Tag Archives: Chemists

Chemists Incorporate Novel Carbon Homologs

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Carbon exists in various forms known as homologues, each with distinct properties including differences in color and shape. For instance, in diamond, every carbon atom is connected to four neighboring carbons, while in graphite, each carbon atom is bound to three others. The newly created molecule, Cyclo[48]Carbon, features 48 carbon atoms arranged in alternating single and triple bond patterns, exhibiting sufficient stability for spectroscopic characterization at room temperature in solution.

Chemical structure of cyclo[48]carbon [4]Catenan. Image credit: Harry Anderson.

Dr. Yuz Gao and his research team from Oxford University integrated cyclo.[48]Carbon molecules, creating a C48 ring that threads through three additional macrocycles.

These threaded macrocycles enhance the stability of the C48 by restricting access to the protected cyclocarbons.

Previously, molecular rings made entirely of carbon atoms have only been investigated in gas phase or at extremely low temperatures (4-10 K).

The researchers assert that Cyclo[48]Carbon maintains stability in a solution at 293 K (20 degrees Celsius).

This stability was achieved by utilizing threaded macrocycles, choosing larger cyclocarbons with low strain, and developing gentle reaction conditions for the non-masked step of the synthesis (where precursor molecules transform into the final product).

“Establishing stable cyclocarbons in vials under ambient conditions is a critical milestone,” stated Dr. Gao.

“This facilitates the examination of reactivity and characteristics under standard laboratory conditions.”

The team characterized the cyclocarbon catenene using a range of techniques including mass spectrometry, NMR, UV-visible, and Raman spectroscopy.

An intense observation of 13C NMR resonance for all 48 SP1 carbon atoms suggests that each carbon resides in a similar environment, strongly supporting the cyclocarbon catenene structure.

“The findings mark the pinnacle of our extensive efforts to synthesize cyclocarbon catenanes, based on the expectation that they may be stable enough for studies at room temperature,” remarked Professor Andersen.

The team’s research was published in the journal Science.

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Yuze Gao et al. 2025. Solution phase stabilization of cyclocarbons by catenene layers. Science 389 (6761): 708-710; doi: 10.1126/science.ady6054

Source: www.sci.news

Chemists Uncover “Anchapis” That Enhances Chili Pepper Heat

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Piri Piri or African Bird’s Eye Chilli Peppers

Steidi/Alamy

Have you ever made your food too spicy? In the future, there might be “anti-spice” seasonings, inspired by compounds in chili peppers that could help mellow the heat.

The spiciness in chili peppers is due to a compound called capsaicinoids, which activate receptors in the mouth’s nerve fibers, sending signals to the brain that create a burning sensation similar to that of actual heat or painful injuries.

Chilean enthusiasts have developed a Scoville scale to measure the heat levels in various pepper strains based on capsaicinoid concentrations. However, some peppers do not always match their Scoville ratings accurately. To explore this, Devin Peterson from Ohio State University and his team employed liquid chromatography mass spectrometry to analyze the capsaicin and dihydrocapsaicin levels in 10 different chili powders, including Chile de árbol, African bird’s eye, and Scottish bonnet peppers.

They then mixed these powders with tomato juice and presented it to a panel of tasters, ensuring each sample had equal amounts of capsaicin and dihydrocapsaicin, expected to yield a mild heat level of about 800 Scoville units.

However, the tasters perceived the heat levels differently among the 10 types of peppers. This led Peterson and his team to conduct further chemical analyses, revealing that three compounds—capsianoside I, balasoside, and ginger glycolipid A—were present in larger quantities. Interestingly, these compounds did not exhibit the expected heat intensity according to Scoville ratings. All three compounds contain glucosides and glucose.

A group of 37 tasters was then asked to evaluate two samples simultaneously. One sample contained these newly discovered compounds, while the other did not. The placement of each on different sides of the tongue was intended to counteract the burning sensation in the second taste test. The feedback indicated that these compounds reduced perceived heat strength by an average of 0.7 to 1.2 points on a 15-point scale.

