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1. Charge-transfer-enhanced d – d emission in antiferromagnetic NiPS3

   https://doi.org/10.1063/5.0107065  

   Tan, Qishuo; Luo, Weijun; Li, Tianshu; Cao, Jun; Kitadai, Hikari; Wang, Xingzhi; Ling, Xi (November 2022, Applied Physics Reviews)

   The d electron plays a significant role in determining and controlling the properties of magnetic materials. However, the d electron transitions, especially d–d emission, have rarely been observed in magnetic materials due to the forbidden selection rules. Here, we report an observation of d–d emission in antiferromagnetic nickel phosphorus trisulfides (NiPS3) and its strong enhancement by stacking it with monolayer tungsten disulfide (WS2). We attribute the observation of the strong d–d emission enhancement to the charge transfer between NiPS3 and WS2 in the type-I heterostructure. The d–d emission peak splits into two peaks, D1 and D2, at low temperature below 150 K, from where an energy splitting due to the trigonal crystal field is measured as 105 meV. Moreover, we find that the d–d emissions in NiPS3 are nonpolarized lights, showing no dependence on the zigzag antiferromagnetic configuration. These results reveal rich fundamental information on the electronic and optical properties of emerging van der Waals antiferromagnetic NiPS3. 

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2. Intramolecular Charge Transfer in Antiaromatic Donor/Acceptor‐Fused s ‐Indacenes

   https://doi.org/10.1002/anie.202420989  

   Demachkie, Isabella_S; Miller, Michael_P; Warren, Gabrielle_I; Barker, Joshua_E; Strand, Eric_T; Zakharov, Lev_N; Haley, Michael_M (December 2024, Angewandte Chemie International Edition)

   Abstract Herein we report the synthesis and characterization of four donor/acceptor‐fuseds‐indacenes via the late‐stage oxidation of a family of unsymmetrical benzofuran/benzothiophene‐s‐indacene regioisomers. A thorough study of their properties through experimental and computational analysis has revealed the effect of asymmetry on the molecular properties associated with antiaromaticity, as well as a strong correlation between antiaromaticity and intramolecular charge transfer (ICT). The strength of the charge transfer depends on the fusion orientation of the donor and acceptor motifs relative to thes‐indacene core. The two most antiaromatic oxidized isomers exhibit strong evidence of ICT with 30 and 40 nm solvatochromic shifts. 

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3. Resonant Vibrational Enhancement of Downhill Energy Transfer in the C -Phycocyanin Chromophore Dimer

   https://doi.org/10.1021/acs.jpclett.4c02386  

   Sohoni, Siddhartha; Wu, Ping-Jui_Eric; Shen, Qijie; Lloyd, Lawson_T; MacGregor-Chatwin, Craig; Hitchcock, Andrew; Engel, Gregory_S (November 2024, The Journal of Physical Chemistry Letters)
4. In Situ Optical Quantification of Extracellular Electron Transfer Using Plasmonic Metal Oxide Nanocrystals**

   https://doi.org/10.1002/celc.202101423  

   Graham, Austin_J; Gibbs, Stephen_L; Saez_Cabezas, Camila_A; Wang, Yongdan; Green, Allison_M; Milliron, Delia_J; Keitz, Benjamin_K (February 2022, ChemElectroChem)

   Abstract Extracellular electron transfer (EET) is a critical form of microbial metabolism that enables respiration on a variety of inorganic substrates, including metal oxides. However, quantifying current generated by electroactive bacteria has been predominately limited to biofilms formed on electrodes. To address this, we developed a platform for quantifying EET flux from cell suspensions using aqueous dispersions of infrared plasmonic tin‐doped indium oxide nanocrystals. Tracking the change in optical extinction during electron transfer enabled quantification of current generated by planktonicShewanella oneidensiscultures. Using this method, we differentiated between starved and actively respiring cells, cells of varying genotype, and cells engineered to differentially express a key EET gene using an inducible genetic circuit. Overall, our results validate the utility of colloidally stable plasmonic metal oxide nanocrystals as quantitative biosensors in aqueous environments and contribute to a fundamental understanding of planktonicS. oneidensiselectrophysiology using simplein situspectroscopy. 

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5. Radical cascade synthesis of azoles via tandem hydrogen atom transfer

   https://doi.org/10.1039/c9sc06239d  

   Chen, Andrew D.; Herbort, James H.; Wappes, Ethan A.; Nakafuku, Kohki M.; Mustafa, Darsheed N.; Nagib, David A. (March 2020, Chemical Science)

   null (Ed.)

   A radical cascade strategy for the modular synthesis of five-membered heteroarenes ( e.g. oxazoles, imidazoles) from feedstock reagents ( e.g. alcohols, amines, nitriles) has been developed. This double C–H oxidation is enabled by in situ generated imidate and acyloxy radicals, which afford regio- and chemo-selective β C–H bis-functionalization. The broad synthetic utility of this tandem hydrogen atom transfer (HAT) approach to access azoles is included, along with experiments and computations that provide insight into the selectivity and mechanism of both HAT events. 

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