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Xu, J.*; Lang, P.*; Liang, S.*; Zhang, J.*; Fei, Y.*; Wang, Y.*; Gao, D.*; 服部 高典; 阿部 淳*; Dong, X.*; et al.
Journal of Physical Chemistry Letters (Internet), p.2445 - 2451, 2025/00
被引用回数：0 パーセンタイル：0.00(Chemistry, Physical)アルダー-エン反応は、アルケンとアリル水素との化学反応であり、C-C結合を構築する効率的な方法である。従来、この反応には触媒、高温、あるいは光触媒が必要であった。本研究では、触媒を用いずに室温下で加圧することで成功した1-ヘキセンのアルダー-エン反応を報告する。1-ヘキセンは4.3GPaで結晶化し、18GPaで重合してオレフィンを形成する。ガスクロマトグラフィー-質量分析法により、1-ヘキセンが高圧下でのアルダー-エン反応により二量体を生成することを発見した。その場中性子回折から、この反応過程はトポケミカル則に従わないことがわかった。理論計算により、1つのC-H 
結合と2つのアルケン
結合を含む6員環遷移状態が示され、そのエネルギーは20GPaまで圧縮すると明らかに減少した。本研究は、触媒を用いずに室温でアルダー-エン反応を実現する新規かつ有望な方法を提供し、この重要な反応の応用を拡大するものである。
加藤 浩之*; 室山 瑞穂*; 小早川 なの*; 棟安 陸*; 津田 泰孝; 村瀬 菜摘*; 渡部 誠也*; 山田 剛司*; 兼松 佑典*; 立川 仁典*; et al.
Journal of Physical Chemistry Letters (Internet), 15(43), p.10769 - 10776, 2024/10
被引用回数：1 パーセンタイル：0.00(Chemistry, Physical)The charge transfer capability associated with chemical reactions at metal-organic interfaces was studied via the atomic H addition reaction for an imidazole-terminated alkanethiolate self-assembled monolayer (Im-SAM) film on Au(111) using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, infrared reflection absorption spectroscopy (IRAS), work function measurements, and density functional theory (DFT) calculations. The imidazolium cation is a stable species in liquids, therefore, it is pertinent to determine whether the hydrogenation reactions of the imidazole groups produce imidazolium cations accompanied by electron transfer to the Au substrate, even in the absence of solvate and/or counterions on the insulating alkanethiolate layer. The analyses indicated that the imidazolium moieties in Im-SAM formed during atomic H irradiation, and some of the imidazolium radicals became cations. Theoretical model calculations also revealed that the total energies and molecular orbital levels satisfied the imidazolium cation formation associated with electron transfer.
7垣内 拓大*; 穴井 亮太*; 佐伯 大殊*; 津田 泰孝; 吉越 章隆
Journal of Physical Chemistry C, 128(31), p.13052 - 13063, 2024/08
被引用回数：0 パーセンタイル：0.00(Chemistry, Physical)Hf薄膜を形成したSi(111)基板の界面および表面の酸化プロセスを超音速酸素分子ビーム(SOMB)と放射光光電子分光法により研究した。0.5単層(ML)のHf-Si(111)は、HfSiとHfSi
を含む。0.03eVの並進エネルギー(Et)を持つ熱酸素分子を照射すると、HfSiはHf
価に酸化された。Etが0.39eVのSOMB照射により、他のHfSiはHf
に酸化された。熱酸素曝露後、金属Hfはトラッピングを介した解離吸着を経てHfO
に非局所的に酸化された。一方、偏析したSi原子は2.2eVのSOMB照射によって酸化され、表面にSiOが生成した。
熊田 高之; 岩原 大輔*; 西辻 祥太郎*; 阿久津 和宏*; 三浦 大輔; 元川 竜平; 杉田 剛; 鳥飼 直也*; 網野 直也*; 奥 隆之; et al.
