Chemical Reviews
DOI: 10.1021/acs.chemrev.3c00326
Synthesis and bioactivity evaluation of novel acetamide-derived compounds bearing a methylsulfonyl unit
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Cellulose Dissolution, Modification, and the Derived Hydrogel: A Review
Cellulose-derived hydrogel: Dispersion of feedstock determines material performance. This review summarizes the currently developed solvents and modification methods that not only increase the dissolution of cellulose, but also are the strategies for forming cellulose-based hydrogels. Also, the “reinforcement” of cellulose-based hydrogels by physical and chemical techniques is introduced.
Abstract
The cellulose-based hydrogel has occupied a pivotal position in almost all walks of life. However, the native cellulose can not be directly used for preparing hydrogel due to the complex non-covalent interactions. Some literature has discussed the dissolution and modification of cellulose but has yet to address the influence of the pretreatment on the as-prepared hydrogels. Firstly, the “touching” of cellulose by derived and non-derived solvents was introduced, namely, the dissolution of cellulose. Secondly, the “conversion” of functional groups on the cellulose surface by special routes, which is the modification of cellulose. The above-mentioned two parts were intended to explain the changes in physicochemical properties of cellulose by these routes and their influences on the subsequent hydrogel preparation. Finally, the “reinforcement” of cellulose-based hydrogels by physical and chemical techniques was summarized, viz., improving the mechanical properties of cellulose-based hydrogels and the changes in the multi-level structure of the interior of cellulose-based hydrogels.
Stay Hydrated! Impact of Solvation Phenomena on the CO2 Reduction Reaction at Pb(100) and Ag(100) surfaces
Unraveling the selectivity puzzle: To reconcile the experimental and computational discrepancy of CO2 reduction to HCOOH and CO on Pb and Ag catalyst, we have incorporated solvation effects in our combined DFT/microkinetic study. Explicit solvation has a significant impact on reaction intermediate adsorption energies, resulting in CO selectivity on Ag and HCOOH selectivity on Pb surfaces, consistent with experimental findings.
Abstract
Herein, a comprehensive computational study of the impact of solvation on the reduction reaction of CO2 to formic acid (HCOOH) and carbon monoxide on Pb(100) and Ag(100) surfaces is presented. Results further the understanding of how solvation phenomena influence the adsorption energies of reaction intermediates. We applied an explicit solvation scheme harnessing a combined density functional theory (DFT)/microkinetic modeling approach for the CO2 reduction reaction. This approach reveals high selectivities for CO formation at Ag and HCOOH formation on Pb, resolving the prior disparity between ab initio calculations and experimental observations. Furthermore, the detailed analysis of adsorption energies of relevant reaction intermediates shows that the total number of hydrogen bonds formed by HCOO plays a primary role for the adsorption strength of intermediates and the electrocatalytic activity. Results emphasize the importance of explicit solvation for adsorption and electrochemical reaction phenomena on metal surfaces.
Mapping the Ultrafast Mechanistic Pathways of Co Photocatalysts in Pure Water through Time‐Resolved X‐ray Spectroscopy
Co-based molecular photocatalysts: Nanosecond optical and X-ray absorption spectroscopy with theoretical calculations reveal a complete mechanistic pathway followed by 3 Co-based photocatalysts in pure water and show that the protonation of the CoI intermediate can be enhanced through introduction of terminal hydrogen containing amine substituents that function as efficient proton relays.
Abstract
Nanosecond time-resolved X-ray (tr-XAS) and optical transient absorption spectroscopy (OTA) are applied to study 3 multimolecular photocatalytic systems with [Ru(bpy)3]2+photoabsorber, ascorbic acid electron donor and Co catalysts with methylene (1), hydroxomethylene (2) and methyl (3) amine substituents in pure water. OTA and tr-XAS of 1 and 2 show that the favored catalytic pathway involves reductive quenching of the excited photosensitizer and electron transfer to the catalyst to form a CoII square pyramidal intermediate with a bonded aqua molecule followed by a CoI square planar derivative that decays within ≈8 μs. By contrast, a CoI square pyramidal intermediate with a longer decay lifetime of ≈35 μs is formed from an analogous CoII geometry for 3 in H2O. These results highlight the protonation of CoI to form the elusive hydride species to be the rate limiting step and show that the catalytic rate can be enhanced through hydrogen containing pendant amines that act as H−H bond formation proton relays.
