You selected: Wiley-VCH
Polymerization by chemical vapor deposition (CVD) is a simple method for modifying surfaces by which topologically challenging substrates can be evenly coated with polymers. In the journal Angewandte Chemie, researchers have now introduced the first CVD method for producing degradable polymers. Biomolecules or drugs can be attached by means of special side groups. This introduces new possibilities for applications like the coating of biodegradable implants.
Light Switch in Autumn Leaves: Yellow chlorophyll decomposition products are environment-responsive photoswitches
Before trees lose their leaves in the winter, they offer us a bright autumnal display of reds, oranges, and yellows. This results from the decomposition of the compound that makes leaves green: chlorophyll. Among the decomposition products are yellow phyllobilins that demonstrate unusual chemical properties. As reported by Austrian scientists in the journal Angewandte Chemie, these compounds act as four-step molecular “switches” that are triggered by light in different ways depending on the environment.
Implantable Catalyst Against Cancer: Biocompatible heterogeneous copper catalyst for click chemistry in living organisms
Assembling a drug from harmless components at the target location, such as a tumor, would help reduce the side effects of treatment. In the journal Angewandte Chemie, British and Malaysian scientists present a new, nontoxic catalyst made of copper nanoparticles that can be used to specifically and selectively assemble building blocks in a living system. It was shown to be possible to make an anti-tumor drug from two benign components in situ.
Safe Fog: Phosphorus nitride could be used as a friction-stable, fast-burning, and very effective pyrotechnic obscurant
Safety combined with power and effectiveness is one of the most important targets in the development of pyrotechnic obscurants. In the journal Angewandte Chemie, German and Polish scientists introduced phosphorus nitride as a safe but very powerful alternative to the well-known red phosphorus formulations, which have been used in military and civilian applications for decades.
Salty Batteries: Sodium-oxygen batteries have improved cycle life due to highly concentrated electrolytes
Smartphones, laptops, electric cars—whatever the device, an efficient battery is high on any user’s wish list. The search for the next-generation battery has recently focused on sodium– oxygen batteries. Theoretically, these should provide previously unattainable efficiency but their practical implementation has proven to be a stumbling block. Researchers now report in the journal Angewandte Chemie, that a highly concentrated electrolyte solution may make the sodium–oxygen battery more stable, and therefore more practicable.
Lithium Ion Extraction: A combined polymer/metal–organic composite membrane allows for the effective separation of lithium from contaminants in brines
The increasing usage of lithium for batteries or high-performance metals requires improved extraction techniques of lithium from primary sources such as salt lake brines. Chinese scientists have now designed a solid composite membrane that combines the mimicking of the chemical selection process in biological ion channels with molecular sieve technology. In the journal Angewandte Chemie, they report the effective and fast separation of lithium ions from brines with that membrane.
Fighting the Gram-Negatives: Natural products inspire the design of molecular agents against drug-resistant bacterial strains
Many microorganisms produce secondary natural products, the potential antibiotic effects of which are extensively investigated. German scientists have now examined a class of quinone-like substances containing an additional epoxide functional group for their antibiotic activities. As they report in the journal Angewandte Chemie, the compounds can kill problematic Salmonella pathogens, probably by interfering with their bacterial stress response system.
Directed motion seems simple to us, but the coordinated interplay of complex processes is needed, even for seemingly simple crawling motions of worms or snails. By using a gel that periodically swells and shrinks, researchers developed a model for the waves of muscular contraction and relaxation involved in crawling. As reported in the journal Angewandte Chemie, they were able to produce two types of crawling motion by using inhomogeneous irradiation.
Where Does Cisplatin Bind?: Identification of genome-wide cisplatin cross-linking sites with DNA base resolution
Cisplatin is one of the most widely used agents in cancer chemotherapy. Its mode of action is cross-linking of the DNA, which can kill cells. But which part of the genome is more affected, and which is less affected? A Chinese team of scientists have now set up a universal, genome-wide assay system to detect the specific cisplatin action sites, In the journal Angewandte Chemie the scientists introduce their system and report initial results, which support the notion that the mitochondrial genome is one of cisplatin's main targets.
Self-Healable Battery: Lithium ion battery for electronic textiles grows back together after breaking
Electronics that can be embedded in clothing are a growing trend. However, power sources remain a problem. In the journal Angewandte Chemie, scientists have now introduced thin, flexible, lithium ion batteries with self-healing properties that can be safely worn on the body. Even after completely breaking apart, the battery can grow back together without significant impact on its electrochemical properties.
