A facile synthesis of bromodifluoromethylated selenides under metal-free conditions is described here. Commercially available Me
SiCF
Br and bench-stable selenosulfonates react smoothly to give a ...broad scope of alkyl- and aryl-substituted bromodifluoromethylated selenides in moderate to good yields via a difluorocarbene intermediate. This protocol features a short reaction time, the absence of toxic waste, good scalability, and successful late-stage modification of bioactive molecules. In addition, the title products can be easily converted to different fluorinated and
F-labeled selenides.
The ungenerous release of metals from different industrial, agricultural, and anthropogenic sources has resulted in heavy metal pollution. Metals with a density larger than 5 g cm
−3
have been termed ...as heavy metals and have been stated to be potentially toxic to human and animals. Algae are known to be pioneer organisms with the potential to grow under extreme conditions including heavy metal-polluted sites. They have evolved efficient defense strategies to combat the toxic effects exerted by heavy metal ions. Most of the algal strains are reported to accumulate elevated metal ion concentration in cellular organelles. With respect to that, this review focuses on understanding the various strategies used by algal system for heavy metal resistance. Additionally, the application of this metal resistance in biosynthesis of metal nanoparticles and metal oxide nanoparticles has been investigated in details. We thereby conclude that algae serve as an excellent system for understanding metal uptake and accumulation. This thereby assists in the design and development of low-cost approaches for large-scale synthesis of nanoparticles and bioremediation approach, providing ample opportunities for future work.
As green solvents, ionic liquids (ILs) can be substitutes for traditional organic solvents, and form useful microemulsions with water. Microemulsions consisting of the IL, 1-butyl-3-methylimidazolium ...hexafluorophosphate (bmimPF), the non-ionic surfactant Tween 20 and water were formed at 30.0 degreeC, and the phase behavior of the ternary system was investigated. Three regions of the microemulsions: water-in-bmimPF (W/IL), bicontinuous, and bmimPF-in-water (IL/W) were identified by cyclic voltammetry using potassium ferrocyanide KFe(CN) as an electroactive probe. The polarity of the microemulsion environment was investigated by UV-Visible spectroscopy using methyl orange as a probe. Use of the ionic compound KFe(CN) in UV-Visible measurements revealed that the bmimPF/Tween 20/HO microemulsions could solubilize salt species into the microemulsion droplets. Moreover, the solubilization of riboflavin in the microemulsions was also shown by UV-Visible spectra. These results show that these IL-based microemulsions have potential in the production of metal nanomaterials, in biological extractions or as solvents for enzymatic reactions.
Rare Earth Frontiers is a work of human geography that serves to demystify the powerful elements that make possible the miniaturization of electronics, green energy and medical technologies, and ...essential telecommunications and defense systems. Julie Michelle Klinger draws attention to the fact that the rare earths we rely on most are as common as copper or lead, and this means the implications of their extraction are global. Klinger excavates the rich historical origins and ongoing ramifications of the quest to mine rare earths in ever more impossible places. Klinger writes about the devastating damage to lives and the environment caused by the exploitation of rare earths. She demonstrates in human terms how scarcity myths have been conscripted into diverse geopolitical campaigns that use rare earth mining as a pretext to capture spaces that have historically fallen beyond the grasp of centralized power. These include legally and logistically forbidding locations in the Amazon, Greenland, and Afghanistan, and on the Moon. Drawing on ethnographic, archival, and interview data gathered in local languages and offering possible solutions to the problems it documents, this book examines the production of the rare earth frontier as a place, a concept, and a zone of contestation, sacrifice, and transformation.
The cover image is based on the Original Article Characteristics, distribution, and children exposure assessment of 13 metals in household dust in China: A big data pilot study by Xu Li et al., ...https://doi.org/10.1111/ina.12943.
Understanding the thermal aggregation behavior of metal atoms is important for the synthesis of supported metal clusters. Here, derived from a metal–organic framework encapsulating a trinuclear ...FeIII2FeII complex (denoted as Fe3) within the channels, a well‐defined nitrogen‐doped carbon layer is fabricated as an ideal support for stabilizing the generated iron nanoclusters. Atomic replacement of FeII by other metal(II) ions (e.g., ZnII/CoII) via synthesizing isostructural trinuclear‐complex precursors (Fe2Zn/Fe2Co), namely the “heteroatom modulator approach”, is inhibiting the aggregation of Fe atoms toward nanoclusters with formation of a stable iron dimer in an optimal metal–nitrogen moiety, clearly identified by direct transmission electron microscopy and X‐ray absorption fine structure analysis. The supported iron dimer, serving as cooperative metal–metal site, acts as efficient oxygen evolution catalyst. Our findings offer an atomic insight to guide the future design of ultrasmall metal clusters bearing outstanding catalytic capabilities.
Encapsulation of a trinuclear FeIII2FeII complex within channels of a unique MOF is leading to the generation of iron nanoclusters stabilized on the carbon layer. To inhibit the aggregation of iron atoms toward nanoclusters, a “heteroatom modulator approach” is developed by atomic replacement of FeII by ZnII/CoII. A stable iron dimer in an optimal metal–nitrogen moiety is synthesized as efficient oxygen evolution catalyst.
Creep refers to the slow, permanent deformation of materials under external loads, or stresses. It explains the creep strength or resistance to this extension. This book is for experts in the field ...of strength of metals, alloys and ceramics. It explains creep behavior at the atomic or "dislocation defect" level. This book has many illustrations and many references. The figure formats are uniform and consistently labeled for increased readability. This Second Edition updates and improves the previous edition.
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