Solid-state Alder-ene reaction of 1-hexene under high pressure

Xu, J.*; Lang, P.*; Liang, S.*; Zhang, J.*; Fei, Y.*; Wang, Y.*; Gao, D.*; Hattori, Takanori; Abe, Jun*; Dong, X.*; et al.

Journal of Physical Chemistry Letters (Internet), p.2445 - 2451, 2025/00

https://doi.org/10.1021/acs.jpclett.4c03696

The Alder-ene reaction is a chemical reaction between an alkene with an allylic hydrogen, and it provides an efficient method to construct the C-C bond. Traditionally, this reaction requires catalysts, high temperatures, or photocatalysis. In this study, we reported a high-pressure-induced solid-state Alder-ene reaction of 1-hexene at room temperature without a catalyst. 1-Hexene crystallizes at 4.3 GPa and polymerizes at 18 GPa, forming olefins. By exploring gas chromatography-mass spectrometry, we discovered that 1-hexene generates dimeric products through the Alder-ene reaction under high pressures. The in situ neutron diffraction shows that the reaction process did not obey the topochemical rule. A six-membered ring transition state including one C-H bond and two alkene bonds was evidenced by the theoretical calculation, whose energy obviously decreased when compressed to 20 GPa. Our work offers a novel and promising method to realize the Alder-ene reaction at room temperature without a catalyst, expanding the application of this important reaction.

Coverage dependence upon early oxidation stages of hafnium-adsorbed Si(111)-77

Kakiuchi, Takuhiro*; Anai, Ryota*; Saiki, Taiju*; Tsuda, Yasutaka; Yoshigoe, Akitaka

Journal of Physical Chemistry C, 128(31), p.13052 - 13063, 2024/08

https://doi.org/10.1021/acs.jpcc.4c02368

0xidation at the interface and the surface of Si(111) substrate with thin Hf films were studied using synchrotron radiation photoelectron spectroscopy in conjunction with supersonic oxygen molecular beams (SOMB). An Hf/Si(111) with a coverage of 0.5 monolayer (ML) included HfSi and HfSi. Following exposures to thermal oxygen molecules with a translational energy (Et) of 0.03 eV, HfSi was oxidized into Hf valence. Following SOMB irradiation with Et of 0.39 eV, the other HfSi could be oxidized into the Hf. Following the thermal O exposures, the metallic Hf was nonlocally oxidized to HfO via trapping-mediated dissociative adsorption. Meanwhile, the segregated Si atoms were oxidized by SOMB irradiation with 2.2 eV and SiO was generated on the surface.

H molecule generation from dissociatively adsorbed water on TiO through photoexcitation

Kato, Koichi*; Nagatsuka, Naoki*; Fukutani, Katsuyuki

Journal of Physical Chemistry C, 128(20), p.8188 - 8198, 2024/05

https://doi.org/10.1021/acs.jpcc.3c08216

Weakened oxygen adsorbing the Pt-O bond of the Pt catalyst induced by vacancy introduction into carbon support

Okazaki, Hiroyuki*; Idesaki, Akira*; Koshikawa, Hiroshi*; Matsumura, Daiju; Ikeda, Takashi*; Yamamoto, Shunya*; Yamaki, Tetsuya*

Journal of Physical Chemistry C, 127(49), p.23628 - 23633, 2023/12

https://doi.org/10.1021/acs.jpcc.3c04117

Comparative study of the underpotential deposition of Bi in an aqueous electrolyte and an ionic liquid

Tamura, Kazuhisa

Journal of Physical Chemistry C, 127(46), p.22733 - 22739, 2023/11

https://doi.org/10.1021/acs.jpcc.3c05404

The underpotential deposition of Bi on Au(111) electrode in 1 M HClO solution and 1-butyl-3-methylimidazolium tetrafluoroborate was investigated using visible light reflectance measurement and surface X-ray scattering techniques. The electrosorption valency of the UPD reaction of Bi was elucidated and it was found that in both 1 M HClO and 1-butyl-3-methylimidazolium tetrafluoroborate the electrosorption valency was smaller than 3, but the detail process in the UPD reaction was different between in two electrolytes. The difference may be originated from the difference in the solvation status of Bi rather than the electrical double layer structure.