“These compounds act as effective ‘anti-spicing’ agents,” Peterson notes. Although the exact mechanism remains unclear, it’s hypothesized that they could alter the nerve receptor responses in the mouth, thereby diminishing the burning sensations.

Understanding the nature of these anti-spice chemicals could enable growers to breed and genetically modify plants, nurturing varieties that produce both fiery and mild fruits.

Peterson believes that utilizing these compounds could lead to the development of consumer products that alleviate excessive heat in dishes, offering relief from intense pain by blocking nerve signals.

“When dining with kids, if the food is too spicy, it can be a deal-breaker,” Peterson says. “The idea of having a natural compound to dial down the heat could be quite intriguing.”

The research methodology, which involved half-tasting, was praised by Barry Smith from the University of London’s Advanced Research School, who added that the Scoville scale isn’t always the most accurate tool for measuring chili heat.

Smith speculates that the perceived intensity of cooling agents like menthol might similarly be diminished by such compounds, much like how capsaicinoids trigger a burning sensation.

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Source: www.newscientist.com

Bakeromene: Chemists Synthesize Barium-Containing Organometallic Molecules

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Organometallic molecules are made up of metal ions surrounded by a carbon-based framework. They are relatively common in early actinide elements such as uranium, but are little known in later actinides. Scientists at the Lawrence Berkeley National Laboratory (Berkeley Lab) are currently preparing an organometallic complex from 0.3 milligrams of bacherium 249.

The purple/blue solution in this vial contains Barcheromene crystals. Image credit: Alyssa Gaiser/Berkeley Lab.

Barcrium, one of the 15 actinides in the F block of the periodic table, was discovered in 1949 by pioneering nuclear chemist Glenn Sieborg.

However, this heavy element is very radioactive and not easy to study. And only very small quantities of the products produced globally each year are produced.

Dr. Stephen Minasian, a scientist at the Berkeley Institute, said:

“This finding provides a new understanding of how burcrium and other actinides behave towards their periodic table peers.”

“A small number of facilities around the world can protect both compounds and workers while managing the risk of highly radioactive materials that react vigorously with oxygen and moisture in the air,” added Professor Poly Arnold, a chemist at the University of California, Berkeley and director of the Chemistry Sciences at Berkeley Lab.

At Berkeley Lab’s Heavy Element Research Laboratory, researchers designed a new glovebox that uses highly radioactive isotopes to allow for lethargic synths.

They then performed single crystal X-ray diffraction experiments with just 0.3 milligrams of Vercrium-249.

The results showed a symmetrical structure with a barcrium atoms sandwiched between two 8-membered carbon rings.

Scientists have named the new molecular Bacheromene because its structure is similar to a uranium organometallic complex called Uranosene.

An unexpected discovery revealed that electronic structure calculations revealed that the bacherium atom at the center of the Balkeracene structure has a quadruple oxidation state (positive charge of +4) stabilized by the barkerium carbon bond.

“The traditional understanding of the periodic table suggests that bacherium behaves like lanthanide terbium,” Dr. Minasian said.

“But Barcrium ions are much happier in the +4 oxidation state than the other F-block ions we expected to be the most similar,” Professor Arnold added.

“A more accurate model showing how actinide behavior changes are needed across the periodic table to solve problems related to long-term nuclear waste storage and repair.”

“This clear portrait of actinides like the barklium provides a new lens for the behavior of these fascinating elements,” says Dr. Rebecca Abelgel, a researcher at Berkeley Lab and the University of California, Berkeley.

a paper The explanation of this study was published in the journal Science.

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Dominic R. Russo et al. 2025. Barcrium carbon bonds in quadruple Berkeromene. Science 387 (6737): 974-978; doi: 10.1126/science.adr3346

Source: www.sci.news

Chemists show the existence of sulfurous acid in the gas phase in normal atmospheric conditions

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Chemists at the Leibniz Institute for Tropospheric Research have discovered that sulfurous acid (H2So3), once formed in the gas phase, is kinetically stable enough to allow its characterization and subsequent reactions.

In the gas phase, sulfurous acid, once formed, exhibits some kinetic stability with a lifetime of at least 1 second in atmospheric water vapor conditions. Image courtesy of Berndt others., doi:10.1002/anie.202405572.