Hidden Chirality: Nitrogen-15 isotope can trigger asymmetric autocatalytic reactions toward chiral organic compounds
The preparation of chiral compounds as intermediates in drug synthesis is one of the most important targets in synthetic organic chemistry. Japanese scientists have now shown that the autocatalytic preparation of a chiral intermediate can be triggered by a compound bearing hidden chirality, which consisted of nothing more than the difference between the isotopes nitrogen-15 and nitrogen-14. The study is published in the journal Angewandte Chemie.
Catalyst from the Microwave: Microwave-assisted thermolysis: New route to highly crystalline carbon nitrides for efficient photocatalytic hydrogen generation
Lunch out of the microwave usually doesn’t taste nearly as good as a meal made in a conventional oven. This difference in quality is reversed for graphitic carbon nitride, a catalyst used for generating hydrogen from sunlight. Treatment of a precursor material with microwaves delivers a significantly more crystalline product than conventional thermolysis in an oven. As scientists report in the journal Angewandte Chemie, a catalyst produced in this way is significantly more effective in the generation of hydrogen.
Body Heat as a Power Source: Wearable integrated thermocells based on gel electrolytes use body heat
Electronics integrated into textiles are gaining in popularity: Systems like smartphone displays in a sleeve or sensors to detect physical performance in athletic wear have already been produced. The main problem with these systems tends to be the lack of a comfortable, equally wearable source of power. Chinese scientists are now aiming to obtain the necessary energy from body heat. In the journal Angewandte Chemie, they have introduced a flexible, wearable thermocell based on two different gel electrolytes.
The recovery of gold and other noble metals from electronic waste, in particular discarded mobile phones, has enormous potential, but is still underdeveloped. British and American scientists have now identified a simple and nontoxic compound that is able to extract gold selectively from a mixture of metals that are usually present in such electronic waste. How this selective binding could be used in a convenient protocol for efficient gold recovery is described in the journal Angewandte Chemie.
How Did the Phosphate Get into RNA? Urea as one of the essential components in Darwin's "warm little pond"
The phosphate ion is almost insoluble and is one of the most inactive of Earth's most abundant phosphate minerals. So how could phosphate have originally been incorporated into ribonucleotides, the building blocks of RNA, which are considered to be among the earliest constituents of life? American and Spanish scientists have now identified reasonable conditions to mobilize phosphate from insoluble apatite minerals for prebiotic organophosphate synthesis, including ribonucleotides. The pivotal role of urea in this process is also described in their article in the journal Angewandte Chemie.
Cold-Fired Ceramics: Paradigm shift in ceramics production: cold sintering instead of high-temperature firing
Both hobbyists' pottery and engineered high-performance ceramics are only useable after they are fired for hours at high temperatures, usually above 1000 °C. The sintering process that takes place causes the individual particles to “bake” together, making the material more compact and giving it the required properties, like mechanical strength. In the journal Angewandte Chemie, American researchers have now demonstrated that sintering can also take place at significantly lower temperatures. This cold sintering process is based on the addition of small amounts of water to aid the key transport processes that densify the material.
Whether building bone, shells, or corals, living creatures are true masters of crystallization. In the laboratory, this amazing precision cannot be duplicated yet. The processes and many of the precise structures of bio minerals remain largely unexplored. In the journal Angewandte Chemie, an international team has now introduced a three-dimensional X-ray diffraction technique for determining crystallographic texture—the preferred orientation of the little crystals in a solid—with previously unattainable spatial resolution.
Rusty Steel Triggers Oxygen Evolution: Corroded stainless steel plate makes up an efficient water splitting electrode
Electrocatalytic water splitting is one of the most promising next generation technologies for environmentally friendly and inexpensive energy conversion and storage. However, one of its biggest obstacles is the sluggishness of the oxidation reaction, which is key to the whole process. State-of-the-art technology relies on metal oxide electrocatalysts, but both cost and performance still need to be improved. In the journal Angewandte Chemie, Chinese scientists have now introduced oxidized, that is, rusty, stainless-steel plates as excellent electrocatalysts for oxygen evolution. That technology could represent a surprisingly simple approach toward solving a long-standing problem.
Trinitrotoluene or TNT has been considered as the standard measure for explosives for 100 years, although new high-energy-density materials or HEDMs outperform this substance in terms of explosion power, safety, but also environmental compatibility. In the journal Angewandte Chemie, Russian scientists present the synthesis of a highly interesting HEDM, which exhibits excellent energetic properties as well as a beautiful, butterfly-like structure.
DNA polymerases are the “Xerox machines” that replicate our DNA. They must work with great precision to keep errors from creeping into our genes. In spite of this precision, they still accept building blocks that have been coupled to large proteins, as a group of German scientists reports in the journal Angewandte Chemie. Based on this fact, the team has developed detection systems for genotyping DNA and RNA that can be evaluated by the naked eye. This method may allow for new diagnostic tools for use in the field.