Polarized neutrons observed nanometer-thick crystalline ice plates in frozen glucose solution

Kumada, Takayuki; Nakagawa, Hiroshi; Miura, Daisuke; Sekine, Yurina; Motokawa, Ryuhei; Hiroi, Kosuke; Inamura, Yasuhiro; Oku, Takayuki; Oishi, Kazuki*; Morikawa, Toshiaki*; et al.

Journal of Physical Chemistry Letters (Internet), 14(34), p.7638 - 7643, 2023/08

https://doi.org/10.1021/acs.jpclett.3c01448

The structure of nano-ice crystals in rapidly frozen glucose solution was elucidated by using spin-contrast-variation small-angle neutron scattering, which distinguishes the nano-ice crystal signal from the frozen amorphous solution signal by the polarization-dependent neutron scattering. The analysis revealed that the nano-ice crystals form a planar structure with a diameter exceeding tens of nanometers and a thickness of 1 nm, which is close to the critical nucleation size. This result suggests that the glucose molecules are preferentially bound to a specific face of nano-ice crystals, and then block the crystal growth perpendicular to that face.

Development of hydrogen oxidation reaction catalysts to overcome CO poisoning and elucidation of reaction mechanism

Inagawa, Kohei*; Matsumura, Daiju; Taniguchi, Masashi*; Uegaki, Shinya*; Nakayama, Tomohito*; Urano, Junnosuke*; Aotani, Takuro*; Tanaka, Hirohisa*

Journal of Physical Chemistry C, 127(24), p.11542 - 11549, 2023/06

https://doi.org/10.1021/acs.jpcc.3c02237

Probing strain and doping along a graphene wrinkle using tip-enhanced Raman spectroscopy

Balois-Oguchi, M. V.*; Hayazawa, Norihiko*; Yasuda, Satoshi; Ikeda, Katsuyoshi*; Nguyen, T. Q.*; Escao, M. C.*; Tanaka, Takuo*

Journal of Physical Chemistry C, 127(12), p.5982 - 5990, 2023/03

https://doi.org/10.1021/acs.jpcc.2c08529

Micrometer-sized wrinkles in graphene are known to affect the electronic properties of graphene due to their shape and the strain variations they create. Here, we analyze the strain distribution and doping of a graphene wrinkle having 1.9 nm width using tip-enhanced Raman spectroscopy (TERS) in ambient conditions. We found a strong correlation between the TERS images of the graphene wrinkle and the electronic Raman scattering (eRS) of the Au(111) substrate. Our work demonstrates that the as-fabricated physical and electronic properties of nanometer-sized features, such as wrinkles, can be probed and studied in detail with TERS which is essential for nanodevice characterization.

New approach to understanding the experimental Cs NMR chemical shift of clay minerals via machine learning and DFT-GIPAW calculations

Okubo, Takahiro*; Takei, Akihiro*; Tachi, Yukio; Fukatsu, Yuta; Deguchi, Kenzo*; Oki, Shinobu*; Shimizu, Tadashi*

Journal of Physical Chemistry A, 127(4), p.973 - 986, 2023/02

https://doi.org/10.1021/acs.jpca.2c08880

The identification of adsorption sites of Cs on clay minerals has been studied in the fields of environmental chemistry. The nuclear magnetic resonance (NMR) experiments allow direct observations of the local structures of adsorbed Cs. The NMR parameters of Cs, derived from solid-state NMR experiments, are sensitive to the local neighboring structures of adsorbed Cs. However, determining the Cs positions from NMR data alone is difficult. This paper describes an approach for identifying the expected atomic positions of Cs adsorbed on clay minerals by combining machine learning (ML) with experimentally observed chemical shifts. A linear ridge regression model for ML is constructed from the smooth overlap of atomic positions descriptor and gauge-including projector augmented wave (GIPAW) ab initio data. The Cs chemical shifts can be instantaneously calculated from the Cs positions on any clay layers using ML. The inverse analysis from the ML model can derive the atomic positions from experimentally observed chemical shifts.

Selective epitaxial growth of CaNH and CaNH thin films by reactive magnetron sputtering under hydrogen partial pressure control

Chon, S.*; Fukutani, Katsuyuki; 8 of others*

Journal of Physical Chemistry Letters (Internet), 13(43), p.10169 - 10174, 2022/11

https://doi.org/10.1021/acs.jpclett.2c02617