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1. 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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2. New germanate and mixed cobalt germanate salt inclusion materials: [(Rb ₆ F)(Rb ₄ F)][Ge ₁₄ O ₃₂ ] and [(Rb ₆ F)(Rb _3.1 Co _0.9 F _0.96 )][Co _3.8 Ge _10.2 O ₃₀ F ₂ ]

   https://doi.org/10.1039/D0CE01099E  

   Carone, Darren; Usman, Mohammad; Klepov, Vladislav V.; Smith, Mark D.; Kocevski, Vancho; Besmann, Theodore M.; zur Loye, Hans-Conrad (December 2020, CrystEngComm)

   null (Ed.)

   Single crystals of two new germanates, [(Rb 6 F)(Rb 4 F)][Ge 14 O 32 ] and [(Rb 6 F)(Rb 3.1 Co 0.9 F 0.96 )][Co 3.8 Ge 10.2 O 30 F 2 ], were synthesized via high temperature RbCl/RbF flux growth. Both compounds crystallize in the cubic space group F 4̄3 m and possess the germanium framework of the previously reported salt inclusion material (SIM), [(Cs 6 F)(Cs 3 AgF)][Ge 14 O 32 ], related to the Ge 7 O 16 zeolitic family. These materials demonstrate the ability to accommodate a variety of salt-inclusions, and exhibit chemical flexibility enabling modifications of the framework through incorporation of Co. Alteration of the salt-inclusion led to intrinsic luminescence of [(Rb 6 F)(Rb 4 F)][Ge 14 O 32 ] while modification of the framework resulted in an unanticipated Rb/Co salt/inclusion in [(Rb 6 F)(Rb 3.1 Co 0.9 F 0.96 )][Co 3.8 Ge 10.2 O 30 F 2 ]. Fluorescence measurements were performed on [(Rb 6 F)(Rb 4 F)][Ge 14 O 32 ]. First-principles calculations in the form of density functional theory (DFT) were performed for [(Rb 6 F)(Rb 3.1 Co 0.9 F 0.96 )][Co 3.8 Ge 10.2 O 30 F 2 ] to elucidate its electronic and magnetic properties, and stability at 0 K. 

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3. Alkali Metal Carbatrane Compounds [Tism ^PriBenz ]M: Synthesis and Structural Characterization of a Complete Series of Monomeric Alkali Metal Alkyl Compounds

   https://doi.org/10.1021/acs.organomet.3c00349  

   Vaccaro, David A; Parkin, Gerard (November 2023, Organometallics)

   The tris[(1-isopropylbenzimidazol-2-yl)dimethylsilyl]methyl thallium compound, [TismPriBenz]Tl, reacts with Li, Na, K and Rb afford the respective alkali metal carbatrane complex, [TismPriBenz]M (M = Li, Na, K, Rb), while the cesium complex [TismPriBenz]Cs is obtained via the reaction of [TismPriBenz]Li with CsF. These carbatrane compounds [TismPriBenz]M (M = Li, Na, K, Rb and Cs) constitute the first complete series of structurally characterized monomeric alkyl compounds of the nonradioactive alkali metals. 

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4. Cerium( iv ) complexes with guanidinate ligands: intense colors and anomalous electronic structures

   https://doi.org/10.1039/D0SC05193D  

   Qiao, Yusen; Yin, Haolin; Moreau, Liane M.; Feng, Rulin; Higgins, Robert F.; Manor, Brian C.; Carroll, Patrick J.; Booth, Corwin H.; Autschbach, Jochen; Schelter, Eric J. (March 2021, Chemical Science)

   null (Ed.)

   A series of cerium( iv ) mixed-ligand guanidinate–amide complexes, {[(Me 3 Si) 2 NC(N i Pr) 2 ] x Ce IV [N(SiMe 3 ) 2 ] 3−x } + ( x = 0–3), was prepared by chemical oxidation of the corresponding cerium( iii ) complexes, where x = 1 and 2 represent novel complexes. The Ce( iv ) complexes exhibited a range of intense colors, including red, black, cyan, and green. Notably, increasing the number of the guanidinate ligands from zero to three resulted in significant redshift of the absorption bands from 503 nm (2.48 eV) to 785 nm (1.58 eV) in THF. X-ray absorption near edge structure (XANES) spectra indicated increasing f occupancy ( n f ) with more guanidinate ligands, and revealed the multiconfigurational ground states for all Ce( iv ) complexes. Cyclic voltammetry experiments demonstrated less stabilization of the Ce( iv ) oxidation state with more guanidinate ligands. Moreover, the Ce( iv ) tris(guanidinate) complex exhibited temperature independent paramagnetism (TIP) arising from the small energy gap between the ground- and excited states with considerable magnetic moments. Computational analysis suggested that the origin of the low energy absorption bands was a charge transfer between guanidinate π orbitals that were close in energy to the unoccupied Ce 4f orbitals. However, the incorporation of sterically hindered guanidinate ligands inhibited optimal overlaps between Ce 5d and ligand N 2p orbitals. As a result, there was an overall decrease of ligand-to-metal donation and a less stabilized Ce( iv ) oxidation state, while at the same time, more of the donated electron density ended up in the 4f shell. The results indicate that incorporating guanidinate ligands into Ce( iv ) complexes gives rise to intense charge transfer bands and noteworthy electronic structures, providing insights into the stabilization of tetravalent lanthanide oxidation states. 

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5. 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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