Journal of Physical Chemistry C, 128(21), p.8797 - 8802, 2024/05
被引用回数：0 パーセンタイル：0.00(Chemistry, Physical)スピンコントラスト変調中性子反射率法を用いて自動車用ゴムタイヤに用いるブタジエンゴムがシランカップリング剤を通じてシリカ表面とどのように結合しているかを調べた。ブタジエンゴムとシランカップリング剤をシリコン基板にコートした後アニールした試料では、シリコン基板表面にシランカップリング剤とポリブタジエンが7:3の比で絡みあった膜が形成されるのに対し、シランカップリング剤をあらかじめコートした後にポリブタジエンをコートした試料では両者の絡み合いが足りないために容易に剥離してしまうことを突き止めた。
molecule generation from dissociatively adsorbed water on TiO through photoexcitation加藤 弘一*; 長塚 直樹*; 福谷 克之
Journal of Physical Chemistry C, 128(20), p.8188 - 8198, 2024/05
被引用回数：1 パーセンタイル：41.44(Chemistry, Physical)The dissociative adsorption of water, migration of hydrogen, and molecular hydrogen generation on anatase and rutile TiO surfaces were studied by first-principles calculations. Whereas dissociated H and OH are adsorbed strongly on both TiO surfaces, the adsorption energies were substantially decreased when H and OH were combined with polarons, which can be generated through photoexcitation. The H atom coupled with a polaron was found to undergo codiffusion. While a large polaron smoothly follows the H atom migration in anatase, a small polaron in rutile stochastically moves and abruptly jumps between neighboring Ti sites during the H atom migration, exerting strong retardation to the H atom migration. The favorable path for two H atoms coupled with polarons to form an H molecule was examined. It was found that the energy barrier is low when an H atom migrates to the H-adsorbed O site to form a 2H-coordinated O atom, followed by H desorption on both anatase and rutile surfaces. The atom of the oxazole forms a more stable 
electronic configuration by the adsorption of two H atoms. The two H atoms on the same O atom, coupled with polarons, possibly tunnel through the energy barrier to a desorbing H molecule. It is also shown that an HO molecule possibly desorbs from the same 2H=O configuration.
篠原 佑也*; 岩下 拓哉*; 中西 真大*; Osti, N. C.*; 古府 麻衣子; 楡井 真実; Dmowski, W.*; 江上 毅*
Journal of Physical Chemistry B, 128(6), p.1544 - 1549, 2024/02
被引用回数：2 パーセンタイル：56.79(Chemistry, Physical)Improving the proton transport in polymer electrolytes impacts the performance of next-generation solid-state batteries. However, little is known about proton conductivity in nonaqueous systems due to the lack of an appropriate level of fundamental understanding. Here, we studied the proton transport in small molecules with dynamic hydrogen bonding, 1,2,3-triazole, as a model system of proton hopping in a nonaqueous environment using incoherent quasi-elastic neutron scattering. By using the jump-diffusion model, we identified the elementary jump-diffusion motion of protons at a much shorter length scale than those by nuclear magnetic resonance and impedance spectroscopy for the estimated long-range diffusion. In addition, a spatially restricted diffusive motion was observed, indicating that proton motion in 1,2,3-triazole is complex with various local correlated dynamics. These correlated dynamics will be important in elucidating the nature of the proton dynamics in nonaqueous systems.
岡崎 宏之*; 出崎 亮*; 越川 博*; 松村 大樹; 池田 隆司*; 山本 春也*; 八巻 徹也*
Journal of Physical Chemistry C, 127(49), p.23628 - 23633, 2023/12
被引用回数：1 パーセンタイル：11.44(Chemistry, Physical)The change in the oxygen adsorption states of Pt nanoparticles by ion irradiation of the carbon support is studied by in situ X-ray absorption spectroscopy measurements. The difference spectra around a Pt L
edge due to oxygen adsorption are recorded, and a lowering in the Pt-O antibonding level by the ion irradiation is observed, thus resulting in a weakening of the Pt-O bond. This indicates that the introduction of vacancies in the carbon support would result in weak Pt-O bonds assumable through the stronger Pt-C interaction, which is considered to enhance the oxygen reduction reaction activity of the deposited Pt nanoparticles. Theoretical studies have demonstrated that the vacancies affect Pt through the Pt-C interaction and then result in the weakening of the Pt-O bond.
辻 勇人*; 中畑 雅樹*; 菱田 真史*; 瀬戸 秀紀*; 元川 竜平; 井上 大傑*; 江川 泰暢*
Journal of Physical Chemistry Letters (Internet), 14(49), p.11235 - 11241, 2023/12
被引用回数：5 パーセンタイル：65.84(Chemistry, Physical)This work investigates the water-fraction dependence of the aggregation behavior of hydrophobic solutes in water-tetrahydrofuran (THF) and the elucidation of the role of THF using fluorescence microscopy, dynamic light scattering, neutron and X-ray scattering, as well as photoluminescence measurements. Based on the obtained results, the following model is proposed: hydrophobic molecules are molecularly dispersed in the low-water-content region (10-20 vol %), while they form mesoscopic particles upon increasing the water fraction to 
30 vol percent. This abrupt change is due to the composition fluctuation of the water-THF binary system to form hydrophobic areas in THF, followed by THF-rich droplets where hydrophobic solutes are incorporated and form loose aggregates. Further increasing the water content prompts the desolvation of THF, which decreases the particle size and generates tight aggregates of solute molecules. This model is consistent with the luminescence behavior of the solutes and will be helpful to control the aggregation state of hydrophobic solutes in various applications.
