Solving an 80-year-old mystery: the crystal structure of a tetra-n-butylammonium bromide hydrate found with synchrotron radiation

Yokohama National University

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Although occupation of dodecahedral cages by TBAB had not been previously reported, it was found that utilizing dodecahedral cages allows for higher packing density of TBAB.

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Credit: YOKOHAMA National University

Researchers have solved a mystery that has confounded scientists for 80 years: the crystal structure of the tetra-n-butylammonium bromide (TBAB) hydrate TBAB·26H2O. This substance belongs to a class of crystalline materials called semiclathrate hydrates, which form from the combination of ions and water. Since its discovery in 1940, this TBAB hydrate has been widely used in a range of applications, including air conditioning. Understanding the crystal structure of this important semiclathrate hydrate will help scientists and engineers better utilize TBAB hydrate.

The results were shared in a paper published in Crystal Growth & Design on July 17 .

“For 80 years, the crystal structure of the widely used TBAB hydrate (TBAB·26H2O) remained unresolved, despite its importance in thermal energy storage applications. This structural ambiguity hindered both scientific understanding and practical optimization of the material. Our goal was to definitively determine the structure using synchrotron radiation and clarify its molecular arrangement,” said Sanehiro Muromachi, an associate professor at YOKOHAMA National University in Yokohama, Japan and Hironobu Machida, Chief Engineer at Panasonic Corporation in Osaka, Japan.

Water-based functional materials—including hydrogels, aqueous polymers, liquid crystals, and clathrate hydrates—take advantage of the unique properties of water and are used in a variety of industrial processes. Water is abundant and sustainable, making these an important part of sustainable industrial processes. TBAB·26H2O is a semiclathrate hydrate that can store cool energy at temperatures suitable for air conditioning applications. It is made of a guest molecule of TBAB surrounded by a hydrogen-bonded cage of water molecules. While other semiclathrate hydrates with a TBAB guest molecule have had their structures uncovered, the crystal structure of TBAB·26H2O has remained a mystery despite its wide use. Previous research suggested a tetragonal lattice structure, but this could not fully explain all of the properties of TBAB·26H2O.

Researchers used a synchrotron radiation facility called the Super Photon ring-8, or SPring-8 in Sayo Town, Japan. During synchrotron radiation, charged particles travel along a curved path and release electromagnetic radiation. The structure of the TBAB tetragonal hydrate was a Jeffrey’s type III hydrate structure, one of the known types, but with unique features. It has a composition identical to those found in another TBA semiclathrate hydrate called TBA(NO3), but with a different arrangement resulting in a denser crystal.

Understanding this new structure reveals heat storage properties of TBAB·26H2O, which can be applied to a variety of practical applications. In particular, it introduces new options for designing heat storage materials based on hydrates. This is an important finding that can help reduce CO2 emissions.

“We successfully resolved the crystal structure of TBAB·26H2O for the first time, revealing a unique tetragonal superstructure that accommodates the TBA cation in a novel cage configuration.”, said Muromachi. “This structure explains the material’s heat storage characteristics and provides new design principles for hydrate-based functional materials. Understanding this structure opens the door to engineering better thermal storage and related applications,” said Machida.

Looking ahead, researchers plan to use this new understanding of the crystal structure of the TBAB hydrate to create advanced water-based materials and contribute to energy-efficient technologies, such as air conditioning, gas separation, and carbon capture. “The next step is to apply this structural knowledge and seek to expand these structural principles to other hydrate-forming systems, including polymers and soft matter,” said Muromachi.

Other contributors include Nobuhiro Yasuda and Hiroyasu Masunaga of the Japan Synchotron Radiation Research Institute (JASRI); Takeshi Sugahara of The University of Osaka; and Hironobu Machida of the Panasonic Corporation.

The Thermal Management Materials and Technology Research Association (TherMAT) project (JPNP15007) at the New Energy and Industrial Technology Development Organization (NEDO) supported this research.

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YOKOHAMA National University (YNU) is a leading research university dedicated to academic excellence and global collaboration. Its faculties and research institutes lead efforts in pioneering new academic fields, advancing research in artificial intelligence, robotics, quantum information, semiconductor innovation, energy, biotechnology, ecosystems, and smart city development. Through interdisciplinary research and international partnerships, YNU drives innovation and contributes to global societal advancement.

