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1. Synthesis and reactivity of a nickel( ii ) thioperoxide complex: demonstration of sulfide-mediated N ₂ O reduction

   https://doi.org/10.1039/C8SC02536C  

   Hartmann, Nathaniel J.; Wu, Guang; Hayton, Trevor W. (January 2018, Chemical Science)

   The thiohyponitrite ([SNNO] 2− ) complex, [K(18-crown-6)][L tBu Ni II (κ 2 -SNNO)] (L tBu = {(2,6- i Pr 2 C 6 H 3 )NC( t Bu)} 2 CH), extrudes N 2 under mild heating to yield [K(18-crown-6)][L tBu Ni II (η 2 -SO)] ( 1 ), along with minor products [K(18-crown-6)][L tBu Ni II (η 2 -OSSO)] ( 2 ) and [K(18-crown-6)][L tBu Ni II (η 2 -S 2 )] ( 3 ). Subsequent reaction of 1 with carbon monoxide (CO) results in the formation of [K(18-crown-6)][L tBu Ni II (η 2 -SCO)] ( 4 ), [K(18-crown-6)][L tBu Ni II ( S , O :κ 2 -SCO 2 )] ( 5 ), [K(18-crown-6)][L tBu Ni II (κ 2 -CO 3 )] ( 6 ), carbonyl sulfide (COS) ( 7 ), and [K(18-crown-6)][L tBu Ni II (S 2 CO)] ( 8 ). To rationalize the formation of these products we propose that 1 first reacts with CO to form [K(18-crown-6)][L tBu Ni II (S)] ( I ) and CO 2 , via O-atom abstraction. Subsequently, complex I reacts with CO or CO 2 to form 4 and 5 , respectively. Similarly, the formation of complex 6 and COS can be rationalized by the reaction of 1 with CO 2 to form a putative Ni( ii ) monothiopercarbonate, [K(18-crown-6)][L tBu Ni II (κ 2 -SOCO 2 )] ( 11 ). The Ni( ii ) monothiopercarbonate subsequently transfers a S-atom to CO to form COS and [K(18-crown-6)][L tBu Ni II (κ 2 -CO 3 )] ( 6 ). Finally, the formation of 8 can be rationalized by the reaction of COS with I . Critically, the observation of complexes 4 and 5 in the reaction mixture reveals the stepwise conversion of [K(18-crown-6)][L tBu Ni II (κ 2 -SNNO)] to 1 and then I , which represents the formal reduction of N 2 O by CO. 

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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. Quaternary cerium( iv ) containing fluorides exhibiting Ce ₃ F ₁₆ sheets and Ce ₆ F ₃₀ frameworks

   https://doi.org/10.1039/d0dt00616e  

   Ayer, Gyanendra B.; Klepov, Vladislav V.; Pace, Kristen A.; zur Loye, Hans-Conrad (May 2020, Dalton Transactions)

   null (Ed.)

   A series of new Ce( iv ) based fluorides with two different compositions, Cs 2 MCe 3 F 16 (M = Ni 2+ , Co 2+ , Mn 2+ , and Zn 2+ ) and Na 3 MCe 6 F 30 (M = Al 3+ , Ga 3+ , Fe 3+ , and Cr 3+ ) were synthesized as high quality single crystals via a mild hydrothermal route. The compounds with the composition Cs 2 MCe 3 F 16 (M = Ni 2+ , Co 2+ , Mn 2+ , and Zn 2+ ) crystallize in the hexagonal crystal system with space group P 6 3 / mmc and are isotypic with the uranium analogs, whereas the Na 3 MCe 6 F 30 (M = Al 3+ , Ga 3+ , Fe 3+ , and Cr 3+ ) compounds crystallize in the trigonal space group P 3̄ c 1 and are isotypic with the uranium and thorium analogs Na x MM′ 6 F 30 (M′ = Th, U). The Cs 2 MCe 3 F 16 compounds exhibit a complex 3D crystal structure constructed of edge-sharing cerium trimers, in which all three Ce atoms share a common μ 3 -F unit. The Na 3 MCe 6 F 30 compounds are constructed of edge- and vertex-sharing cerium polyhedra connected to each other to form Ce 6 F 30 6− framework, which can accommodate only relatively smaller trivalent cations (M 3+ = Al 3+ , Ga 3+ , Fe 3+ , and Cr 3+ ) as compared to uranium and thorium analogs. Magnetic susceptibility measurements were carried out on the samples of Cs 2 MCe 3 F 16 (M = Ni 2+ and Co 2+ ), which exhibit paramagnetic behavior. 

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4. ND70 Series Basaltic Glass Reference Materials for Volatile Element ( H₂O , CO₂ , S, Cl, F) Measurement and the C Ionisation Efficiency Suppression Effect of Water in Silicate Glasses in SIMS

   https://doi.org/10.1111/ggr.12572  

   Moussallam, Yves; Towbin, William Henry; Plank, Terry; Bureau, Hélène; Khodja, Hicham; Guan, Yunbin; Ma, Chi; Baker, Michael B; Stolper, Edward M; Naab, Fabian U; et al (July 2024, Geostandards and Geoanalytical Research)

   We present a new set of reference materials, the ND70‐series, forin situmeasurement of volatile elements (H₂O, CO₂, S, Cl, F) in silicate glass of basaltic composition. The materials were synthesised in piston cylinders at pressures of 1 to 1.5 GPa under volatile‐undersaturated conditions. They span mass fractions from 0 to 6%m/mH₂O, from 0 to 1.6%m/mCO₂and from 0 to 1%m/mS, Cl and F. The materials were characterised by elastic recoil detection analysis for H₂O, by nuclear reaction analysis for CO₂, by elemental analyser for CO₂, by Fourier transform infrared spectroscopy for H₂O and CO₂, by secondary ion mass spectrometry for H₂O, CO₂, S, Cl and F, and by electron probe microanalysis for CO₂, S, Cl and major elements. Comparison between expected and measured volatile amounts across techniques and institutions is excellent. It was found however that SIMS measurements of CO₂mass fractions using either Cs⁺or O⁻primary beams are strongly affected by the glass H₂O content. Reference materials have been made available to users at ion probe facilities in the US, Europe and Japan. Remaining reference materials are preserved at the Smithsonian National Museum of Natural History where they are freely available on loan to any researcher. 

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5. Reactivity of a biomimetic W( iv ) bis-dithiolene complex with CO ₂ leading to formate production and structural rearrangement

   https://doi.org/10.1039/c9dt03906f  

   Seo, Junhyeok; Shearer, Jason; Williard, Paul G.; Kim, Eunsuk (December 2019, Dalton Transactions)

   A mononuclear W( iv ) bis-dithiolene complex stabilized by an oxo ligand shows a reductive reactivity toward CO 2 , from which formate and a dinuclear W( v ) complex are generated. An unusual structural rearrangement was observed during the reaction. Structural and spectroscopic characterization for a novel triply bridged dinuclear W( v ) complex is reported. 

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