8:12, s. 3154-3155
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Journal article (other academic/artistic)abstract
- Dr. Aitor Bermejo López graduated with a degree in chemistry from the Universidad Autónoma de Madrid. He completed his master’s studies and subsequently obtained a doctoral degree in organic chemistry from Stockholm University with Prof. Belén Martín-Matute. He gained expertise in organometallic catalysis while focusing on the development of new transformations and on the study of their mechanisms. He defended his doctoral thesis recently this year and is eager to see what the future has in store and to grow as a scientist.
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| 3. |
- Bermejo-López, Aitor, 1989-, et al.
(author)
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Selective and quantitative functionalization of unprotected α-amino acids using a recyclable homogeneous catalyst
- 2022
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In: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 8:12, s. 3302-3323
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Journal article (peer-reviewed)abstract
- A new Ir(III)-NHC catalyst is reported that shows remarkable activity in the N-alkylation of unprotected amino acids. The catalytic system gives excellent selectivity toward monoalkylated α-amino acids and a high degree of retention of stereochemistry. A wide range of unprotected nonnatural amino acids have been prepared. These compounds represent an array of building blocks that could be used for the direct synthesis of peptidomimetics. The synthesis of amino-acid-based surfactants is also reported. This catalytic method gives the amino acid products in quantitative yield; hence, tedious purifications by derivatization are therefore avoided. Furthermore, although the catalyst is a homogeneous metal complex, it can be recycled and reused for several runs. This also contributes to the efficiency and sustainability of the method.
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| 4. |
- Linde, Erika, et al.
(author)
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Diarylation of N- and O-nucleophiles through a metal-free cascade reaction
- 2022
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In: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 8:3, s. 850-865
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Journal article (peer-reviewed)abstract
- The arylation of heteroatom nucleophiles is a central strategy to reach diarylated compounds that are key building blocks in agrochemicals, materials, and pharmaceuticals. Nucleophilic aromatic substitution is a classical tool for such arylations, and recent developments in hypervalent iodine-mediated arylations allow a wider scope of products. Herein, we combine the benefits of these strategies to enable an efficient and transition-metal-free difunctionalization of N-and O-nucleophiles with two structurally different aryl groups and to provide di-and triarylamines and diaryl ethers in one single step (>100 examples). The core of this strategy is the unique reactivity discovered with specifically designed fluorinated diaryliodonium salts, which unveils novel reaction pathways in hypervalent iodine chemistry. The methodology is suitable for diarylation of aliphatic amines, anilines, ammonia, and even water. It tolerates a wide variety of functional and protecting groups, with the retained iodine substituent easily accessible for derivatization of the products.
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| 5. |
- Shatskiy, Andrey, et al.
(author)
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Chemodivergent difunctionalization of alkenes through base-controlled radical relay
- 2022
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In: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 8:1, s. 12-14
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Journal article (peer-reviewed)abstract
- Establishing chemodivergent synthetic strategies remains a daunting task in the realm of free-radical reaction manifolds. In the December issue of Chem, Glorius and co-workers resolve this challenge for selective difunctionalization of aliphatic alkenes. In the disclosed light-promoted radical relay process, switchable trifluoromethylation/alkylation or trifluoromethylation/sulfonylation of alkenes is achieved.
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| 6. |
- Yang, Yizhou, 1992, et al.
(author)
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Detachable all-carbon-linked 3D covalent organic framework films for semiconductor/COF heterojunctions by continuous flow synthesis
- 2022
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In: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 8:8, s. 2217-2227
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Journal article (peer-reviewed)abstract
- New synthetic strategies are ceaselessly being explored to fabricate covalent organic frameworks (COFs) as continuous materials with controlled morphology. However, making substrate detachable thin layers of 3D COFs, which would allow for film-based applications, has turned out to be particularly difficult. Here, we developed a substrate-catalyzed synthesis in a continuous flow method that successfully realized the fabrication of crystalline detachable all-carbon-linked 3D SBFdiyne-COF films. The key element in the method is a highly controlled interfacial reaction between the Cu substrate and a base flowing over the substrate. Benefiting from the detachability and high quality of the fabricated film, an organic semiconductor/COF heterojunction was constructed, showing high current rectification performance of 104 under forward/reverse bias.
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| 7. |
- Yuan, Fanglong, et al.
(author)
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Monolayer 2D polymeric fullerene: A new member of the carbon material family
- 2022
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In: Chem. - : CELL PRESS. - 2451-9308 .- 2451-9294. ; 8:8, s. 2079-2081
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Journal article (other academic/artistic)abstract
- Two-dimensional (2D) carbon materials have attracted tremendous attention because of their unique properties, but their structures are currently limited to periodic networks of single carbon atoms. Recently in Nature, Zheng and co-workers demonstrate a new monolayer 2D carbon material composed of interconnected fullerene molecules.
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| 8. |
- Chien, Yu-Chuan, 1990-, et al.
(author)
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Correlations between precipitation reactions and electrochemical performance of lithium-sulfur batteries probed by operando scattering techniques
- 2022
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In: Chem. - : Elsevier. - 2451-9294. ; 8:5
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Journal article (peer-reviewed)abstract
- A comprehensive description of electrochemical processes in the positive electrode of lithium-sulfur batteries is crucial for the utilization of active material. However, the discharge mechanisms are complicated due to various reactions in multiple phases and the tortuosity of the highly porous carbon matrix. In this work, simultaneous measurements of small-angle and wide-angle scattering and cell resistance are performed on operating lithium-sulfur cells. Results indicate that precipitates grow mostly in number, not in size, and that the structure of the carbon matrix is not affected. The comparison of the small-angle and wide-angle scattering reveals the amorphous discharge products found at a low discharge rate. Further analysis demonstrates the correlation between the diffusion resistance and the compositional change of electrolyte in the mesopores at the end of discharge, which suggests that Li-ion deficiency is the limiting factor for sulfur utilization at a medium discharge rate.
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| 9. |
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