| 1. |
- Gerasimov, Jennifer Yevgenia, 1985-, et al.
(författare)
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Rational Materials Design for In Operando Electropolymerization of Evolvable Organic Electrochemical Transistors
- 2022
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Ingår i: Advanced Functional Materials. - : John Wiley and Sons Inc. - 1616-301X .- 1616-3028. ; 32
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Tidskriftsartikel (refereegranskat)abstract
- Organic electrochemical transistors formed by in operando electropolymerization of the semiconducting channel are increasingly becoming recognized as a simple and effective implementation of synapses in neuromorphic hardware. However, very few studies have reported the requirements that must be met to ensure that the polymer spreads along the substrate to form a functional conducting channel. The nature of the interface between the substrate and various monomer precursors of conducting polymers through molecular dynamics simulations is investigated, showing that monomer adsorption to the substrate produces an increase in the effective monomer concentration at the surface. By evaluating combinatorial couples of monomers baring various sidechains with differently functionalized substrates, it is shown that the interactions between the substrate and the monomer precursor control the lateral growth of a polymer film along an inert substrate. This effect has implications for fabricating synaptic systems on inexpensive, flexible substrates. © 2022 The Authors.
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| 2. |
- Hjort, Martin, et al.
(författare)
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In situ assembly of bioresorbable organic bioelectronics in the brain
- 2023
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Ingår i: Nature Communications. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Bioelectronics can potentially complement classical therapies in nonchronic treatments, such as immunotherapy and cancer. In addition to functionality, minimally invasive implantation methods and bioresorbable materials are central to nonchronic treatments. The latter avoids the need for surgical removal after disease relief. Self-organizing substrate-free organic electrodes meet these criteria and integrate seamlessly into dynamic biological systems in ways difficult for classical rigid solid-state electronics. Here we place bioresorbable electrodes with a brain-matched shear modulus-made from water-dispersed nanoparticles in the brain-in the targeted area using a capillary thinner than a human hair. Thereafter, we show that an optional auxiliary module grows dendrites from the installed conductive structure to seamlessly embed neurons and modify the electrode's volume properties. We demonstrate that these soft electrodes set off a controlled cellular response in the brain when relaying external stimuli and that the biocompatible materials show no tissue damage after bioresorption. These findings encourage further investigation of temporary organic bioelectronics for nonchronic treatments assembled in vivo. Temporary bioelectronics can complement classical therapies in non-chronic treatments. Here, the authors describe the minimally invasive implantation of bioresorbable electrodes in the brain that form in situ from water-dispersed nanoparticles and show no tissue damage after bioresorption.
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| 3. |
- Jonasson, Klara J., et al.
(författare)
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Synthesis and characterisation of POCsp3OP supported Ni(II) hydroxo, hydroxycarbonyl and carbonate complexes
- 2018
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Ingår i: Polyhedron. - : Elsevier BV. - 0277-5387. ; 143, s. 132-137
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Tidskriftsartikel (refereegranskat)abstract
- A nickel(II) hydroxo complex (3) supported by a cyclohexyl based POCsp3OP pincer ligand (POCsp3OP = cis-1,3-Bis-(di-tert-butylphosphinito)cyclohexyl) is reported. Complex 3 reacts with CO to form the corresponding hydroxycarbonyl complex, (POCsp3OP)NiCOOH (4). Complex 3 is also reactive towards CO2, forming a bicarbonate species (5) that under reduced pressure loses 1/2 eq. of H2O and CO2 to give a binuclear, bridged carbonate complex (6). All compounds were characterized in the solid state by X-ray diffraction.
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| 4. |
- Mousa, Abdelrazek H., et al.
(författare)
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Aromatic PCN pincer palladium complexes : Forming and breaking CC bonds
- 2017
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Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 845, s. 157-164
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Tidskriftsartikel (refereegranskat)abstract
- Through a salt metathesis reaction, ( t-BuPCN)Pd-ONO2 (2) was prepared and used as a precursor for producing ( t-BuPCN)Pd-OH (3) and ( t-BuPCN)Pd-aryl acetylide complexes 4 (phenyl acetylide) and 5 (p-tolyl acetylide). The aryl acetylide complexes could also be prepared through another synthetic route: by condensation of 3 with the corresponding aryl acetylene. The reactivity of complexes 3 and 4 toward carbon dioxide was studied and it was found that both reactions give the hydrogen carbonate complex (6). The low reactivity of the Pd-acetylide bond was further confirmed by the fact that the propiolate complex undergoes decarboxylation to give 4. PCN palladium complexes are good catalysts for the decarboxylative cross coupling reactions between acetylene carboxylic acids and aryl halides. The yield of the cross coupling product was improved by adding a catalytic amount of CuI.
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| 5. |
- Mousa, Abdelrazek H., et al.
(författare)
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Carboxylation of the Ni-Me Bond in an Electron-Rich Unsymmetrical PCN Pincer Nickel Complex
- 2020
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Ingår i: Organometallics. - : American Chemical Society (ACS). - 0276-7333 .- 1520-6041. ; 39:9, s. 1553-1560
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis of a new unsymmetrical PCN ligand bearing tert-butyl groups on the phosphorus atom and isopropyl groups on the nitrogen donor atom is presented. It reacts with the commercially available Ni(DME)Br2 precursor to offer the corresponding t-BuPCNi-Pr pincer nickel bromide complex 1 together with a paramagnetic species, which was characterized as a tetrahedral nickel complex. Complex 1 reacts with MeMgCl to give the corresponding methyl complex 3. Carboxylation of complex 3 using 4 atm of CO2 gave the PCN nickel acetate complex 4 under mild reaction conditions comparable to those for the corresponding palladium complexes with PCP ligands.
