| 1. |
- Amombo Noa, Francoise Mystere, 1988, et al.
(författare)
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A unified topology approach to dot-, rod-, and sheet-MOFs
- 2021
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Ingår i: Chem. - : Elsevier BV. - 2451-9294 .- 2451-9308. ; 7:9, s. 2491-2512
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Tidskriftsartikel (refereegranskat)abstract
- Metal-organic frameworks made from multi-metal-ion units in the shape of clusters and rods (termed dot-MOFs and rod-MOFs) are well known. Here, we introduce MOFs with multi-metallic units in the form of sheets-sheet-MOFs. We show exemplars of all three types of units based on structures containing Y3+, Ce3+, or Gd3+ linked by benzene1,2,4,5-tetracarboxylate to give crystals of a dot-MOF in H2NMe2[Y(b-tec)(H2O)] CTH-14, a sheet-MOF in [Ce-3(btec)(Hbtec)(OAc)(HCO2)] CTH-15, and a rod-MOF in 4,4'-azopyridinium[Gd-2(btec)(2)] CTH-16. Cyclic voltammetry shows that CTH-15 stabilizes Ce(IV). Given the fact that sheet-MOFs represent an intellectual advance in the evolution of MOFs, a unified approach is proposed for the topological classification of dot-, rod-, and sheet-MOFs. It is suggested that the stability ofMOFs follow in the trend dot < rod < sheet. For CTH-14-16, the sheet- and the rod-MOF have higher thermal stability. We suggest sheet-MOFs as an additional strategy for making robust MOFs.
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| 2. |
- Beeren, Sophie R., et al.
(författare)
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The mechanical bond in biological systems
- 2023
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Ingår i: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 9:6, s. 1378-1412
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Forskningsöversikt (refereegranskat)abstract
- The field of mechanically interlocked molecules (MIMs) has advanced rapidly in recent years, with much work focused on their use in materials, sensing, and catalysis. However, the use of MIMs in biology and biomedicine has been limited, despite the identifica-tion of naturally occurring MIMs in DNA and proteins and the poten-tial advantages of the mechanical bond in fields such as nanomedi-cine and tissue engineering. Difficulties in the synthesis of MIMs, along with their limited solubility and stability in biological media, have until recently impeded their wider application in biology. Contemporary advances have, however, enabled a broader integra-tion of the mechanical bond in biology; the mechanical interlocking endows these systems with unique functional advantages. Herein, we summarize recent advances in the application of small-molecule, biologically derived, and polymeric MIMs in biology, highlighting synergies ripe for future exploration.
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| 3. |
- Benesperi, Iacopo, et al.
(författare)
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Dynamic dimer copper coordination redox shuttles
- 2022
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Ingår i: Chem. - : Elsevier. - 2451-9308 .- 2451-9294. ; 8:2, s. 439-449
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Tidskriftsartikel (refereegranskat)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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| 4. |
- Bermejo-López, Aitor, 1989-
(författare)
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Don't become your own resting state
- 2022
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Ingår i: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 8:12, s. 3154-3155
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)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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| 5. |
- Bermejo-López, Aitor, 1989-, et al.
(författare)
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Selective and quantitative functionalization of unprotected α-amino acids using a recyclable homogeneous catalyst
- 2022
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Ingår i: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 8:12, s. 3302-3323
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Tidskriftsartikel (refereegranskat)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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| 6. |
- Breitwieser, Kevin, et al.
(författare)
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Dawn of a new era? A base-metal single-atom catalyst for organic fine chemical synthesis
- 2024
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Ingår i: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 10:6, s. 1633-1635
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Tidskriftsartikel (refereegranskat)abstract
- Single-atom catalysts (SACs) hold the potential to combine the benefits of both heterogeneous and homogeneous catalysis. In this issue of Chem, Beller and co-workers demonstrate the selective insertion of transient copper carbenes into diverse X‒H (X = C, N, O, S) bonds with excellent functional-group tolerance by using a porous Al2O3-supported SAC.
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| 7. |
- Chen, Xuehan, et al.
