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In this work, ZnO2 was unexpectedly discovered as a friendly and renewable source of anhydrous hydrogen peroxide in the acid-catalyzed synthesis of cyclic organic peroxides from carbonyl compounds. In particular, five classes of cyclic organic peroxides, namely, γ-hydroperoxy-γ-peroxylactones, β-hydroperoxy-β-peroxylactones, bridged ozonides, bridged 1,2,4,5-tetraoxanes, tricyclic monoperoxides, and tricyclic diperoxides, were synthesized in good yields using in situ generated H2O2 from the reaction of ZnO2 with H2SO4. This approach is convenient, safe, and does not require a concentrated aqueous or ethereal solution of H2O2. The starting ZnO2 was synthesized from zinc acetate using a 1 wt% H2O2 solution. The reaction of zinc peroxide with sulfuric acid in an organic solvent results in the release of hydrogen peroxide and the formation of zinc sulfate, which acts as a desiccant by forming a monohydrate phase, ZnSO4·H2O. The possibility of recycling zinc peroxide from zinc sulfate monohydrate with a high yield was shown. [ABSTRACT FROM AUTHOR]

The halogen bonding in molecular crystals and supramolecular assemblies has been widely investigated. Special attention is given to the molecular structures capable of simultaneously exhibiting different types of non-covalent interactions, including conventional hydrogen bonds and halogen bonds. This paper systematically analyzes crystalline peroxosolvates of bispidine-based bis-amide derivatives, containing haloacetic acid residues, namely previously reported 1,1′-(1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-iodooethanone) peroxosolvate C13H20I2N2O2·H2O2 (1) and four new crystalline compounds, 1,1′-(1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-bromoethanone) peroxosolvate C13H20Br2N2O2·H2O2 (2), 1,1′-(9-hydroperoxy-9-hydroxy-1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-iodoethanone) peroxosolvate C13H20I2N2O5·0.5H2O2 (3), 1,1′-(9-hydroperoxy-9-hydroxy-1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-bromoethanone) peroxosolvate C13H20Br2N2O5·H2O2 (4), and 1,1′-(9-hydroperoxy-9-hydroxy-1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-chloroethanone) peroxosolvate C13H20Cl2N2O5·H2O2 (5). Compounds 2–5 were synthesized for the first time and their crystal structures were determined by single-crystal X-ray diffractometry (SCXRD). To the best of our knowledge, 3–5 are unprecedented crystalline hydrogen peroxide adducts of organic hydroperoxides (R-OOH). Short intermolecular contacts between halogen and hydroperoxo oxygen atoms were found in 1–3. The halogen bonding of C–I(Br) fragments with dioxygen species in compounds 1–3 as well as in the previously reported cocrystal of diacetone diperoxide with triodotrinitrobenzene (6) was identified through reduced density gradient analysis, Hirshfeld surface analysis, and Bader analysis of crystalline electron density. The interactions were quantified using the electron density topological properties acquired from the periodic DFT calculations and evaluated to lie in the range of 9–19 kJ mol−1. A distinctive spectral feature was revealed for this type of interaction, involving a red shift of the characteristic O–O stretching vibration by about 6 cm−1, which appeared in IR spectra as a narrow low-intensity band in the region 837–872 cm−1. [ABSTRACT FROM AUTHOR]

In recent years, metalloenzymes‐mediated highly selective oxidations of organic substrates under mild conditions have been inspiration for developing synthetic bioinspired catalyst systems, capable of conducting such processes in the laboratory (and, in the future, in industry), relying on easy‐to‐handle and environmentally benign oxidants such as H2O2. To date, non‐heme manganese complexes with chiral bis‐amino‐bis‐pyridylmethyl and structurally related ligands are considered as possessing the highest synthetic potential, having demonstrated the ability to mediate a variety of chemo‐ and stereoselective oxidative transformations, such as epoxidations, C(sp3)‐H hydroxylations and ketonizations, oxidative desymmetrizations, kinetic resolutions, etc. Furthermore, in the past few years non‐heme Mn based catalysts have become the major platform for studies focused on getting insight into the molecular mechanisms of oxidant activation and (stereo)selective oxygen transfer, testing non‐traditional hydroperoxide oxidants, engineering catalytic sites with enzyme‐like substrate recognition‐based selectivity, exploration of catalytic regioselectivity trends in the oxidation of biologically active substrates of natural origin. This contribution summarizes the progress in manganese catalyzed C‐H oxygenative transformations of organic substrates, achieved essentially in the past 5 years (late 2018–2023). [ABSTRACT FROM AUTHOR]