Sulfurous acid Having formula H2So3 The molecular weight is 82.075 g/mol.

This molecule, also known as sulfuric acid(IV) or thioic acid, is a difficult-to-reach acid that has never before been observed in aqueous solution.

However, sulfite Detected It was discovered in the gas phase in 1988 by dissociative ionization of diethyl sulfite.

“The only experimental detection of sulfurous acid to date was achieved in 1988 by the team of Helmut Schwarz at the Technical University of Berlin using in situ generation with a mass spectrometer,” said Dr. Torsten Berndt of the Leibniz Institute for Tropospheric Research and colleagues.

“Under vacuum conditions, we estimated an extremely short lifetime of more than 10 microseconds.”

“Theoretical calculations show that H2So3 As a possible reaction product of the gas-phase reaction of OH radicals with dimethyl sulfide (DMS), which are produced from ozone and water molecules in the troposphere primarily in the presence of ultraviolet light.”

“DMS is produced primarily by biological processes in the ocean and is the largest source of biogenic sulfur in the atmosphere, producing approximately 30 million tonnes per year.”

The researchers experimentally investigated possible reaction pathways to H.2So3 It starts with DMS.

Formation of H2So3 Its formation in the gas phase was clearly demonstrated in a flow reactor under atmospheric conditions.

“Under our experimental conditions, sulfurous acid remained stable for 30 seconds, regardless of humidity,” the researchers said.

“With the existing experimental setup, longer residence times have not yet been explored.”

“Therefore, H2So3 It may persist in the atmosphere long enough to affect chemical reactions.”

“The observed yields were somewhat higher than theoretically expected.”

According to related model simulations, about 8 million tons of H2So3 They form every year all over the world.

“In this pathway, the mass of H increases by about 200 times.2So3 Sulfuric acid (H2So4“It produces carbon dioxide (CO2) from dimethyl sulfide in the atmosphere,” said Dr Andreas Tilgner and Dr Eric Hofmann from the Leibniz Institute for Tropospheric Research.

“The new results may contribute to a better understanding of the atmospheric sulfur cycle.”

Team paper Published in the journal Applied Chemistry.

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Torsten Berndt others2024. Gas-phase production of sulfurous acid (H)2So3) floats in the atmosphere. Applied Chemistry 63(30):e202405572;doi:10.1002/anie.202405572

Source: www.sci.news

Chemists at MIT create vibrant organic molecules through synthesis

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Researchers at MIT have made a groundbreaking development in the stability of acene, a molecule with potential for use in semiconductors and light-emitting diodes. This advancement has opened up possibilities for acene to emit light in a range of colors, leading to its potential use in solar cells and energy-efficient screens. Known as organic light-emitting diodes and promising for use in solar cells, acenes consist of chains of fused carbon-containing rings with unique optoelectronic properties.

However, the stability of acene has been challenging, as the length of the molecule determines the color of light it emits, and longer acenes tend to be less stable and therefore not widely used in light-emitting applications. Researchers at MIT have devised a new approach to address this issue, making the molecules more stable in order to synthesize acenes of various lengths and build molecules that emit red, orange, yellow, green, or blue light. This innovative approach allowed them to create acenes with positive charges that possess increased stability and unique electronic properties, making them suitable for a wide range of applications.

The new, stable acenes, doped with boron and nitrogen, can now emit light in different colors depending on their length and the type of chemical group attached to the carbodicarbene. This is a significant development, as traditional acene molecules tend to emit only blue light, while the ability to emit red light is vital for many applications, including biological processes such as imaging. The new acenes also exhibit stability in both air and water, a noteworthy feature that opens up possibilities for medical applications.

Furthermore, researchers are exploring the potential of acenes in various derivative forms and incorporating them into technologies such as solar cells and light-emitting diodes for use in screens. By combining creative research with non-traditional paradigms, the research holds promising implications for the development of air- and photostable luminescent materials and compact energy harvesting devices. This innovative work was supported by the Arnold and Mabel Beckman Foundation and the National Science Foundation’s Major Research Instrumentation Program.

Source: scitechdaily.com