Corrigendum: Asparagusic Acid – A Unique Approach toward Effective Cellular Uptake of Therapeutics: Application, Biological Targets, and Chemical Properties
ChemMedChem, EarlyView.
Multiparametric Investigations on Solvation Behaviour and Spectral Shifts of Symmetric Aromatic Diselenides: A case study of Diphenyldiselenide
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A Direct Route to Tetrahydropyridazine Derivatives via DMAP‐Catalyzed [4+2] Annulation of Allenoates with Arylazosulfones
![A Direct Route to Tetrahydropyridazine Derivatives via DMAP-Catalyzed [4+2] Annulation of Allenoates with Arylazosulfones](https://onlinelibrary.wiley.com/cms/asset/f30cf5df-a30f-4aaf-a98e-b2c2731724d6/cjoc202300369-toc-0001-m.png)
A facile and efficient DMAP-catalyzed [4+2] annulation of allenoates with arylazosulfones is developed for the synthesis of tetrahydropyridazine derivatives under mild and metal-free conditions, and this tandem cycloaddition exhibits high functional group tolerance and easy manipulation. In addition, the tetrahydropyridazine derivatives can be transformed into pyridazin-3-one derivatives in the presence of DDQ.
Comprehensive Summary
Herein, a DMAP-catalyzed [4+2] annulation of α-substituted allenoates with arylazosulfones is reported, which affords facile access to tetrahydropyridazine derivative in synthetically useful yields. This reaction features mild conditions and good functional group tolerance. Moreover, the resultant products can be readily transformed into pyridazin-3-one derivatives in the presence of DDQ.
π‐Extended End Groups Enable High‐Performance All‐Polymer Solar Cells with Near‐Infrared Absorption
A polymer acceptor PNT with expanded CPNM end groups was developed, which exhibited the increased molecular rigidity and broaden absorption spectrum. And the all-PSCs achieved a power conversion efficiency of 13.7% with a high short-circuit current density (J SC = 24.4 mA·cm−2).
Comprehensive Summary
Narrow-bandgap n-type polymers are essential for advancing the development of all-polymer solar cells (all-PSCs). Herein, we developed a novel polymer acceptor PNT with π-extended 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1-ylidene) malononitrile (CPNM) end groups. Compared to commonly used 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1ylidene) malononitrile (IC) units, CPNM units have a further extended fused ring, providing the PNT polymer with extended absorption into the near-IR region (903 nm) and exhibiting a narrow optical bandgap (1.37 eV). Furthermore, PNT exhibits a high electron mobility (6.79 × 10−4 cm2·V−1·S−1) and a relatively high-lying lowest unoccupied molecular orbital (LUMO) energy level of −3.80 eV. When blended with PBDB-T, all-PSC achieves a power conversion efficiency (PCE) of 13.7% and a high short-circuit current density (J SC) of 24.4 mA·cm−2, mainly attributed to broad absorption (600—900 nm) and efficient charge separation and collection. Our study provides a promising polymer acceptor for all-PSCs and demonstrates that π-extended CPNM units are important to achieve high-performance for all-PSCs.
Visible Light‐Mediated Cobalt and Photoredox Dual‐Catalyzed Asymmetric Reductive Coupling for Axially Chiral Secondary Alcohols
Cobalt/photoredox dual-catalyzed asymmetric reductive Grignard-type addition of aryl iodides with axially prochiral biaryl dialdehydes was developed, leading to the direct construction of axially chiral secondary alcohols in good yields with high stereoselectivity, enabled by desymmetrization followed by efficient kinetic recognition of diastereomers and kinetic resolution.
Comprehensive Summary
Secondary alcohols bearing both axial and central chirality comprise attractive biological activity and exhibit excellent chiral induction in asymmetric reactions. However, only very limited asymmetric catalytic approaches were developed for their synthesis. We herein describe visible light-mediated cobalt-catalyzed asymmetric reductive Grignard-type addition of aryl iodides with axially prochiral biaryl dialdehydes leading to the direct construction of axially chiral secondary alcohols. Preliminary mechanistic studies indicate that efficient kinetic recognition of diastereomers might occur for axially prochiral dialdehydes to improve the stereoselectivity, which might open a new avenue for the challenging cascade construction of multiple chiral elements. This protocol features excellent enantio- and diastereoselectivity, green and mild conditions, simple operation, and broad substrate scope, providing a modular platform for the synthesis of secondary axially chiral alcohols.