田村 和久
Journal of Physical Chemistry C, 127(46), p.22733 - 22739, 2023/11
被引用回数：1 パーセンタイル：0.00(Chemistry, Physical)Au(111)上のBiのUPD反応に関して、1M HClO中と[BMIM]BF中での反応を比較した。可視光反射率測定および表面X線散乱測定を行った結果、Biの反応電子数はどちらの電解液中でも同じ値であったが、一方で反応過程は大きくことなることが分かった。この違いは、Biの溶媒和の違いに起因すると思われる。
neutron diffraction小林 大輝*; 小松 一生*; 伊藤 颯*; 町田 真一*; 服部 高典; 鍵 裕之*
Journal of Physical Chemistry Letters (Internet), 14(47), p.10664 - 10669, 2023/11
被引用回数：2 パーセンタイル：30.03(Chemistry, Physical)氷IVは、水分子が配向乱れを示す氷の準安定高圧相である。配向秩序は他の氷相ではよく観測されるが、氷IVでは報告されていない。われわれは、DClを添加したDO氷IVのその場粉末中性子回折実験を行い、氷IVにおける水素秩序を調べた。その結果、単位胞体体積の温度微分dV/dTが約120Kで急激に変化することを発見し、またリートベルト解析により低温でわずかに水素が秩序化することを明らかにした。D1サイトの占有率は0.5から外れており、そのずれは試料をより高い圧力で冷却すると増加し、2.38GPa, 58Kで0.282(5)に達した。この結果は、氷IVに対応する低対称の水素秩序状態の存在を証明するものである。しかしながら、高圧下での徐冷によって、完全に水素が秩序化した氷IV相を実験的に生成することは難しいようである。
ortho-para conversion on a metal surface; Interplay between electron and phonon systems植田 寛和; 福谷 克之
Journal of Physical Chemistry Letters (Internet), 14(34), p.7591 - 7596, 2023/08
被引用回数：1 パーセンタイル：13.97(Chemistry, Physical)Clarifying energy transfer processes in molecular adsorption on solid surfaces is essential to understand gas-surface interaction. Unlike the vibrational-energy transfer processes, which are thought to be well understood in detail, the rotational-energy transfer process still remains unclear. Considering the interconversion between ortho and para states of H is accompanied by the nuclear spin flip and the rotational-energy transfer, the surface-temperature dependence of the ortho-to-para conversion of molecularly chemisorbed H on Pd(210) is studied. The conversion rate is accelerated with increasing surface temperature. Based on the conversion model proposed for metal surfaces, we analyze the temperature dependence of the conversion rate taking account of both electron and phonon systems of the substrate. The rotational-energy transfer is most likely mediated by surface electrons with an assistance of the substrate phonons.
熊田 高之; 中川 洋; 三浦 大輔; 関根 由莉奈; 元川 竜平; 廣井 孝介; 稲村 泰弘; 奥 隆之; 大石 一城*; 森川 利明*; et al.
Journal of Physical Chemistry Letters (Internet), 14(34), p.7638 - 7643, 2023/08
被引用回数：0 パーセンタイル：0.00(Chemistry, Physical)スピンコントラスト変調中性子小角散乱法を用いて急冷したグルコース濃厚溶液中に生成するナノアイス結晶の構造解析を行ったところ、厚さ1nm程度、半径数十nm以上の平面上の氷晶が生成していることを見出した。本結果はグルコース分子が特定の成長面に吸着することによりその面からの結晶成長を阻害していることを示す。
稲川 康平*; 松村 大樹; 谷口 昌司*; 上垣 伸弥*; 中山 智仁*; 浦野 純乃介*; 青谷 拓朗*; 田中 裕久*
Journal of Physical Chemistry C, 127(24), p.11542 - 11549, 2023/06
被引用回数：0 パーセンタイル：0.00(Chemistry, Physical)Passive autocatalytic recombiner (PAR) represents a potential technology for ensuring process safety in the hydrogen society. PARs function through the catalytic oxidation of generated or leaked hydrogen, facilitating its conversion into water and effectively mitigating the risk of hydrogen explosions. CO is recognized as a catalyst poison that hampers surface catalytic reactions. To investigate the negative effects of CO on the local structure of platinum metal nanoparticle catalysts during water formation, in situ and time-resolved X-ray absorption spectroscopy analyses were conducted. The results revealed that the Pt-Fe/CZY catalyst exhibited notable hydrogen oxidation activity even in the presence of CO. The enhanced performance can be attributed to the combined effects of Pt-Fe alloy composition and CZY support materials.
