Reductive debromination of {N(SiMe ) }SiBr with Rieke magnesium results in the formation of the five-vertex silicon cluster with one bromine substituent Si {N(SiMe ) } Br, 1, and the cyclobutadiene analogue 2 in a 1:1 ratio. The latter features a planar four-membered silicon ring with a charge-separated electronic situation. Two silicon atoms in 2 are trigonal planar and the other two trigonal pyramidal. In cycloadditions with ethylene, diethylacetylene, 1,5-cyclooctadiene, and 2,3-dimethyl-1,3-butadiene cyclic unsaturated ring compounds (3-6) were formed at room temperature in quantitative reactions. Two of the products (3 and 6) show photochemical isomerization with LED light (λ=405 nm) to afford saturated ring compounds 4 e and 6'.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8518912 | PMC |
http://dx.doi.org/10.1002/anie.202104341 | DOI Listing |
ACS Appl Mater Interfaces
December 2024
Department of Aerospace Engineering, Iowa State University, Ames, Iowa 50014, United States.
Using an interatomic potential that can capture the tetrahedral configuration of water molecules (HO) in ice without the need to explicitly track the motion of the O and H atoms, coarse-grained (CG) atomistic simulations are performed here to characterize the structures, energy, cohesive strengths, and fracture resistance of the grain boundaries (GBs) in polycrystalline ice resulting from water freezing. Taking the symmetric tilt grain boundaries (STGBs) with a tilting axis of ⟨0001⟩ as an example, several main findings from our simulations are (i) the GB energy, , exhibits a strong dependence on the GB misorientation angle, θ. The classical Read-Shockley model only predicts the - θ relation reasonably well when θ < 20° or θ > 45° but fails when 20° < θ < 45°; (ii) two "valleys" appear in the -θ landscape.
View Article and Find Full Text PDFCureus
November 2024
General Surgery, Centro Hospitalar Barreiro Montijo, Barreiro, PRT.
An enteroatmospheric fistula (EAF) is one of the most feared complications of damage control laparotomy. Its management is highly challenging, often requiring multiple surgeries and prolonged hospitalization. It is a serious condition, and despite significant improvements in mortality rates due to advancements in intensive care, the rate remains substantial.
View Article and Find Full Text PDFAdv Mater
December 2024
Institute of Physical Chemistry, Justus Liebig University Giessen, Heinrich-Buff-Ring 17, D-35392, Giessen, Germany.
Silicon is a promising negative electrode material for solid-state batteries (SSBs) due to its high specific capacity and ability to prevent lithium dendrite formation. However, SSBs with silicon electrodes currently suffer from poor cycling stability, despite chemical engineering efforts. This study investigates the cycling failure mechanism of composite Si/LiPSCl electrodes by decoupling the effects of interface chemical degradation and mechanical cracking.
View Article and Find Full Text PDFJ Hematol Oncol
December 2024
Experimentelle Unfallchirurgie (ForMED), Justus-Liebig-Universität Gießen, Aulweg 128, 35392, Gießen, Germany.
Background: Accumulation of malignant plasma cells in the bone marrow causes lytic bone lesions in 80% of multiple myeloma patients. Frequently fracturing, they are challenging to treat surgically. Myeloma cells surviving treatment in the presumably protective environment of bone lesions impede their healing by continued impact on bone turnover and can explain regular progression of patients without detectable minimal residual disease (MRD).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
State Key Laboratory of Low Carbon Catalysis and Carbon Dioxide Utilization, State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China.
Transition metal-catalyzed ring opening and expansion reactions of silacyclobutanes (SCBs) constitute an atom- and step-economical strategy to construct value-added silicon-containing chemicals. Despite extensive studies, the reaction of SCBs with simple alkenes has only one precedent. Moreover, most reported reactions of SCBs use late transition metals (Pd, Ni, Rh) as catalysts.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!