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1. Robust, remeltable and remarkably simple to prepare biomass–sulfur composites

   https://doi.org/10.1039/d0ma00538j  

   Lauer, Moira K.; Karunarathna, Menisha S.; Tennyson, Andrew G.; Smith, Rhett C. (October 2020, Materials Advances)

   null (Ed.)

   Lignocellulosic biomass holds a tremendous opportunity for transformation into carbon-negative materials, yet the expense of separating biomass into its cellulose and lignin components remains a primary economic barrier to biomass utilization. Herein is reported a simple procedure to convert several biomass-derived materials into robust, recyclable composites through their reaction with elemental sulfur by inverse vulcanization, a process in which olefins are crosslinked by sulfur chains. In an effort to understand the chemistry and the parameters leading to the strength of these composites, sulfur was reacted with four biomass-derivative comonomers: (1) unmodified peanut shell powder, (2) allyl peanut shells, (3) ‘mock’ allyl peanut shells (a mixture containing independently-prepared allyl cellulose and allyl lignin), or (4) peanut shells that have been defatted by extraction of peanut oil. The reactions of these materials with sulfur produce the biomass–sulfur composites PSx , APSx , mAPSx and dfPSx , respectively, where x = wt% sulfur in the monomer feed. The influence of biomass : sulfur ratio was assessed for PSx and APSx . Thermal/mechanical properties of composites were evaluated for comparison to commercial materials. Remarkably, unmodified peanut shell flour can simply be heated with elemental sulfur to produce composites having flexural/compressive strengths exceeding those of Portland cement, an effect traced to the presence of olefin-bearing peanut oil in the peanut shells. When allylated peanut shells are used in this process, a composite having twice the compressive strength of Portland cement is attained. 

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2. An η ³ ‐Bound Allyl Ligand on Magnesium in a Mechanochemically Generated Mg/K Allyl Complex

   https://doi.org/10.1002/anie.201916410  

   Koby, Ross F.; Doerr, Alicia M.; Rightmire, Nicholas R.; Schley, Nathan D.; Long, Brian K.; Hanusa, Timothy P. (June 2020, Angewandte Chemie International Edition)

   Abstract Milling two equivalents of K[1,3‐(SiMe₃)₂C₃H₃] (=K[A′]) with MgX₂(X=Cl, Br) produces the allyl complex [K₂MgA′₄] (1). Crystals grown from toluene are of the solvated species [((η⁶‐tol)K)₂MgA′₄] ([1⋅2(tol)]), a trimetallic monomer with both bridging and terminal (η¹) allyl ligands. When recrystallized from hexanes, the unsolvated1forms a 2D coordination polymer, in which the Mg is surrounded by three allyl ligands. The C−C bond lengths differ by only 0.028 Å, indicating virtually complete electron delocalization. This is an unprecedented coordination mode for an allyl ligand bound to Mg. DFT calculations indicate that in isolation, an η³‐allyl configuration on Mg is energetically preferred over the η¹‐ (σ‐bonded) arrangement, but the Mg must be in a low coordination environment for it to be experimentally realized. Methyl methacrylate is effectively polymerized by1, with activities that are comparable to K[A′] and greater than the homometallic magnesium complex [{MgA′₂}₂]. 

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3. Crystal structures of three salts of the triphenylsulfonium ion

   https://doi.org/10.1107/S2056989025000118  

   Artis, Rylan; Callaway, Waylan; Heyward, Elizabeth; Reyes, Naomi; Roberts, Gavin; Van_Ostenbridge, Kaitlyn; Padgett, Clifford W; Lynch, Will E (February 2025, Acta Crystallographica Section E Crystallographic Communications)

