| 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. |
- 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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| 3. |
- Shatskiy, Andrey, et al.
(författare)
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Controlling Radical Relay Processes with Visible Light
- 2021
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Ingår i: Chem. - : Cell Press. - 2451-9308 .- 2451-9294. ; 7:2, s. 283-285
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Harnessing free radical intermediates for selective functionalization of organic compounds has been widely demonstrated under photocatalytic conditions requiring a distinct photocatalyst. In this issue of Chem, Seo, Chang, and co-workers demonstrate an alternative photocatalyst- free light-mediated approach that allows efficient amidation of aldehydes via N-centered radical intermediate.
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| 4. |
- Yang, Shun, et al.
(författare)
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Reversibly modulating a conformation-adaptive fluorophore in [2]catenane
- 2021
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Ingår i: Chem. - : Elsevier BV. - 2451-9308 .- 2451-9294. ; 7:6, s. 1544-1556
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Tidskriftsartikel (refereegranskat)abstract
- Tuning molecular emission by chemicalmeans has long been a fundamental topic, because the emerging methodologies and mechanisms of this topic usually bring a lot of opportunities in many multi-disciplinary applications. Here, we demonstrate the reversible switching of a conformation-adaptive fluorophore, 9,14-diphenyl-9,14-dihydrodibenzo[ a,c]phenazine (DPAC), by incorporating this fluorescent unit into a mechanically interlocked [2]catenane. Taking advantage of the mechanical bond of [2]catenane, the conformational freedom of the DPAC-macrocycle can be modulated by the co-conformational state of the [2]catenane, thus enabling the reversible switching of the fluorescent properties of DPAC. Owing to the mechanically interlocked structure, this fluorescent molecular system can be switched in a dual-mode (wavelength or intensity), visually recognizable, and highly reversible manner. This work provides a distinctmechanism of switchingmolecular emission by modulating conformation-adaptive fluorescent systems in mechanically interlocked structures.
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