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1. Sr(Ag _1−x Li _x ) ₂ Se ₂ and [Sr ₃ Se ₂ ][(Ag _1−x Li _x ) ₂ Se ₂ ] Tunable Direct Band Gap Semiconductors

   https://doi.org/10.1002/anie.202301191  

   Zhou, Xiuquan; Wilfong, Brandon; Chen, Xinglong; Laing, Craig; Pandey, Indra R.; Chen, Ying‐Pin; Chen, Yu‐Sheng; Chung, Duck‐Young; Kanatzidis, Mercouri G. (March 2023, Angewandte Chemie International Edition)

   Abstract Synthesizing solids in molten fluxes enables the rapid diffusion of soluble species at temperatures lower than in solid‐state reactions, leading to crystal formation of kinetically stable compounds. In this study, we demonstrate the effectiveness of mixed hydroxide and halide fluxes in synthesizing complex Sr/Ag/Se in mixed LiOH/LiCl. We have accessed a series of two‐dimensional Sr(Ag_1−xLi_x)₂Se₂layered phases. With increased LiOH/LiCl ratio or reaction temperature, Li partially substituted Ag to form solid solutions of Sr(Ag_1−xLi_x)₂Se₂withxup to 0.45. In addition, a new type of intergrowth compound [Sr₃Se₂][(Ag_1−xLi_x)₂Se₂] was synthesized upon further reaction of Sr(Ag_1−xLi_x)₂Se₂with SrSe. Both Sr(Ag_1−xLi_x)₂Se₂and [Sr₃Se₂][(Ag_1−xLi_x)₂Se₂] exhibit a direct band gap, which increases with increasing Li substitution (x). Therefore, the band gap of Sr(Ag_1−xLi_x)₂Se₂can be precisely tuned via fine‐tuningxthat is controlled by only the flux ratio and temperature. 

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2. Comparative performance of Fe‐ MO_x / SiO₂ (M = V, Mn, Co, Ni, Cu, Mo) and FeO_x / SiO₂ catalysts in reductive liquefaction of switchgrass in ethanol

   https://doi.org/10.1002/bbb.2720  

   Amarasekara, Ananda S; Morales, Gabriel Murillo; Kommalapati, Raghava R (March 2025, Biofuels, Bioproducts and Biorefining)

   Abstract The catalytic hydrothermal liquefaction of biomass under a hydrogen atmosphere is a promising technology to produce stable biocrude oil as a sustainable alternative to petroleum crude. A series of iron‐based non‐noble mix metal‐oxide‐on‐silica catalysts were evaluated to mimic the natural transformation that may have led to the conversion of terrestrial biomass to fossilized fuels. Switchgrass powder was liquefied to a stable bio‐oil with a 71.2% yield by using FeO_x/SiO₂catalyst in ethanol under a 5.5 MPa hydrogen atmosphere at 210 °C. The use of Fe‐MO_x/SiO₂(M = V, Mn, Co, Ni, Cu and Mo) type bimetallic oxide catalysts instead of FeO_x/SiO₂can produce improvements in liquefaction yields by using Mn, Co, Ni, and Cu as the second metal. The highest liquefaction yield of 78.8% was observed with the Fe‐CuO_x/SiO₂catalyst. Liquefaction oils were formed that were composed of complex mixtures of C6‐C12 alcohols, esters, aldehydes, and phenols. The lignin products:holocellulose products ratio changed in the range 0.35 to 0.15 and the composition of oils changed significantly with the use of mixed metal oxides in place of single metal FeO_x/SiO₂The most effective catalyst, Fe‐CuO_x/SiO₂could be reused in five cycles with a small loss in liquefaction yield from 78.8% to 70.0% after four reuse cycles and after regeneration of the catalyst at 500 °C for 3 h in air. 

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3. Copper’s Role in the Photoluminescence of Ag _1–x Cu _x InS ₂ Nanocrystals, from Copper-Doped AgInS ₂ ( x ∼ 0) to CuInS ₂ ( x = 1)

   https://doi.org/10.1021/acs.nanolett.8b04905  

   Hughes, Kira E.; Ostheller, Sarah R.; Nelson, Heidi D.; Gamelin, Daniel R. (January 2019, Nano Letters)
4. Room temperature synthesis of UO _2+x nanocrystals and thin films via hydrolysis of uranium( iv ) complexes

   https://doi.org/10.1039/D1QI01248G  

   Murillo, Jesse; Panda, Debiprasad; Chakrabarti, Subhananda; Hattori, Alex; Griego, Leonel; Chava, Venkata S.; Sreenivasan, Sreeprasad T.; Ramana, Chintalapalle V.; Fortier, Skye (January 2022, Inorganic Chemistry Frontiers)

   Methods for the straightforward, room temperature synthesis of UO 2+ x nanoparticles and thin films using solution processable, molecular uranium( iv ) compounds is described. Ultra-small uranium dioxide nanoparticles are synthesized from the hydrolysis of either U(ditox) 4 (ditox = − OCH t Bu 2 ) (1) or U(CH 2 SiMe 2 NSiMe 3 )[N(SiMe 3 ) 2 ] 2 (2) via addition of water to stirring solutions of the compounds in non-polar solvents to give UO 2 -1 and UO 2 -2, respectively. The structural characteristics of the uranium dioxide nanoparticles were characterized using powder X-ray diffraction (pXRD), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. The pXRD results affirm the cubic fluorite structure expected for UO 2 nanoparticles. The nanocrystallinity of UO 2 -1 and UO 2 -2 were substantiated by bright-field HRTEM images and fast Fourier transform (FFT) patterns. The HRTEM analysis also shows the nanoparticles fall within the ultra-small regime possessing sizes of ∼3 nm with uniform distribution. Additionally, we demonstrate the versatility of 1 as a uranium dioxide precursor, showing that it can be readily sublimed onto glass or silicon substrates and subsequently hydrolyzed to give UO 2+ x thin films. 

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5. Polysaccharide‐based H₂S donors: Thiol‐ene functionalization of amylopectin with H₂S ‐releasing N ‐thiocarboxyanhydrides

   https://doi.org/10.1002/pol.20240262  

   Chinn, Abigail F; Williams, Noah R; Miller, Kevin M; Matson, John B (September 2024, Journal of Polymer Science)

   Abstract Polymeric donors of gasotransmitters, gaseous signaling molecules such as hydrogen sulfide, nitric oxide, and carbon monoxide, hold potential for localized and extended delivery of these reactive gases. Examples of gasotransmitter donors based on polysaccharides are limited despite the availability and generally low toxicity of this broad class of polymers. In this work, we sought to create a polysaccharide H₂S donor by covalently attachingN‐thiocarboxyanhydrides (NTAs) to amylopectin, the major component of starch. To accomplish this, we added an allyl group to an NTA, which can spontaneously hydrolyze to release carbonyl sulfide and ultimately H₂S via the ubiquitous enzyme carbonic anhydrase, and then coupled it to thiol‐functionalized amylopectin of three different molecular weights (MWs) through thiol‐ene “click” photochemistry. We also varied the degree of substitution (DS) of the NTA along the amylopectin backbone. H₂S release studies on the six samples, termed amyl‐NTAs, with variable MWs (three) and DS values (two), revealed that lower MW and higher DS led to faster release. Finally, dynamic light scattering experiments suggested that aggregation increased with MW, which may also have affected H₂S release rates. Collectively, these studies present a new synthetic method to produce polysaccharide H₂S donors for applications in the biomedical field. 

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