(författare)
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Perspective Phosphine oxide additives for perovskite diodes and solar cells
- 2023
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Ingår i: Chem. - : CELL PRESS. - 2451-9308 .- 2451-9294. ; 9:3, s. 562-575
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Forskningsöversikt (refereegranskat)abstract
- Lead halide perovskites have been considered promising semicon-ducting materials for next-generation optoelectronic devices due to their solution processability and excellent optoelectronic proper-ties. Device performance of perovskite light-emitting diodes (PeLEDs) and perovskite solar cells (PSCs) has been rapidly devel-oped during the past decade. Very recently, organic molecules containing phosphine oxide groups have emerged as promising ad-ditives and passivators to improve the device performance and sta-bility of both PeLEDs and PSCs. In this perspective, we summarize recent progress in the development of new phosphine-oxide-based additives for PeLEDs and PSCs. The passivation mechanism, molecule design principle, and structure-property relationship of phosphine oxide molecules for PeLEDs and PSCs are systematically discussed and analyzed. Finally, we provide an outlook on the mo-lecular design of novel phosphine oxide compounds for efficient and stable PeLEDs and PSCs in the future.
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| 8. |
- Davison, Nathan, et al.
(författare)
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A room-temperature-stable electride and its reactivity : Reductive benzene/pyridine couplings and solvent-free Birch reductions
- 2023
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Ingår i: Chem. - : Elsevier. - 2451-9308 .- 2451-9294. ; 9:3, s. 576-591
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we report the synthesis of a room-temperature-stable electride (RoSE) reagent, namely K+(LiHMDS)e− (1) (HMDS: 1,1,1,3,3,3-hexamethyldisilazide), from accessible starting materials (potassium metal and LiHMDS) via mechanochemical ball milling at 20 mmol scale. Despite its amorphous nature, the presence of anionic electrons in 1, key diagnostic criteria for an electride, was confirmed by both experimental and computational studies. Therefore, by definition, 1 is an electride. Utilizing its anionic electrons, electride reagent 1 exhibited a versatile reactivity profile that includes (1) mediation of C–H activation and C–C coupling of benzene and pyridine and (2) mediation of solvent-free Birch reduction. This work proves the concept of facile mechanochemical synthesis of a room-temperature-stable electride, and it introduces electride 1 to the synthetic chemistry community as a versatile reagent.
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| 9. |
- Finkelstein-Shapiro, Daniel, et al.
(författare)
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Understanding radiative transitions and relaxation pathways in plexcitons
- 2021
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Ingår i: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 7:4, s. 1092-1107
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Tidskriftsartikel (refereegranskat)abstract
- Molecular aggregates on plasmonic nanoparticles have emerged as attractive systems for the studies of polaritonic light-matter states, called plexcitons. Such systems are tunable, scalable, easy to synthesize, and offer sub-wavelength confinement, all while giving access to the ultrastrong light-matter coupling regime, promising a plethora of applications. However, the complexity of these materials prevented the understanding of their excitation and relaxation phenomena. Here, we follow the relaxation pathways in plexcitons and conclude that while the metal destroys the optical coherence, the molecular aggregate coupled to surface processes significantly contributes to the energy dissipation. We use two-dimensional electronic spectroscopy with theoretical modeling to assign the different relaxation processes to either molecules or metal nanoparticle. We show that the dynamics beyond a few femtoseconds has to be considered in the language of hot electron distributions instead of the accepted lower and upper polariton branches and establish the framework for further understanding.
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| 10. |
- Hammarström, Leif
(författare)
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Catalyst : Chemistry's Role in Providing Clean and Affordable Energy for All
- 2016
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Ingår i: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 1:4, s. 515-518
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Tidskriftsartikel (refereegranskat)abstract
- Leif Hammarstrom is a professor of chemical physics at Uppsala University, Sweden. He is one of the leaders of the Swedish Consortium for Artificial Photosynthesis, founded in the mid-1990s. He is chair of the Swedish Solar Energy Platform and represents Uppsala University as a core member of the Solar Fuels Institute.
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