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| 6. |
- Mousa, Abdelrazek H., et al.
(författare)
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Enhancing the Stability of Aromatic PCN Pincer Nickel Complexes by Incorporation of Pyridine as the Nitrogen Side Arm
- 2020
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Ingår i: European Journal of Inorganic Chemistry. - : Wiley. - 1434-1948 .- 1099-0682. ; 2020:45, s. 4270-4277
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Tidskriftsartikel (refereegranskat)abstract
- New PCNPy pincer nickel complexes have been synthesized through a short synthetic route. Incorporating pyridine as the nitrogen side arm facilitated the C–H activation in the PCN ligand and allowed the cyclometallation with nickel to take place at room temperature. Pyridine also enhanced the stability of β-hydrogen-containing alkyl complexes. Also, the symmetric NCN nickel complex with pyridine side arms was successfully obtained giving a rare example of such type of complexes to be prepared through direct C–H activation. Furthermore, preliminary results showed that the (PCNPy)Ni–Br is active in Kumada coupling reactions particularly the coupling of aryl halides with aryl Grignard reagents.
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| 7. |
- Mousa, Abdelrazek H., et al.
(författare)
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Method Matters: Exploring Alkoxysulfonate-Functionalized Poly(3,4-ethylenedioxythiophene) and Its Unintentional Self-Aggregating Copolymer toward Injectable Bioelectronics
- 2022
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 34:6, s. 2752-2763
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Tidskriftsartikel (refereegranskat)abstract
- Injectable bioelectronics could become an alternative or a complement to traditional drug treatments. To this end, a new self-doped p- type conducting PEDOT-S copolymer (A5) was synthesized. This copolymer formed highly water-dispersed nanoparticles and aggregated into a mixed ion-electron conducting hydrogel when injected into a tissue model. First, we synthetically repeated most of the published methods for PEDOT-S at the lab scale. Surprisingly, analysis using high-resolution matrix-assisted laser desorption ionization-mass spectroscopy showed that almost all the methods generated PEDOT-S derivatives with the same polymer lengths (i.e., oligomers, seven to eight monomers in average); thus, the polymer length cannot account for the differences in the conductivities reported earlier. The main difference, however, was that some methods generated an unintentional copolymer P(EDOT-S/EDOT-OH) that is more prone to aggregate and display higher conductivities in general than the PEDOT-S homopolymer. Based on this, we synthesized the PEDOT-S derivative A5, that displayed the highest film conductivity (33 S cm(-1)) among all PEDOT-S derivatives synthesized. Injecting A5 nanoparticles into the agarose gel cast with a physiological buffer generated a stable and highly conductive hydrogel (1-5 S cm(-1)), where no conductive structures were seen in agarose with the other PEDOT-S derivatives. Furthermore, the ion-treated A5 hydrogel remained stable and maintained initial conductivities for 7 months (the longest period tested) in pure water, and A5 mixed with Fe3O4 nanoparticles generated a magnetoconductive relay device in water. Thus, we have successfully synthesized a water-processable, syringe-injectable, and self-doped PEDOT-S polymer capable of forming a conductive hydrogel in tissue mimics, thereby paving a way for future applications within in vivo electronics.
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| 8. |
- Mousa, Abdelrazek H., et al.
(författare)
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Synthesis, Characterization, and Reactivity of PCN Pincer Nickel Complexes
- 2018
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Ingår i: Organometallics. - : American Chemical Society (ACS). - 0276-7333 .- 1520-6041. ; 37:15, s. 2581-2593
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Tidskriftsartikel (refereegranskat)abstract
- New diamagnetic nickel(II) complexes based on an unsymmetrical (1-(3-((ditert-butylphosphino)methyl)phenyl)-N,N-dimethyl-methanamine) (PCN) pincer ligand were synthesized and characterized by 1H, 31P{1H}, and 13C{1H} NMR spectroscopy. Their molecular structures were confirmed by X-ray diffraction. Oxidation to high-valent paramagnetic Ni(III) dihalide complexes was achieved through straightforward reaction of the corresponding diamagnetic halide complexes with anhydrous CuX2 (X = Cl, Br). In agreement with this, the complexes are active in Kharasch addition of CCl4 to olefins. The reaction of the hydroxo complex (8) and the amido complex (11) with CO2 produced the hydrogen carbonate and carbamate complexes, respectively. The hydrogen carbonate complex was converted to the dinuclear nickel carbonate complex (10). The methyl (13), phenyl (14), and p-tolylacetylide (15) complexes are also described in the current study providing the first example of the hydrocarbyl nickel complexes based on an unsymmetric aromatic pincer ligand. Furthermore, the reactivity of the methyl complex toward different electrophiles has been investigated, showing that C-C bond formation is possible with aryl halides, whereas the reaction with CO2 is sluggish.
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