   The reactions of triphenylsulfonium chloride ([TPS][Cl]) with various acids in methanol yield the corresponding salts triphenylsulfonium triiodide, C₁₈H₁₅S⁺·I₃⁻or [TPS][I₃] (I), triphenylsulfonium perchlorate, C₁₈H₁₅S⁺·ClO₄⁻or [TPS][ClO₄] (II), and triphenylsulfonium hexafluorophosphate, C₁₈H₁₅S⁺·PF₆⁻or [TPS][PF₆] (III), as crystalline products. These crystals were structurally characterized by single-crystal X-ray diffraction. In all three compounds, the sulfur atom in the triphenylsulfonium cation adopts a distorted trigonal–pyramidal geometry. [TPS][I₃] (I) and [TPS][PF₆](III) both crystallize in the space groupP2₁/n, while [TPS][ClO₄] (II) crystallizes inP2₁. The S—C bond lengths are comparable across the three salts, and the S—C—S bond angles are consistently between 102 and 106°. Hirshfeld surface analyses reveal that each structure is dominated by hydrogen-based intermolecular contacts, supplemented by anion-specific interactions such as I...H in (I), O...H in (II), and F...H in (III). These contacts organize the ions into mono-periodic ribbon- or chain-like arrangements. No significant π–π stacking is observed. 

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4. A Hydride Migration Mechanism for the Mo‐Catalyzed Z ‐2‐Selective Isomerization of Terminal Alkenes

   https://doi.org/10.1002/cctc.202301052  

   Jenny, Sarah_E; Serviano, Juan_M; Nova, Ainara; Dobereiner, Graham_E (November 2023, ChemCatChem)

   Abstract The catalytic one‐bond isomerization (transposition) of 1‐alkenes is an emerging approach toZ‐2‐alkenes. Design of more selective catalysts would benefit from a mechanistic understanding of factors controllingZselectivity. We propose here a reaction pathway forcis‐Mo(CO)₄(PCy₃)(piperidine) (3), a precatalyst that shows highZselectivity for transposition of alpha olefins (e. g., 1‐octene to 2‐octene, 18 : 1Z : Eat 74 % conversion). Computational modeling of reaction pathways and isotopic labeling suggests the isomerization takes place via an allyl (1,3‐hydride shift) pathway, where oxidative addition offac‐(CO)₃Mo(PCy₃)(η²‐alkene) is followed by hydride migration from one position (cisto allyl C³carbon) to another (cisto allyl C¹carbon) via hydride/CO exchanges. Calculated barriers for the hydride migration pathway are lower than explored alternative mechanisms (e. g., change of allyl hapticity, allyl rotation). To our knowledge, this is the first study to propose such a hydride migration in alkene isomerization. 

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5. Syntheses and crystal structures of three triphenylsulfonium salts of manganese(II), iron(III) and cobalt(II)

   https://doi.org/10.1107/S2056989025006668  

   Callaway, Waylan; Elterman, Matthew; Krasilnikov, Nikita; Roberts, Gavin; Rutan, Davis; Spencer, Ty; Padgett, Clifford W; Lynch, Will E (August 2025, Acta Crystallographica Section E Crystallographic Communications)

   Bis(triphenylsulfonium) tetrachloridomanganate(II), (C₁₈H₁₅S)₂[MnCl₄] (I), triphenylsulfonium tetrachloridoferrate(III), (C₁₈H₁₅S)[FeCl₄] (II), and bis(triphenylsulfonium) tetrachloridocobaltate(II), (C₁₈H₁₅S)₂[CoCl₄] (III), crystallize in the monoclinic space groupsP2₁/n[(I) and (III)] andP2₁/c[(II)]. Compounds (I) and (III) each contain two crystallographically independent triphenylsulfonium (TPS⁺) cations in the asymmetric unit, whereas (II) has one. In all three compounds, the sulfonium centers adopt distorted trigonal–pyramidal geometries, with S—C bond lengths falling roughly in the 1.78–1.79 Å range and C—S—C angles observed at about 101 to 106°. The [MCl₄]ⁿ⁻anions (M= Mn²⁺, Fe³⁺, Co²⁺;n= 2,1,2) adopt slightly distorted tetrahedral geometries, withM—Cl bond lengths in the 2.19–2.38 Å range and Cl—M—Cl angles of approximately 104–113°. Hirshfeld surface analyses shows that H...H and H...C contacts dominate the TPS⁺cation environments, whereas H...Cl and shortM—S interactions link each [MCl₄]ⁿ⁻anion to the surrounding cations. In (I) and (III), inversion-centered π–π stacking further consolidates the crystal packing, while in (II) no π–π interactions are observed. 

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