Massey, D.*; Williams, C. D.*; Mu, J.*; Masters, A. J.*; 元川 竜平; 青柳 登; 上田 祐生; Antonio, M. R.*
Journal of Physical Chemistry B, 127(9), p.2052 - 2065, 2023/03
被引用回数：2 パーセンタイル：17.10(Chemistry, Physical)There is an ever-increasing body of evidence that metallic complexes, involving amphiphilic ligands, do not form normal solutions in organic solvents. Instead, they form complex fluids with intricate structures. For example, the metallic complexes may aggregate into clusters and these clusters themselves may aggregate into super-clusters. In order to gain a deeper insight into the mechanisms at play, we have used an improved force field to conduct extensive molecular dynamics simulations of a system composed of zirconium nitrate, water, nitric acid, tri-
-butyl phosphate and -octane. The important new finding is that a dynamic equilibrium between the cis and trans isomers of the metal complex is likely to play a key role in the aggregation behavior. The isolated cis and trans isomers have similar energies but simulation indicates that the clusters consist predominantly of cis isomers. With increasing metal concentration, we hypothesize that more clustering occurs and the chemical equilibrium shifts towards the cis isomer. It is possible that such isomeric effects play a role in the liquid-liquid extraction of other species and the inclusion of such effects in flowsheet modelling may lead to a better description of the process.
Ye, X.*; 下川 航平*; 毛塚 有飛*; 畠山 拓也*; Li, H.*; 市坪 哲
Journal of Physical Chemistry C, 127(11), p.5210 - 5218, 2023/03
被引用回数：1 パーセンタイル：11.44(Chemistry, Physical)In this study, wide-range compositions in Mg-Zn-Mn oxide systems were investigated to understand its phase stability for the development of high-energy-density rechargeable Mg batteries. The obtained results showed that the stability of the spinel structure can be significantly improved by compositionally incorporating stable XO (X = Zn, Mg) with 
-MnO. In particular, (i) the equimolar mixing of XO and MnO is essential to obtain a single-phase cubic spinel structure and (ii) a higher Zn/Mg ratio is effective for preventing the formation of an irreversible rock salt phase to decrease the overpotential during discharge/charge cycling.
Balois-Oguchi, M. V.*; 早澤 紀彦*; 保田 諭; 池田 勝佳*; Nguyen, T. Q.*; Esca
o, M. C.*; 田中 拓男*
Journal of Physical Chemistry C, 127(12), p.5982 - 5990, 2023/03
被引用回数：11 パーセンタイル：73.09(Chemistry, Physical)グラフェンのマイクロメートルサイズのリンクルは、その形状とそれが生み出すひずみの変化により、グラフェンの電子特性に影響を与えることが知られている。本研究では、チップ増強ラマン分光法(TERS)を使用して、幅1.9nmのグラフェンのしわのひずみ分布とドーピングを分析した。その結果、グラフェンのしわのTERS画像とAu(111)基板の電子ラマン散乱(eRS)の間に強い相関があることを発見した。これらの結果は、しわなどのナノメートルサイズの形状の製造直後の物理的および電子特性を、ナノデバイスの特性評価に不可欠なTERSを使用して詳細に調査および研究できることを実証した。
Cs NMR chemical shift of clay minerals via machine learning and DFT-GIPAW calculations大窪 貴洋*; 武井 滉洋*; 舘 幸男; 深津 勇太; 出口 健三*; 大木 忍*; 清水 禎*
Journal of Physical Chemistry A, 127(4), p.973 - 986, 2023/02
被引用回数：6 パーセンタイル：73.30(Chemistry, Physical)粘土鉱物へのCsの吸着サイトの特定は、環境化学の分野で研究されてきた。核磁気共鳴(NMR)実験によって、吸着されたCsの局所構造を直接観察することが可能である。固体NMR実験から得られたCsのNMRパラメータは、吸着されたCsの局所的な構造に敏感である。しかしながら、NMRデータだけからCsの吸着位置を決定することは困難であった。本研究では、機械学習と実験的に観察されたケミカルシフトを組み合わせることにより、粘土鉱物に吸着されたCsの吸着位置を特定するためのアプローチについて提示する。原子配置の記述子とNMRによるケミカルシフトの第一原理計算結果を関連付けて評価する機械学習の線形リッジ回帰モデルを構築した。これにより、原子配置の構造データからCsのケミカルシフトを高速で計算することが可能となった。機械学習モデルによって、実験的に観察された化学シフトから逆解析を行うことにより、Cs吸着位置を導き出すことが可能になる。
point group symmetry (M(II) = Zn(II) and Mg(II))増田 優花*; 阪田 潮実*; 萱原 早織*; 入江 夏生*; 古府 麻衣子; 河野 洋平*; 榊原 俊郎*; 堀井 洋司*; 梶原 孝志*
Journal of Physical Chemistry C, 127(6), p.3295 - 3306, 2023/02
