X-ray powder diffraction features of manganites DyM 3I M 3II Mn4O12 (MI = Li, Na, K; MII = Mg, Ba)

Manganites DyM₃^IMg₃Mn₄O₁₂ and DyM₃^IBa₃Mn₄O₁₂ (M^I = Li, Na, K) were synthesized by the solid-state reaction of dysprosium and manganese(III) oxides and magnesium and corresponding alkali metal carbonates. The X-ray powder diffraction studies showed that the crystals are orthozhombic with the following unit cell parameters and densities: DyLi₃Mg₃Mn₄O₁₂—a = 10.88 ?, b = 10.73 ?, c = 19.63 ?, V ⁰ = 1656.2 ?³, Z = 8, ρ_calc = 5.36 g/cm³, ρ_pycn = 5.11 ± 0.05 g/cm³; DyNaMg₃Mn₄O₁₂—a = 10.55 ?, b = 10.72 ?, c = 18.28 ?, V ⁰ = 2067.4 ?³, Z = 8, ρ_calc = 4.60 g/cm³, ρ_pycn = 4.88 ± 0.09 g/cm³; DyK₃Mg₃Mn₄O₁₂—a = 10.56 ?, b = 10.72 ?, c = 20.89 ?, V ⁰ = 2206.0 ?³, Z = 8, ρ_calc = 4.60 g/cm³, ρ_pycn = 4.92 ± 0.06 g/cm³; DyLi₃Ba₃Mn₄O₁₂—a = 10.53 ?, b = 10.69 ?, c = 21.28 ?, V ⁰ = 2395.4 ?³, Z = 8, ρ_calc = 5.58 g/cm³, ρ_pycn = 5.98 ± 0.12 g/cm³; DyNa₃Ba₃Mn₄O₁₂—a = 10.53 ?, b = 10.74 ?, c = 23.00 ?, V ⁰ = 2602.3 ?³, Z = 8, ρ_calc = 5.39 g/cm³, ρ_pycn = 5.30 ± 0.07 g/cm³; DyK₃Ba₃Mn₄O₁₂—a = 10.52 ?, b = 10.75 ?, c = 25.69 ?, V ⁰ = 2905.2 ?³, Z = 8, ρ_calc = 5.04 g/cm³, ρ_pycn = 5.00 ± 0.18 g/cm³.     

New “s<Emphasis Type="Italic">p</Emphasis><Superscript><Emphasis Type="Italic">2</Emphasis></Superscript>-bonded” carbanucleosides

By reaction of 2,3-dichloro-, 2,3,5-trichloro-, 2,5-dichloro-3-phenylsulfonyl-, 2-chloro-3-phenylsulfonyl-4,4-ethylenedioxycyclopent-2-en-1-ones with uracyl 3- and 2-uracyl derivatives were obtained of the corresponding chlorocyclopentenone.     

Nd[Al(iPrO)4]3, a novel tetranuclear alkoxide forming merohedrally twinned crystals

The new tetranuclear alkoxide hexa‐μ₂‐isopropoxy‐1:2κ⁴O;1:3κ⁴O;1:4κ⁴O‐hexaisopropoxy‐2κ²O,3κ²O,4κ²O‐trialumin­ium(III)­neodymium(III), [Nd{Al(C₃H₇O)₄}₃], has a metal–oxy­gen NdAl₃O₁₂ core which consists of four metal atoms arranged in an approximately planar triangular geometry. The central Nd atom is six‐coordinated by O atoms and the Al atoms are four‐coordinated by O atoms.     

Real‐Time Scanning Force Microscopy of Macromolecular Conformational Transitions

Summary: Comb‐like macromolecules were adsorbed on mica and imaged by scanning force microscopy in real time as they underwent a transition from an extended worm‐like conformation to globuli and vice versa. The conformational transition was effected by coadsorption of ethanol and water molecules. Coadsorption of the small molecules allowed manipulation of the adherence and spreading of the macromolecules, thus effecting the reptation like stretching and collapse of the single molecules.

SFM images of three individual PMA‐g‐PnBuA brush molecules on mica 27 min (left, first collapse cycle) and 18 min (right, second collapse cycle) after injection of ethanol into the sample space.     

Toward extracting $$\gamma $$ from $$B\rightarrow DK$$ without binning

SABRE (Sodium iodide with Active Background REjection) is a direct detection dark matter experiment based on arrays of radio-pure NaI(Tl) crystals. The experiment aims at achieving an ultra-low background rate and its primary goal is to confirm or refute the results from the DAMA/LIBRA experiment. The SABRE Proof-of-Principle phase was carried out in 2020–2021 at the Gran Sasso National Laboratory (LNGS), in Italy. The next phase consists of two full-scale experiments: SABRE South at the Stawell Underground Physics Laboratory, in Australia, and SABRE North at LNGS. This paper focuses on SABRE South and presents a detailed simulation of the detector, which is used to characterise the background for dark matter searches including DAMA/LIBRA-like modulation. We estimate an overall background of 0.72 cpd/kg/\(\hbox {keV}_{\hbox {{ee}}}\) in the energy range 1–6 \(\hbox {keV}_{\hbox {{ee}}}\) primarily due to radioactive contamination in the crystals. Given this level of background and considering that the SABRE South has a target mass of 50 kg, we expect to exclude (confirm) DAMA/LIBRA modulation at \(4~(5)\sigma \) within 2.5 years of data taking.

     

Synthesis of Complex Thiazoline-Containing Peptides by Cyclodesulfhydration of N-Thioacyl-2-Mercaptoethylamine Derivatives

Herein we report a mild, efficient, and epimerization-free method for the synthesis of peptide-derived 2-thiazolines and 5,6-dihydro-4H-1,3-thiazines based on a cyclodesulfhydration of N-thioacyl-2-mercaptoethylamine or N-thioacyl-3-mercaptopropylamine derivatives. The described reaction can be easily carried out in aqueous solutions at room temperature and it is triggered by change of the pH, leading to complex thiazoline or dihydrothiazine derivatives without epimerization in excellent to quantitative yields. The new method was applied in the total synthesis of the marine metabolite mollamide F, resulting in the revision of its stereochemistry.