To study systems able to sustain intramolecular proton-transfer, we have prepared a series of six aminofulvene aldimines including several labeled with (15)N and (2)H. These compounds show coupling constants through the hydrogen bond, (1h)J((15)N- (1)H) and (2h)J((15)N-(15)N). The position of the tautomeric equilibria, i.e., on what nitrogen atom is the proton, was determined in the solid state and in solution. The crystal structure of N[[5-[(phenylamino)methylene]-1,3-cyclopentadien-1-yl]methylene]pyrrole-1-amine (3) has been determined by X-ray analysis. In solution, both N-H and C-H tautomers were observed and their structures assigned by NMR spectroscopy. Particularly useful is the value of the (1)J((15)N-(1)H) coupling constant.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jo010625v | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Computerized chest tomography (CT)-guided screening in populations at risk for lung cancer has increased the detection of preinvasive subsolid nodules, which progress to solid invasive adenocarcinoma. Despite the clinical significance, there is a lack of effective therapies for intercepting the progression of preinvasive to invasive adenocarcinoma. To uncover determinants of early disease emergence and progression, we used integrated single-cell approaches, including scRNA-seq, multiplexed imaging mass cytometry and spatial transcriptomics, to construct the first high-resolution map of the composition, lineage/functional states, developmental trajectories and multicellular crosstalk networks from microdissected non-solid (preinvasive) and solid compartments (invasive) of individual part-solid nodules.
View Article and Find Full Text PDFMethacrylate-based copolymers as tunable hosts for triplet-triplet annihilation upconversion.
Mater Adv
January 2025
Department of Materials Science and Metallurgy, University of Cambridge CB3 0FS UK
The ability to convert light to higher energies through triplet-triplet annihilation upconversion (TTA-UC) is attractive for a range of applications including solar energy harvesting, bioimaging and anti-counterfeiting. Practical applications require integration of the TTA-UC chromophores within a suitable host, which leads to a compromise between the high upconversion efficiencies achievable in liquids and the durability of solids. Herein, we present a series of methacrylate copolymers as TTA-UC hosts, in which the glass transition temperature ( ), and hence upconversion efficiency can be tuned by varying the co-monomer ratios (-hexyl methacrylate (HMA) and 2,2,2-trifluoroethyl methacrylate (TFEMA)).
View Article and Find Full Text PDFMechanically stable polymer networks incorporating polymeric ionic liquids for enhanced conductivity in solid-state electrolytes.
Des Monomers Polym
January 2025
Leibniz-Institut für Polymerforschung Dresden e.V, Dresden, Germany.
Enhancing both ionic conductivity and mechanical robustness remains a major challenge in designing solid-state electrolytes for lithium batteries. This work presents a novel approach in designing mechanically robust and highly conductive solid-state electrolytes, which involves ionic liquid-based cross-linked polymer networks incorporating polymeric ionic liquids (PILs). First, linear PILs with different side groups were synthesized for optimizing the structure.
View Article and Find Full Text PDFImpact of Mg Substitution on the Structure, Stability, and Properties of the NaFeF Weberite Cathode.
ACS Mater Au
January 2025
Materials Department, University of California Santa Barbara, California 93106, United States.
Of the few weberite-type Na-ion cathodes explored to date, NaFeF exhibits the best performance, with capacities up to 184 mAh/g and energy densities up to 550 Wh/kg reported for this material. However, the development of robust structure-property relationships for this material is complicated by its tendency to form as a mixture of metastable polymorphs, and transform to a lower-energy Na FeF perovskite compound during electrochemical cycling. Our first-principles-guided exploration of Fe-based weberite solid solutions with redox-inactive Mg and Al predicts an enhanced thermodynamic stability of NaMg Fe F as the Mg content is increased, and the = 0.
View Article and Find Full Text PDFTi Doping Decreases Mn and Ni Dissolution from High-Voltage LiNiMnO Cathodes.
ACS Mater Au
January 2025
Solid State and Structural Chemistry Unit, IISc, Bengaluru 560012, Karnataka, India.
LiNiMnO (LNMO), with its high operating voltage, is a favorable cathode material for lithium-ion batteries. However, Ni and Mn dissolution and the associated low cycle life limit their widespread adoption. In this work, we investigate titanium doping as a strategy to mitigate Mn and Ni dissolution from LNMO electrodes.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!