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Journal

Crystal Growth & Design

DOI

10.1021/acs.cgd.5c00364 

Article Title

Solving the 80-Year Structure Mystery: Definitive Crystal Structure of TBAB Hydrate Resolved with Synchrotron Radiation

Article Publication Date

17-Jul-2025

 

Complete pollutant removal in minutes: Cobalt-tuned ferroelectrics offer rapid water cleanup

Higher Education Press

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The bioinspired intracrystalline force regulation strategy for enhanced piezocatalytic degradation of organic pollutants.

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Credit: Central South University

Many conventional methods for cleaning polluted water rely on chemical reactions analogous to the action of bleach. Among these, Fenton-like processes are gaining prominence due to their effectiveness in breaking down harmful pollutants. Cobalt plays a crucial role in these reactions, acting as a catalyst to drive the cleaning process. However, cobalt's activity can diminish over time, requiring constant "re-fueling" to sustain its cleaning power. Unfortunately, this "re-fueling" process is often a bottleneck, limiting the overall speed of water purification.

Inspired by the drag-reducing adaptations of fish scales, we developed a novel strategy harnessing mechanical stimuli to generate an "internal force" within a cobalt-containing ferroelectric material. This "internal force" functions as a miniature, integrated power source, continuously regenerating the highly active, high-spin state of cobalt – effectively "re-energizing" the catalyst. Leveraging this internal force to precisely regulate the electronic configuration of cobalt ions, we achieve the rapid production of potent cleaning agents, enabling complete removal of the model pollutant Rhodamine B within a mere 2.5 minutes.

This research opens up exciting new possibilities for creating more sustainable and economical water treatment systems. This innovative approach, inspired by the natural world, could revolutionize the design of next-generation "green" cleaning technologies. The work titled “Ultrafast Piezocatalytic Organic Pollutant Degradation Enabled by Dynamic Spin State Regulation of Cobalt in Nano-Ferroelectrics” was published on Advanced Powder Materials (available online on Jun. 14, 2025).

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Journal

Advanced Powder Materials

DOI

10.1016/j.apmate.2025.100307 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Ultrafast piezocatalytic organic pollutant degradation enabled by dynamic spin state regulation of cobalt in nano-ferroelectrics

Article Publication Date

24-Jun-2025

 

Earth's future climate at 9 km worldwide resolution

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Institute for Basic Science

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A snapshot of simulated climate conditions. Blue/red shading: sea surface temperature deviations from zonal mean; gray/white shading: low clouds; green/pink shading: 10m wind speed; blue/yellow shading in upper panels: hurricane precipitation. The figure illustrates the ubiquity of mesoscale climate phenomena, such as Tropical Instability Waves in the equatorial Atlantic and Pacific, hurricanes (making landfall in Hawaiʻi in this snapshot), ocean cold wakes generated by hurricanes, stratocumulus cloud decks and patchy day-time convection over the Amazon forest.

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Credit: Institute for Basic Science

Global Warming does not affect our planet evenly. Some areas such as the Arctic region or high mountain peaks warm faster than the global average, whereas others, including large parts of the tropical oceans, show reduced temperature trends compared to the mean. The heterogeneity of future rainfall patterns is even more pronounced. To adapt to future climate change, policymakers and stakeholders need detailed regional climate information, often on scales much smaller than the typical resolution (~100-200 km) of climate models used in the reports of the Intergovernmental Panel on Climate Change (IPCC).

A team of scientists from the IBS Center for Climate Physics (ICCP), Pusan National University in South Korea and the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), Bremerhaven, Germany has achieved an important breakthrough in climate modeling, providing unprecedented insights into Earth's future climate and its variability. Their research was published in the open access journal Earth System Dynamics.

Utilizing the AWI-CM3 earth system model, a novel iterative global modeling protocol, and two of South Korea's fastest supercomputers (Aleph at the Institute for Basic Science and Guru at the Korea Meteorological Administration), the researchers have simulated climate change at scales of 9 km in the atmosphere and 4-25 km in the ocean. These extensive computer model simulations offer a more accurate representation of future climate conditions, enabling better planning for climate adaptation.

The AWI-CM3 high-resolution model accurately represents global climate, including small-scale phenomena, such as rainfall in mountainous regions, coastal and island climate processes, hurricanes and ocean turbulence (Fig. 1). By resolving more regional details and their interactions with the large-scale atmosphere and ocean circulations, the model demonstrates a superior performance compared to most lower-resolution climate models.

A main product of the simulations is a set of detailed global maps of expected climate change (e.g., temperature, rainfall, winds, ocean currents, etc.) for an anticipated 1oC future global warming.

