Fused-ring nanothread synthesized via high-pressure polymerization of naphthalene

Fei, Y.*; Wang, Y.*; Zhang, J.*; Liu, J.*; Zhao, Z.*; Hattori, Takanori; Abe, Jun*; Dong, X.*; Mao, H.-K.*; Zheng, H.*; et al.

Chemistry; A European Journal, 32(31), p.e71096_1 - e71096_11, 2026/08

https://doi.org/10.1002/chem.71096

We systematically investigated the high-pressure polymerization of naphthalene, the simplest polycyclic aromatic hydrocarbons (PAHs), using multiple cutting-edge methods. Naphthalene molecules were stacked in herringbone style, and underwent [4+2] cycloaddition reactions along the a-b direction above 20 GPa, yielding one-dimensional Carbon nanothreads (CNThs). In contrast to the formation of many CNThs, the nucleation of the CNThs occurs during compression while their growth proceeds during decompression, which is likely prevalent among herringbone-stacked aromatics. The unit cell of the obtained CNTh crystal is determined and the possible structure of the CNTh product is also proposed. Our research reveals the polymerization characteristics of naphthalene under high pressure, highlighting the fact that the slip-angle plays an important role in governing the polymerization pathway.

Assessing and tackling the barocaloric fatigue for applicable solid-state refrigeration

Xue, J.*; Huang, D.*; Hattori, Takanori; Li, L.*; Feng, Y.*; Wang, H.*; Fan, X.*; Yao, J.*; Wang, Y.*; Liu, Z.*; et al.

Applied Physics Letters, 128(20), p.201903_1 - 201903_8, 2026/05

https://doi.org/10.1063/5.0333322

The cycling fatigue and barocaloric response of NHI is directly assessed under loading-unloading cycles with stress up to 100,MPa, with the adiabatic temperature change () decaying from 15,K to approximately 0.8,K after 100 cycles. X-ray diffraction, Raman spectroscopy, and neutron diffraction concertedly reveal the existence of the residual high-pressure phase even after the first unloading, whose fraction is rapidly increased to 90% at the 100th cycle. A phenomenological model is developed to elucidate this fatigue behavior, and an excellent agreement with experimental data has been achieved. To relieve the intergranular stress and enhance the mobility of grains, we encapsulate the composite of NHI particles and silicone oil into a 3D-printed polymer shell. Such an architectural tailoring has markedly improved the cyclic stability of the barocaloric effect with rising to c.a. 4.6,K after 100 cycles. Our results establish a fundamental understanding of the barocaloric fatigue behavior and pave a feasible route to applicable barocaloric cooling technology.

Real-space local dynamics in 1,2,3-triazole using inelastic neutron scattering

Shinohara, Yuya*; Iwashita, Takuya*; Nakanishi, Masahiro*; Liu, Y.*; Cooper, V. R.*; Kofu, Maiko*; Nirei, Masami; Dmowski, W.*; Hickner, M. A.*; Egami, Takeshi*

Journal of Physical Chemistry B, 129(47), p.12330 - 12337, 2025/11

https://doi.org/10.1021/acs.jpcb.5c06367

Study on time changes in proton beam passing current from ion source to RFQ at the J-PARC LINAC

Okabe, Kota; Shibata, Takanori*; Moriya, Katsuhiro; Okoshi, Kiyonori; Miyao, Tomoaki*; Otani, Masashi*; Liu, Y.*; Morishita, Takatoshi

Proceedings of 16th International Particle Accelerator Conference (IPAC25) (Internet), p.1527 - 1529, 2025/11

https://doi.org/10.18429/JACoW-IPAC2025-TUPS046

Pressure-driven solid-state radical polymerization toward carbon nanothread

Che, G.*; Tang, X.*; Liu, J.*; Lang, P.*; Fei, Y.*; Yang, X.*; Wang, Y.*; Gao, D.*; Wang, X.*; Ju, J.*; et al.

Nano Letters, 25(39), p.14467 - 14472, 2025/09

https://doi.org/10.1021/acs.nanolett.5c03977

Mechanochemical radical polymerization has unique advantages in the synthesis of polymer due to its reduced solvent consumption and adaptability of insoluble monomers. However, it suffers from the uncontrollable degradation of the formed polymers during reaction and new synthetic strategy with precise controllability needs to be developed. Here, by employing high static pressure up to 30 GPa, we found 1,3,5-trifluorobenzene undergoes radical polymerization by breaking the conjugated -bonds, and forms a carbon nanothread with high selectivity (Polymer-I polymorph). Based on the crystal structure at the threshold pressure and the calculated energy barriers for the bonding pathway, we concluded that the benzene-rings react via a 1-2 radical polymerization pathway. Our work highlights high pressure is a robust method to initiate the solid-state radical polymerization, even for very stable aromatics, and offers fresh insights for the synthesis of polymeric carbon-based materials with high selectivity.

