We report a simple and effective approach to organic molecules exhibiting bright circularly polarized luminescence (CPL) by combining a chiral cyclic molecular scaffold and multiple excimer-enabling moieties. An α-cyclodextrin (CyD) scaffold was modified with six pyrenyl groups to obtain pyrene-cyclodextrins (PCDs) in a one-step synthesis from commercially available compounds. The PCDs exhibited high molar extinction coefficients (ϵ≈10 M cm ), polarized emission with a good dissymmetry factor (|g |≈10 ), and quantum yield (Φ ≈0.5). Owing to the excellent photophysical properties of the PCDs, the circularly polarized luminescence brightness (B ) reached 340 M cm . Photophysical and chiroptical studies of the PCDs with only five pyrene units and with linkers of various lengths connecting the CyD with the pyrene units revealed that the formation of a pyrene excimer in a spatially crowded environment is crucial for CPL anisotropy. This study paves the way for the development of bright CPL organic molecules.
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http://dx.doi.org/10.1002/anie.202114700 | DOI Listing |
Curr Org Synth
January 2025
Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, I.R. Iran.
Carbodiimides (R-N=C=N-R) are well-known intermediates for the preparation of a variety of N-containing compounds, including heterocycles and amide linkages. Be-cause of their high reactivity and easy availability, carbodiimides have been broadly used as building blocks in the synthesis of structurally complex and diverse heterocyclic com-pounds in multi-component reactions (MCRs). Recent advances in diversity-oriented syn-thesis with carbodiimide-based MCRs are discussed in this minireview and are classified into different sections based on the key transformation involved in the reactions, such as heteroannulation and nucleophilic addition reactions which containing metal-catalyzed re-actions, multi-component reactions, and catalyst-free reactions subsections.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
The tunability of the energy bandgap in the near-infrared (NIR) range uniquely positions colloidal lead sulfide (PbS) quantum dots (QDs) as a versatile material to enhance the performance of existing perovskite and silicon solar cells in tandem architectures. The desired narrow bandgap (NBG) PbS QDs exhibit polar (111) and nonpolar (100) terminal facets, making effective surface passivation through ligand engineering highly challenging. Despite recent breakthroughs in surface ligand engineering, NBG PbS QDs suffer from uncontrolled agglomeration in solid films, leading to increased energy disorder and trap formation.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Henan Provincial Engineering and Technology Research Center for Precise Synthesis of Fluorine-Containing Drugs. College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, 455000, P. R. China.
A TEMPO-mediated β-ketoalkylation of enaminoesters with cyclopropanols under metal-free conditions is herein described. This reaction provides a straightforward and highly efficient route to β-keto alkyl substituted enaminoesters for the first time, which could be rapidly and efficiently converted into synthetically useful 2-alkoxycarbonyl functionalized 1,5-diketones. Moreover, the practicability of this protocol is successfully demonstrated by scale-up experiments and the late-stage functionalization of natural products and pharmaceutically relevant molecules.
View Article and Find Full Text PDFSmall
January 2025
MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Shaanxi Province Key Laboratory of Advanced Materials and Mesoscopic Physics, School of Physics, Xi'an Jiaotong University, Xi'an, 710049, P. R. China.
Owing to the nanoscale thickness, excellent mechanical and chemical stabilities, 2D materials including graphene and hexagonal boron nitride have emerged as promising artificial solid electrolyte interphase (SEI) candidates for lithium metal batteries. However, whether the implementation of 2D materials is beneficial to electrochemical performance remains controversial, and the key to confining the electroplated Li beneath the 2D materials remains elusive. Here, a nanocrystalline graphene (NG) film is synthesized on high-carbon Cu and the Li plating/stripping behavior on Cu grown with different 2D materials is investigated.
View Article and Find Full Text PDFJ Org Chem
January 2025
Division of Theoretical Chemistry, IFM, Linköping University, 58183 Linköping, Sweden.
The harmonic oscillator model of aromaticity (HOMA) offers a straightforward route to quantifying aromaticity that requires no other information than the bond lengths of the conjugated ring in question. Given that such information is often readily obtainable from quantum-chemical calculations, it is pertinent to improve this parametrized model as much as possible. Here, a new version of HOMA is presented where, atypically, the corresponding parameters are derived from the actual bond lengths of both aromatic and antiaromatic (rather than nonaromatic) reference compounds, as calculated with a high-level method.
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