"It is important to keep in mind that Global Warming is spatially quite heterogenous. For a 1oC global temperature increase, the Siberian and Canadian Arctic will warm by about 2oC, whereas the Arctic Ocean will experience warming of up to 5oC. In high mountain regions, such as the Himalayas, the Andes and the Hindu Kush, the model simulates a 45-60% acceleration relative to the global mean", says MOON Ja-Yeon from the ICCP, and lead author of the study. To ensure broad access to these high-resolution climate projections, the team has launched an interactive data platform, where users can explore future climate change on regional and global scales (Fig. 2). Normalized climate change data for a 1°C Global Warming level can be downloaded and opened directly in the Google Earth application. These data can provide information on expected future changes in climate variables, such as windspeed and clouds, which are relevant for the future deployment of wind or solar farms, respectively.

"Our study also highlights the regional impacts of major modes of climate variability, such as the Madden Julian Oscillation, the North Atlantic Oscillation, and the El Niño-Southern Oscillation, as well as their response to greenhouse warming" says Prof. Thomas JUNG from the AWI and co-corresponding author of the study. According to the AWI-CM3 simulations, the amplitude of both, the Madden Julian Oscillation and of the alternating El Niño and La Niña events will increase in the future, which will lead to intensified rainfall impacts in affected regions. ​The simulations further indicate an increase in the frequency and intensity of extreme rainfall events (>50 mm/day) in areas such as eastern Asia, the Himalayas, the Andes, Amazonia, mountain-tops in Africa and the east coast of North America with significant implications for flooding, erosion, and landslides.

"Most global climate models used in the assessment reports of the IPCC are too coarse to resolve small islands, such as those in the western tropical Pacific. These islands are already threatened by global sea level rise. Our new climate model simulations now provide new regional insights into what these regions can expect in terms of changes in ocean currents, temperatures, rainfall patterns and weather extremes. We hope that our dataset will be used extensively by planners, policy- and decision-makers and the public.", says Prof. Axel TIMMERMANN, Director of the ICCP and co-corresponding author of the study.

The study's findings offer critical information for assessing climate risks and implementing adaptation measures on regional scales.

 

Download data of climate change (e.g., temperature, wind speed, precipitation, etc.) per 1oC global warming from 9 km AWI-CM3 Global Warming simulations. Go to: https://climatedata.ibs.re.kr/data/papers/moon-et-al-2024-earth-system-dynamics.

Credit

Institute for Basic Science

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Journal

Earth System Dynamics

DOI

10.5194/esd-16-1103-2025 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Earth’s Future climate and its variability simulated at 9 km global resolution

Article Publication Date

17-Jul-2025

 

Between hype and misconception: common misunderstandings about food supplements

The new issue of the BfR2GO Science Magazine, with a focus on food supplements, has been released

BfR Federal Institute for Risk Assessment

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Almost half of the respondents surveyed by the BfR stated that they consumed food supplements in order to treat illnesses or other health conditions. However, unlike medical drugs, food supplements are not intended to be used as treatment. They are not allowed to be promoted with illness-related claims. It is undisputed that vitamins and minerals generally fulfil important functions within the body and that deficiencies can lead to health impairments. However, unnecessary additional intake of vitamins or minerals can lead to undesired health effects, as is explained in the new issue of BfR2GO. In an interview, BfR scientist Dr Nadiya Bakhiya details possible health risks posed by consumption of food supplements with plant-based ingredients. 

In addition to the main topic and just in time for summer, the new issue provides tips for better barbecuing to help avoid pathogens and the development of health-hazardous substances which might sully festive gatherings. In an interview with BfR2GO, Dr Inge Paulini, the President of the German Federal Office for Radiation Protection, explains that while sunscreen offers protection against skin cancer-causing UV radiation, other measures are more important. 

The article “Exposed” illuminates the concept of: the degree to which the human organism is exposed to a potentially hazardous substance – via food intake, inhalation or through the skin – is a major factor in the associated health risk. Additionally, the new issue of BfR2GO takes a look at chili, a spicy risk, as well as at the undesired health effects which may arise from flavouring substances in e-cigarette liquids. Further topics include miniature organ replicas meant to eventually replace animal experiments, foodborne diseases and their increasing prevalence due to climate change, and the intake of substances potentially hazardous to health through the use of period products or the consumption of beverages from PET bottles. 