All-temperature barocaloric effects at pressure-induced phase transitions

Zhao, X.*; Zhang, Z.*; Hattori, Takanori; Wang, J.*; Li, L.*; Jia, Y.*; Li, W.*; Xue, J.*; Fan, X.*; Song, R.*; et al.

Nature Communications (Internet), 16, p.7713_1 - 7713_8, 2025/08

https://doi.org/10.1038/s41467-025-63068-z

Caloric effects usually occur in the vicinity of solid-state phase transitions with a limited refrigeration temperature span. Here, we introduce and realize an unprecedented concept -all temperature barocaloric effect, i.e., a remarkable barocaloric effect in KPF across an exceptionally wide temperature span, from 77.5 to 300 K and potentially down to 4 K, covering typical room temperature, liquid nitrogen, liquid hydrogen, and liquid helium refrigeration regions. The directly measured barocaloric adiabatic temperature change reaches 12 K at room temperature and 2.5 K at 77.5 K upon the release of a 250 MPa pressure. This effect is attributed to a persistent phase transition to a rhombohedral high pressure phases. We depict the thermodynamic energy landscape to account for the structural instability. This unique all-temperature barocaloric effect presents a novel approach to highly applicable solid-state refrigeration technology, transcending the conventional multi-stage scenario.

Ordered graphane nanoribbons synthesized via high-pressure diels-alder polymerization of 2,2'-bipyrazine

Li, F.*; Tang, X.*; Fei, Y.*; Zhang, J.*; Liu, J.*; Lang, P.*; Che, G.*; Zhao, Z.*; Zheng, Y.*; Fang, Y.*; et al.

Journal of the American Chemical Society, 147(17), p.14054 - 14059, 2025/04

https://doi.org/10.1021/jacs.5c03116

We synthesized a crystalline graphane nanoribbon (GANR) via pressure-induced polymerization of 2,2'-bipyrazine (BPZ). By performing Rietveld refinement of in situ neutron diffraction data, nuclear magnetic resonance spectroscopy, infrared spectra, and theoretical calculation, we found that BPZ experienced Diels-Alder polymerization between the stacked aromatic rings, and formed extended boat-GANR structures with exceptional long-range order. The unreacted -C=N- groups bridge the two ends of the boat, and ready for further functionalization. The GANR has a bandgap of 2.25 eV, with booming photoelectric response (/ =18.8). Our work highlights that the high-pressure topochemical polymerization is a promising method for the precise synthesis of graphane with specific structure and desired properties.

Strong low-energy rattling modes enabled liquid-like ultralow thermal conductivity in a well-ordered solid

Liu, P.-F.*; Li, X.*; Li, J.*; Zhu, J.*; Tong, Z.*; Kofu, Maiko*; Nirei, Masami; Xu, J.*; Yin, W.*; Wang, F.*; et al.

National Science Review, 11(12), p.nwae216_1 - nwae216_10, 2024/12

https://doi.org/10.1093/nsr/nwae216

Brightening triplet excitons enable high-performance white-light emission in organic small molecules via integrating n-- transitions

Yang, Q.*; Yang, X.*; Wang, Y.*; Fei, Y.*; Li, F.*; Zheng, H.*; Li, K.*; Han, Y.*; Hattori, Takanori; Zhu, P.*; et al.

Nature Communications (Internet), 15, p.7778_1 - 7778_9, 2024/09

https://doi.org/10.1038/s41467-024-52196-7

Luminescent materials that simultaneously embody bright singlet and triplet excitons hold great potential in optoelectronics, signage, and information encryption. However, achieving high-performance white-light emission is severely hampered by their inherent unbalanced contribution of fluorescence and phosphorescence. Herein, we address this challenge by pressure treatment engineering via hydrogen bonding cooperativity effect to realize the mixture of n-- transitions, where the triplet state emission was boosted from 7% to 40% in isophthalic acid (IPA). A superior white-light emission based on hybrid fluorescence and phosphorescence was harvested in pressure-treated IPA, and the photoluminescence quantum yield was increased to 75% from the initial 19% (blue-light emission). In-situ high-pressure IR spectra, X ray diffraction, and neutron diffraction reveal continuous strengthening of the hydrogen bonds with the increase of pressure. Furthermore, this enhanced hydrogen bond is retained down to the ambient conditions after pressure treatment, awarding the targeted IPA efficient intersystem crossing for balanced singlet/triplet excitons population and resulting in efficient white-light emission. This work not only proposes a route for brightening triplet states in organic small molecule, but also regulates the ratio of singlet and triplet excitons to construct high-performance white-light emission.

In-plane movement of isolated poly(methacrylate) chains on a hydrophilic solid surface

Kawano, Masayuki*; Morimitsu, Yuma*; Liu, Y.*; Miyata, Noboru*; Miyazaki, Tsukasa*; Aoki, Hiroyuki; Kawaguchi, Daisuke*; Yamamoto, Satoru*; Tanaka, Keiji*

Macromolecules, 57(14), p.6625 - 6633, 2024/07

https://doi.org/10.1021/acs.macromol.4c00724