被引用回数：4 パーセンタイル：34.64(Chemistry, Physical)Trinuclear M(II)-Gd(III)-M(II) complexes 1 (M = Zn), 2 (M = Mg), and the magnetically dilute sample 1' were synthesized and the slow magnetization relaxation originating from Gd(III) ions was investigated in detail. These complexes are crystallographically isostructural and belong to point group symmetry, with M-Gd-M arrayed on the crystallographic 3-fold axis. From the angular-resolved magnetization of a single crystal of 1, an easy-axis-type magnetic anisotropy of Gd(III) with an anisotropy parameter D of -0.21(3) K were revealed. All the complexes underwent slow relaxation under the application of an external magnetic field. The temperature dependence of the relaxation rate 
differed considerably between 1' and 1, 2. The discrepancy can be attributed to the presence of competing multiple relaxation processes, such as direct and Raman processes, and at dilution, the direct process becomes faster, leading to its predominance in 1'. For 1 and 2, the larger power number (~1.5) was attributed to the significantly greater contribution from the Raman process, which may be originated from intramolecular atomic vibrations.
NH and CaNH thin films by reactive magnetron sputtering under hydrogen partial pressure controlChon, S.*; 福谷 克之; 他8名*
Journal of Physical Chemistry Letters (Internet), 13(43), p.10169 - 10174, 2022/11
被引用回数：0 パーセンタイル：0.00(Chemistry, Physical)Calcium compounds with N and H are promising catalysts for NH conversion, and their epitaxial thin films provide a platform to quantitatively understand the catalytic activities. Here we report the selective epitaxial growth of CaNH and CaNH thin films by controlling the hydrogen partial pressure (
) during reactive magnetron sputtering. We find that the hydrogen charge states can be tuned by : CaNH containing H
is formed at 
Pa, while CaNH containing H
is formed at 
Pa. In situ plasma emission spectroscopy reveals that the intensity of the Ca atomic emission (422 nm) decreases as increases, suggesting that Ca reacts with H and N to form CaNH at lower , whereas at higher , CaH
is first formed on the target surface and then sputtered to produce CaNH. This study provides a novel route to control the hydrogen charge states in Ca-N-H epitaxial thin films.
日下 良二; 渡邉 雅之
Journal of Physical Chemistry Letters (Internet), 13(30), p.7065 - 7071, 2022/08
被引用回数：10 パーセンタイル：73.71(Chemistry, Physical)Understanding the chemistry of elements at the bottom of the periodic table is a challenging goal in chemistry. Observing actinide species at interfaces using interface-selective second-order nonlinear optical spectroscopy, such as vibrational sum frequency generation (VSFG) spectroscopy, is a promising route for developing heavy element chemistry; however, such attempts are scarce. Here, we investigated the phase transfer mechanism of uranyl ions (UO
) in solvent extraction using the di-(2-ethylhexyl)phosphoric acid (HDEHP) extractant dissolved in dodecane organic phase by probing the oil/water liquid-liquid interface using VSFG spectroscopy. The POO symmetric stretch vibrational signals of the HDEHP ligands clearly demonstrated that uranyl ions form interfacial complexes with HDEHP at the oil/water interface. The interfacial uranyl-HDEHP complexes were formed with uranyl ions coming from both the aqueous and oil phases, strongly suggesting that the interfacial complex is an intermediate to cross the oil/water interface. Density functional theory (DFT) calculations proposed the molecular structure of the interfacial uranyl-HDEHP complex.
