Article
Chemistry, Physical
Dujuan Meng, Sophia Sagala, Adelia J. A. Aquino, Edward L. Quitevis
Summary: The study presented in the paper utilized optical heterodyne-detected Raman-induced Kerr effect spectroscopy (OHD-RIKES) and density functional theory (DFT) to investigate the low-frequency dynamics and picosecond reorientational dynamics of methyl methacrylate (MMA). The results show that the temperature dependence of the reorientational dynamics can be explained by a modified Debye-Stoke-Einstein equation, and the interpretation of the main band of the low-frequency reduced-Raman spectrum of poly(methyl methacrylate) (PMMA) is supported by the Kerr spectrum of MMA. The analysis suggests that the librational motion in PMMA is associated with the torsional motion of the methoxycarbonyl pendant group on the polymer chain.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Physics, Fluids & Plasmas
Kunio Fujiwara, Masahiko Shibahara
Summary: In this study, the heat flux in a solid-liquid interfacial region is obtained in a three-dimensional space at a subatomic spatial resolution based on classical molecular dynamics. The directional qualities of the heat flux are significantly dependent on the subatomic stresses in the structures of condensed phase systems. The properties of stress and energy flux at the subatomic scale are comprehensively investigated to determine the origin of the thermal transport mechanism at the solid-liquid interface.
Article
Thermodynamics
Kgomotso Masilo, Indra Bahadur
Summary: This study investigates the molecular interactions of binary mixtures of acetophenone with carboxylic acids, such as acetic and propionic acid, through the measurement of thermophysical properties. The thermodynamic properties of the binary mixtures are calculated and correlated with the Redlich-Kister polynomial, providing an understanding of the molecular interactions in the mixtures. In addition, the variations of the thermodynamic properties with temperature and acetophenone mole fraction are discussed using FT-IR spectroscopy.
JOURNAL OF CHEMICAL THERMODYNAMICS
(2022)
Article
Chemistry, Physical
Aysha Fatima, Km. Pooja, Sandhya Savita, Meenakshi Singh, Indresh Verma, Nazia Siddiqui, Saleem Javed
Summary: The study focused on the quantum chemical investigation, surface analysis, and NMR experiments of Sulfathiazole (ST), providing insights into its molecular structure, crystal interactions, and optical properties. Results showed that ST is a potent antimicrobial drug with significant implications in the pharmaceutical sector.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Chemistry, Multidisciplinary
Masato Takeuchi, Ryo Kurosawa, Junichi Ryu, Masaya Matsuoka
Summary: The hydration behavior of LiOH, LiOH•H2O, and LiCl was studied using NIR spectroscopy. Anhydrous LiOH slowly hydrated to form LiOH•H2O under ambient conditions, while interlayer OH- and coordinated H2O of LiOH•H2O remained unchanged even when exposed to air. The hydration of LiOH surface did not follow a second-order reaction due to the lack of energy barrier for the chemisorption of H2O molecules onto defect sites. Additionally, hydration of deliquescent LiCl and formation of LiCl solution were successfully observed by NIR spectroscopy.
Article
Multidisciplinary Sciences
Ruishi Qi, Ruochen Shi, Yuehui Li, Yuanwei Sun, Mei Wu, Ning Li, Jinlong Du, Kaihui Liu, Chunlin Chen, Ji Chen, Feng Wang, Dapeng Yu, En-Ge Wang, Peng Gao
Summary: Four-dimensional electron energy-loss spectroscopy measurements reveal localized modes at heterointerfaces that impact thermal conductance and electron mobility. Experimental challenges stem from the need to achieve combined spatial, momentum, and spectral resolutions to probe these modes effectively.
Article
Chemistry, Physical
Aysha Fatima, Ghazala Khanum, Arun Sharma, Km Garima, Sandhya Savita, Indresh Verma, Nazia Siddiqui, Saleem Javed
Summary: Phthalic anhydride was studied spectroscopically using various methods such as NMR, FT-IR, and UV-Visible. The analysis revealed insights into the molecular structure optimization, intermolecular interactions, and charge transfer within the molecule. The results showed good agreement between experimental data and computational results, providing important insights for further drug design research.
