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1. Crystal structure of the [(THF)Cs(μ-η ⁵ :η ⁵ -Cp′) ₃ Yb] _n oligomer

   https://doi.org/10.1107/S2056989020008051  

   Huh, Daniel N.; Ziller, Joseph W.; Evans, William J. (July 2020, Acta Crystallographica Section E Crystallographic Communications)

   null (Ed.)

   The green compound poly[(tetrahydrofuran)tris[μ-η 5 :η 5 -1-(trimethylsilyl)cyclopentadienyl]caesium(I)ytterbium(II)], [CsYb(C 8 H 13 Si) 3 (C 4 H 8 O)] n or [(THF)Cs(μ-η 5 :η 5 -Cp′) 3 Yb II ] n was synthesized by reduction of a red THF solution of (C 5 H 4 SiMe 3 ) 3 Yb III with excess Cs metal and identified by X-ray diffraction. The compound crystallizes as a two-dimensional array of hexagons with alternating Cs I and Yb II ions at the vertices and cyclopentadienyl groups bridging each edge. This, based off the six-electron cyclopentadienyl rings occupying three coordination positions, gives a formally nine-coordinate tris(cyclopentadienyl) coordination environment to Yb and the Cs is ten-coordinate due to the three cyclopentadienyl rings and a coordinated molecule of THF. The complex comprises layers of Cs 3 Yb 3 hexagons with THF ligands and Me 3 Si groups in between the layers. The Yb—C metrical parameters are consistent with a 4 f 14 Yb II electron configuration. 

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2. Branching Ratio for O + H ₃ ⁺ Forming OH ⁺ + H ₂ and H ₂ O ⁺ + H

   https://doi.org/10.3847/1538-4357/ac41ce  

   Hillenbrand, Pierre-Michel; Ruette, Nathalie de; Urbain, Xavier; Savin, Daniel W. (March 2022, The Astrophysical Journal)

   Abstract The gas-phase reaction of O + H 3 + has two exothermic product channels: OH + + H 2 and H 2 O + + H. In the present study, we analyze experimental data from a merged-beams measurement to derive thermal rate coefficients resolved by product channel for the temperature range from 10 to 1000 K. Published astrochemical models either ignore the second product channel or apply a temperature-independent branching ratio of 70% versus 30% for the formation of OH + + H 2 versus H 2 O + + H, respectively, which originates from a single experimental data point measured at 295 K. Our results are consistent with this data point, but show a branching ratio that varies with temperature reaching 58% versus 42% at 10 K. We provide recommended rate coefficients for the two product channels for two cases, one where the initial fine-structure population of the O( 3 P J ) reactant is in its J = 2 ground state and the other one where it is in thermal equilibrium. 

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3. Redetermination of poly[di-μ ₃ -iodido-[μ-1,2- trans -(pyridin-4-yl)ethene-κ ² N : N ′]dicopper(I)]

   https://doi.org/10.1107/S2414314619001226  

   Neal, Henry C.; Tamtam, Harsha; Smucker, Bradley W.; Nesterov, Volodymyr V. (January 2019, IUCrData)

   The re-investigated structure of the title compound, [Cu 2 I 2 (C 12 H 10 N 2 )] n , a two-dimensional coordination polymer crystallizing with monoclinic ( P 2 1 / n ) symmetry, is based on data collected at 100 K, while the previously reported structure was obtained with data collected at 203 K [Blake et al. (1999). Cryst. Eng. 2 , 181–195]. The refinement of the crystal structure is greatly improved; for example, the wR 2 residual converges to 0.047 for 1532 independent data, versus wR 2 = 0.179 for 992 independent data in the 1999 study. 

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4. Isocyanide Substituent Influences Reductive Elimination versus Migratory Insertion in Reaction with an [Fe ₂ (μ-H) ₂ ] ²⁺ Complex

   https://doi.org/10.1021/acs.inorgchem.4c03256  

   John, Titto Sunil; Dobrzycki, Łukasz; Catalano, Vincent J; Murray, Leslie J (November 2024, Inorganic Chemistry)

   Iron hydrides are proposed reactive intermediates for N2 and CO conversion in industrial and biological processes. Here, we report a reactivity study of a low-coordinate di(μ-hydrido)diiron(II) complex, Fe2(μ-H)2L, where L2– is a bis(β-diketiminate) cyclophane, with isocyanides, which have electronic structures related to N2 and CO. The reaction outcome is influenced by the isocyanide substituent, with 2,6-xylyl isocyanide leading to H2 loss, to form a bis(μ-1,1-isocyanide)diiron(I) complex, whereas all of the other tested isocyanides insert into the Fe–H bond to give (μ-1,2-iminoformyl) complexes. Steric bulk of the isocyanide substituent determines the extent of insertion (i.e., into one or both Fe–H–Fe units) with tert-butyl isocyanide reacting to yield the mono-(μ-1,2-iminoformyl)diiron(II) complex, exclusively, and isopropyl- and methyl isocyanides affording the bis(μ-1,2-iminoformyl)diiron(II) products. Treatment of Fe2(μ-1,2-CHNtBu)(μ-H)L with 2,6-xylyl isocyanide (or XylNC) yields Fe2(μ-XylNC)2L and tert-butylaldimine as one of the organic products. 

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5. Conversion of He(2 ³ S ) to He ₂ ( a ³ Σ _u ⁺ ) in Liquid Helium

   https://doi.org/10.1021/acs.jpclett.8b02454  

   Nijjar, P.; Krylov, A. I.; Prezhdo, O. V.; Vilesov, A. F.; Wittig, C. (September 2018, The Journal of Physical Chemistry Letters)