As always, the BfR2GO Science Magazine is compact and knowledge-packed and provides up-to-date and well-founded information about research and the assessment of this research in consumer health protection and for the protection of laboratory animals. Each issue of BfR2GO presents an issue related to one of the BfR’s current fields of work as the main topic. It additionally includes reports, interviews, and news from all of the BfR’s areas of work. 

The magazine is published on the BfR website in both German and English and can be downloaded there for free. Anyone who wishes to receive future issues of BfR2GO can subscribe for free at:

https://www.bfr.bund.de/en/publications/bfr2go/

About the BfR

The German Federal Institute for Risk Assessment (BfR) is a scientifically independent public health institute within the portfolio of the German Federal Ministry of Agriculture, Food and Regional Identity (BMLEH). It provides advice to the Federal Government as well as the Federal States (‘Laender’) on questions related to food, feed, chemical and product safety. The BfR conducts its own research on topics closely related to its assessment tasks.

This text version is a translation of the original German text, which is the only legally binding version.

 

Some people could sound angrier when complaining, new study finds

The French sound sad, Québécois sound angry: research shows different cultures may utter complaints differently, highlighting that complaints could be shaped by cultural and social conventions

Frontiers

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It has long been established that emotions reflect in our voice – this helps us communicate more purposefully and gives listeners cues as to how they should interpret what we say. But what emotions predominate in complaints – and how do they differ between groups? Researchers in Switzerland and Canada investigated and published their findings in Frontiers in Communication.

“Complaining is differentiated from neutral speech by changes in vocal expression. Complainers tend to change their intonation, pitch, rhythm, and emphasis, making them sound more emotive and expressive,” said first author Dr Maël Mauchand, a neuroscientist at the Swiss Center for Affective Sciences at the University of Geneva. “We show that complaining strategies show specific variations across two francophone cultures, with Québécois sounding more angry or surprised and French speakers sounding sadder.”

Conventions for complaints

Knowing in detail what complaints sound like could help researchers understand how they are perceived and how they elicit empathy in others. For the experiment, the researchers recruited eight speakers (four French and four Québécois) who recorded 84 short sentences in a neutral and a complaining voice – irrespective of linguistic content. Then, 40 people living in Quebec, half of which had grown up in France, assessed the emotions (happy, sad, angry, surprised, fearful, disgusted) in a selection of utterances.

“Complaining strategies seem consistent towards defining a general ‘complaining tone of voice’, with a few specific cultural variations,” Mauchand explained. For example, complaints were delivered with a higher and more variable pitch as well as louder and slower in general. These parameters differed slightly between cultures, for example, the French spoke at a higher pitch. In contrast, Québécois showed greater pitch variability, which indicates more pronounced changes in intonation across their complaint.

Sad or angry?

Complaints reconstruct emotional states and speakers complain to convey or re-live a negative experience. Accordingly, they convey strong emotions that stress this negativity. On an emotional level, listening participants rated Québécois as sounding angrier, more surprised, and more disgusted than French speakers, whereas French speakers were rated as sounding sadder.

“There may be cultural norms on what a complaint sounds like in France or in Quebec, influenced by their use,” Mauchand explained. “The French are said to complain quite often – if complaining is frequent and ritualized, it makes sense that complainers try to make their voice sound less aggressive, for example by using higher intonation and sounding more sad than angry.”

On the other hand, Québécois are generally more expressive in their speech, which might explain why high-arousal emotions like surprise or anger are more prominent in their complaints.

“There may be social conventions on what a complaint sounds like in a particular culture, which can be learned as we grow up,” Mauchand pointed out. “How we complain is a subtle interplay between emotion, social context, and cultural display rules.”

Beyond words

The researchers pointed out that their sample size, limited in both the number of speakers and cultures represented, could mean their results aren’t generalizable. In addition, complaints may take other forms in longer statements or interactions. Further research could examine if such cultural differences can be found in speakers of the same language who grew up in different cultures. While the trend might be universal, such variations could depend on the cultural importance of complaints: how often a culture complains, why people complain, and how complaints are received by others, the team said.

The work highlights the critical role of the tone of voice in social interactions and the information may be used in studies about communication disorders and in therapy training. “As an immediate application, it could encourage people to be more attentive,” concluded Mauchand. “Not just to what people say, but how they say it – and what it implies.”

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Journal

Frontiers in Communication

DOI

10.3389/fcomm.2025.1592994 

Method of Research

Experimental study

Subject of Research

People

Article Title

The Sound of Complaints

Article Publication Date

22-Jul-2025