JOURNAL OF MOLECULAR STRUCTURE
(2022)
Article
Physics, Multidisciplinary
Chun-Chieh Yu, Takakazu Seki, Yongkang Wang, Mischa Bonn, Yuki Nagata
Summary: This article introduces a noninvasive, polarization-resolved, surface-specific sum-frequency generation spectroscopy that provides quantitative depth information for studying the three-dimensional spatial distribution of molecules at soft matter interfaces. Through demonstrations on formic acid molecules at the air-water interface, the technique's credibility and effectiveness in probing Ångstrom-scale depth profiles are showcased.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
Joscha Hekele, Matthias Linke, Thomas Keller, Jesil Jose, Marvin Hille, Eckart Hasselbrink, Sebastian Schluecker, Peter Kratzer
Summary: A study on the adsorption structure of 4-nitrothiophenol self-assembled monolayers on the Au(111) surface was conducted using both theoretical calculations and experimental spectroscopy, revealing a decreasing tilt angle of molecules towards the surface with decreasing coverage. Additionally, calculations for biphenylthiol and terphenylthiol showed an increase in van der Waals interactions with multiple aromatic rings, leading to a more upright-standing molecular geometry.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Lu Lin, Yiyi Li, Xujin Qin, Changhui Yu, Minghua Liu, Zhen Zhang, Yuan Guo
Summary: In this study, nonlinear optical spectroscopies were used to investigate the structural chirality in Langmuir monolayers composed of dipalmitoylphosphatidylcholine (DPPC). It was found that the chiral response decreased with increasing surface pressure, indicating the presence of chiral superstructures formed by achiral moieties. The chirality of the terminal CH3 groups showed a similar trend as that of the chiral response, while the chirality of the CH2 groups increased monotonically. A racemic DPPC monolayer showed no chiral response from the CH3 groups, but chiral response was observed from the CH2 groups, suggesting that the orientation of interfacial CH2 was independent of the molecular handedness. The results provide insights into the molecular mechanism underlying the structural chirality in DPPC monolayers.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Diana L. Nossa Gonzalez, Jovanny A. Gomez Castano, Carlos A. Franca, Gustavo A. Echeverria, Oscar E. Piro, Mauricio F. Erben
Summary: The synthesis of novel amide compounds with bulky and hydrophilic substituents is reported. These compounds exhibit unique properties due to the combination of steric hindrance and hydrophilicity. Characterization using NMR, IR, and Raman spectroscopy as well as X-ray diffraction analysis reveals their vibrational properties, molecular arrangements, and electronic features. The presence of resonance-assisted hydrogen bonds within the amide core is observed, indicating pi electronic delocalization.
Article
Chemistry, Physical
Yuki Nojima, Shoichi Yamaguchi
Summary: In this study, the presence of weakly hydrogen-bonded water molecules buried in the hydrophobic moiety of charged lipids at aqueous interfaces was confirmed using heterodyne-detected sum frequency generation (HD-SFG) spectra. The chi((3)) contribution was successfully subtracted from the observable, allowing the reconfirmation of the weakly hydrogen-bonded water molecules in the hydrophobic moiety.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Pingsu Ma, Yuan Liu, Xiao Sang, Junjun Tan, Shuji Ye, Liran Ma, Yu Tian
Summary: This study utilizes SFG spectroscopy and AFM to investigate the effect of wetting on underwater friction and finds that a homogeneous interfacial water structure is crucial for achieving low friction.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Yang-Yang Zhang, Chong Wang, Gang Li, Xiangyu Zang, Yong Yu, Han-Shi Hu, Jiayue Yang, Weiqing Zhang, Dongxu Dai, Guorong Wu, Ling Jiang, Xueming Yang, Jun Li
Summary: This study reports the infrared spectra of neutral water heptamer and identifies its structures. The results demonstrate the presence of multiple nearly isoenergetic isomers at finite temperatures. These findings contribute to bridging the gap between the understanding of water hexamer and octamer.