Zero-valent antimony and antimony oxide were deposited on graphene oxide by the recently introduced peroxide deposition route. The antimony@graphene oxide (GO) anode exhibits a charging capacity of 340 mAh g-1 with excellent stability at a current rate of 250 mA g-1 after 50 cycles of lithiation, which is superior to all other forms of antimony anodes that have been reported thus far. The electrode also exhibits a good rate performance, with a capacity of 230 and 180 mAh g-1 at a rate of 500 and 1000 mA g-1, respectively. We attribute the superior performance of the antimony@GO anodes to our coating protocol, which provides a thin layer of nanometric antimony coating on the graphene oxide, and to a small amount of antimony oxide that is left in the anode material after heat treatment and imparts some flexibility. The efficient charge distribution by the large surface area of reduced GO and the expansion buffering of the elastic graphene sheets also contributed to the superior stability of the anode.

Tellurates have attracted the attention of researchers over the past decade due to their properties and as less toxic forms of tellurium derivatives. However, the speciation of Te(VI) in aqueous solutions has not been comprehensively studied. We present a study of the equilibrium speciation of tellurates in aqueous solutions at a wide pH range, 2.5–15 by 17O, 123Te, and 125Te NMR spectroscopy. The coexistence of monomeric, dimeric, and trimeric oxidotellurate species in chemical equilibrium at a wide pH range has been shown. NMR spectroscopy, DFT computations, and single-crystal X-ray diffraction studies confirmed the formation and coexistence of trimeric tellurate anions with linear and triangular structures. Two cesium tellurates, Cs2[Te4O8(OH)10] and Cs2[Te2O4(OH)6], were isolated from the solution at pH 5.5 and 9.2, respectively, and studied by single-crystal X-ray diffractometry, revealing dimeric and tetrameric tellurate anions in corresponding crystal structures. [ABSTRACT FROM AUTHOR]

Potassium-ion batteries are attracting considerable attention as a viable type of high voltage battery. Among available anode materials, composites containing Sb2S3 are some of the most interesting high capacity candidates. A nanostructured Sb2S3–reduced graphene oxide composite anode material is evaluated in this study and compared with a structurally similar SnS2–reduced graphene oxide material reported previously by this team. The behaviour of the Sb2S3-based electrodes is assessed in both 1 M KPF6 in ethylene carbonate–diethyl carbonate and 1 M KPF6 in 1,2-dimethoxyethane electrolytes. Depotassiation capacities in excess of 650 mA h g−1 are recorded for the composite electrodes, superior not only to SnS2-based electrodes but also to all previously reported Sb2S3-containing electrode materials for potassium-ion batteries. In order to establish insights into the reaction mechanism of the Sb2S3 phase with potassium, post-cycling X-ray diffraction and in situ transmission electron microscopy are utilised. The recorded data suggest the presence of antimony alloys and potassium polysulphides as reaction products and intermediates; a possible conversion-alloying reaction mechanism is discussed. The results indicate that a capacity higher than previously believed is achievable in the Sb2S3 active component of potassium-ion battery electrodes. [ABSTRACT FROM AUTHOR]

The crystal structure of NH4+OOH- is determined from single-crystal x-ray data obtained at 150 K. The crystal belongs to the space group P21/c and has four molecules in a unit cell. The structure consists of discrete NH4+ and OOH- ions. The OOH- ions are linked by short hydrogen bonds (2.533 Å) to form parallel infinite chains. The ammonium ions form links between these chains (the N...O distances vary from 2.714 to 2.855 Å) giving a three-dimensional network. The harmonic IR spectrum and H-bond energies are computed at the Perdew-Burke-Ernzerhof (PBE)/6-31G** level with periodic boundary conditions. A detailed analysis of the shared (bridging) protons' dynamics is obtained from the CPMD simulations at different temperatures. PBE functional with plane-wave basis set (110 Ry) is used. At 10 K the shared proton sits near the oxygen atom, only a few proton jumps along the chain are detected at 70 K while at 270 K numerous proton jumps exist in the trajectory. The local-minimum structure of the space group Cc is localized. It appears as a result of proton transfer along a chain. This process is endothermic (∼2 kJ/mol) and is described as P21/c↔2Cc. The computed IR spectrum at 10 K is close to the harmonic one, the numerous bands appear at 70 K while at 270 K it shows a very broad absorption band that covers frequencies from about 1000 to 3000 cm-1. The advantages of the NH4+OOH- crystal as a promising model for the experimental and DFT based molecular dynamics simulation studies of proton transfer along the chain are discussed. [ABSTRACT FROM AUTHOR]