CELL REPORTS PHYSICAL SCIENCE
(2022)
Article
Chemistry, Physical
Florent Goujon, Aziz Ghoufi, Patrice Malfreyt
Summary: The study reveals the presence of a two-dimensional hydrogen bond network in the layer closest to graphene, and quantifies the strengthening of intermolecular interactions in liquids by calculating interface tension with a graphene monolayer.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Kyosuke Isoda, Tatsuya Ishiyama, Yuichiro Mutoh, Daisuke Matsukuma
ACS APPLIED MATERIALS & INTERFACES
(2019)
Article
Chemistry, Physical
Sho Kishinaka, Akihiro Morita, Tatsuya Ishiyama
JOURNAL OF CHEMICAL PHYSICS
(2019)
Article
Chemistry, Physical
Tatsuya Ishiyama, Akihiro Morita
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2019)
Article
Chemistry, Physical
Tatsuya Ishiyama
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Tatsuya Ishiyama, Kazuya Kitanaka
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Chemistry, Physical
Tatsuya Ishiyama
Summary: NE-AIMD simulations were used to study the vibrational energy relaxation path of excited non-hydrogen-bonded OH at an air/water interface. The simulations reproduced experimentally observed features, showing that relaxation time scales of free OH at the surface of pure water and isotopically diluted water are similar. It was found that both stretching vibrational coupling and bend-stretching combination band contribute to the relaxation path of free OH at the surface.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Tatsuya Ishiyama
Summary: The vibrational energy relaxation paths of hydrogen-bonded OH excited in pure water and deuterated water were elucidated through non-equilibrium ab initio molecular dynamics (NE-AIMD) simulations. The simulation showed that the relaxation of excited OH vibration in pure water occurs quickly, while in deuterated water, it relaxes on a longer timescale, consistent with experimental observations. The decomposition of relaxation energies into intramolecular and intermolecular couplings revealed different pathways for relaxation in pure water compared to deuterated water.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Yo-ichi Yamamoto, Tatsuya Ishiyama, Akihiro Morita, Toshinori Suzuki
Summary: The study using EUV photoemission spectroscopy reveals the variation of vertical ionization energy and the energy and shape of individual photoelectron bands in aqueous and methanol solutions. The VIE of liquids changes with solute concentrations, indicating surface dipoles at the gas-liquid interface, while solvents alter the structure of first solvation shell of ionized solvent molecules. Solutes cause changes in high concentration photoelectron spectra, such as changes in band splitting, providing insights into interfacial and solution chemistry.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Nanoscience & Nanotechnology
Ayumi Ikenaga, Yuichi Akiyama, Tatsuya Ishiyama, Masayuki Gon, Kazuo Tanaka, Yoshiki Chujo, Kyosuke Isoda
Summary: A novel room-temperature stimuli-responsive N-heteroacene-based liquid material bearing a chiral alkyl chain was developed, which underwent a disordered-ordered state change in response to HCl vapor to form self-assembled solid structures and trigger circularly polarized luminescence. The synergy between experimental in situ observations and molecular dynamics simulations opens up a new avenue for developing stimuli-responsive materials and discovering novel phenomena in such materials.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Tatsuya Ishiyama
Summary: The article investigates the vibrational energy relaxation dynamics of excited hydrogen-bonded OH at an air/water interface through NE-AIMD simulations, comparing it to the behavior in bulk liquid water. The study shows that the relaxation dynamics of H-bonded OH are highly dependent on the surrounding H-bond environments, especially in isotopically diluted water conditions. In isotopically diluted water, the main relaxation pathway is intramolecular stretch and bend couplings, which are more efficient at the air/water interface due to strong H-bonding interactions.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Nobuhiro Yasoshima, Tatsuya Ishiyama, Makoto Gemmei-Ide, Nobuyuki Matubayasi
Summary: Molecular dynamics simulations reveal that water molecules tend to form hydrogen bonds with the carbonyl oxygen and methoxy oxygen of the PMEA side chains, enhancing the head-to-tail stacking structure. Further penetration of water into the PMEA structure gradually increases water-water hydrogen bonding, promoting the formation of water clusters even below the equilibrium water content.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Chemistry, Physical
Nobuhiro Yasoshima, Tatsuya Ishiyama, Nobuyuki Matubayasi
Summary: The energetics of adsorption on the interfaces of PMEA, PMMA, and PBA with water were studied using all-atom molecular dynamics simulation. The adsorption free energy was found to be favorable for all combinations of solute and polymer, and PMMA exhibited the strongest adsorption for hydrophobic solutes while PMEA showed the strongest adsorption for hydrophilic solutes. The polymer contribution to the adsorption free energy was larger with increasing solute size. The total free energy of adsorption correlated well with the solvation free energy in bulk water for hydrophobic solutes only.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Multidisciplinary
Tatsuya Ishiyama, Tahei Tahara, Akihiro Morita
Summary: This study reveals that incomplete hydrogen bonding to phenol at the air-water interface affects excited states and reduces the reaction barrier, resulting in a facilitated reaction rate compared to bulk water. The dynamics of reactions at interfaces can be substantially different due to differences in the stabilization energy of electronic states in varied solvation environments.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Takashi Iwahashi, Tatsuya Ishiyama, Yasunari Sakai, Akihiro Morita, Doseok Kim, Yukio Ouchi
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2020)
Article
Materials Science, Multidisciplinary
Toshiki Sugimoto, Yuji Otsuki, Tatsuya Ishiyama, Akihiro Morita, Kazuya Watanabe, Yoshiyasu Matsumoto
