Article
Chemistry, Multidisciplinary
Verena Pramhaas, Holger Unterhalt, Hans-Joachim Freund, Guenther Rupprechter
Summary: The surface structure and shape of oxide-supported metal nanoparticles can be determined using polarization-dependent sum-frequency-generation (SFG) spectroscopy. This technique reveals the average surface structure and shape of the nanoparticles and can be used to monitor particle restructuring in situ. It has the potential to be a valuable tool for operando catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Physical
Haoyuan Wang, Wei Xiong
Summary: This review discusses the recent developments and applications of vibrational sum-frequency generation (VSFG) microscopy, highlighting its relationship with traditional spectroscopy, microscopy, and time-resolved measurements. Crucial applications of VSFG microscopy in self-assembled materials were emphasized, revealing hidden relationships between physical properties. The review also touches upon the recent development of ultrafast transient VSFG microscopy, offering spatial measurements of the ultrafast vibrational dynamics of self-assembled materials.
ANNUAL REVIEW OF PHYSICAL CHEMISTRY, VOL 72
(2021)
Article
Optics
Karolis Madeikis, Robertas Kananavicius, Rokas Danilevicius, Audrius Zaukevicius, Regimantas Januskevicius, Andrejus Michailovas
Summary: This work presents the development of a femtosecond tunable mid-IR radiation source for a compact broadband high-resolution SFG spectroscopy system, achieving >5(X)cm(-1) bandwidth widely tunable microjoule level pulses in the mid-IR spectral region. The developed SFG spectrometer demonstrates a unique combination of parameters with excellent spectral resolution and fast simultaneous acquisition of broadband spectra.
Article
Chemistry, Physical
Laura Vietze, Ellen H. G. Backus, Mischa Bonn, Maksim Grechko
Summary: In condensed molecular matter, low-frequency modes play a crucial role in determining thermodynamic parameters and functions, and can be measured directly using two-dimensional terahertz-infrared-visible spectroscopy. However, interference between signals from different excitation pathways may complicate the analysis of spectra.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Harison Rozak, Satoshi Nihonyanagi, Anton Myalitsin, Subhadip Roy, Mohammed Ahmed, Tahei Tahara, Izabela I. Rzeznicka
Summary: The receptor binding domain (RBD) of spike proteins plays a crucial role in the attachment of SARS-CoV-2 to ACE2. Mutations in the spike RBD, such as N501Y, result in higher transmissibility by enhancing the binding with negatively charged ACE2. This study investigates the adsorption of ACE2 and spike (N501Y) RBD at a lipid/water interface and provides insights into their interaction in a lipid matrix.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Lu Lin, Zening Liu, Uvinduni I. Premadasa, Tianyu Li, Ying-Zhong Ma, Robert L. Sacci, John Katsaras, Kunlun Hong, C. Patrick Collier, Jan-Michael Y. Carrillo, Benjamin Doughty
Summary: This study discovers that specific cation effects can modulate the assemblies of hydrophobic tails in cationic amphiphiles at liquid/liquid interfaces. It is demonstrated that small cations, such as Li+, can bind to the oxygen atoms in the hydrophobic tails and pin them to the interface, resulting in a kinked conformation. This finding not only provides a method for controlling molecular assembly at liquid/liquid interfaces, but also offers insights for applications such as Li+ separation in soft-matter electronics.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Youngjin Choi, Hyeng Jin Kim, Eunchan Kim, Huiyeong Kang, Junhyeok Park, Young Rag Do, Kyungwon Kwak, Minhaeng Cho
Summary: Area-selective atomic layer deposition (AS-ALD) of insulating metallic oxide layers can be improved by enhancing the inhibition efficiency of alkanethiol self-assembled monolayers (SAMs) through a discontinuously temperature-controlled ALD technique. Temperature-dependent vibrational sum-frequency-generation spectroscopy reveals that the thermally induced formation of gauche defects in the SAMs deteriorates the inhibition efficiency. By incorporating self-healing and dissipation of thermally induced stress on the SAM structure, 60 ALD cycles (6.6 nm) are achieved, demonstrating the potential of this method to enhance the efficiency of AS-ALD as a nanopatterning technique.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Multidisciplinary Sciences
Deepak Ojha, Thomas D. Kuehne
Summary: In this study, a simple recipe based on narrowband IR pump and broadband vSFG probe technique was used to computationally obtain the two-dimensional vSFG spectrum of water molecules at the air-water interface. The study demonstrated that the vibrational spectral dynamics of the free OH bond is faster than that of the bonded OH mode at the interface.
SCIENTIFIC REPORTS
(2021)
Article
Instruments & Instrumentation
Xinting Liu, Bo-Han Li, Yu Liang, Wen Zeng, Huang Li, Chuanyao Zhou, Zefeng Ren, Xueming Yang
Summary: This article presents a method to generate narrowband picosecond second harmonic (SH) and fundamental frequency (FF) pulses with high-conversion efficiency from a Ti:sapphire femtosecond laser amplifier, and successfully amplifies the pulses through optimization of a nonlinear crystal and an optical parametric amplifier. Additionally, dual-wavelength output, useful for femtosecond stimulated Raman spectroscopy, was achieved.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Chemistry, Multidisciplinary
Thomas P. Gray, Jun Nishida, Samuel C. Johnson, Markus B. Raschke
Summary: This study demonstrates vibrational excitons as a molecular ruler for measuring the delocalization of intermolecular wave functions and nano-domain size in SAMs. By combining experimental measurements and modeling, the domain sizes and distribution of 4-NTP SAM on gold surface were revealed.
Article
Chemistry, Multidisciplinary
Sohyun Park, Eunchan Kim, Youngjin Choi, Jiung Jang, Kyungwon Kwak, Minhaeng Cho, Hyo Jae Yoon
Summary: This study investigated the thermoresponse of odd-even effect in self-assembled monolayers (SAMs) of n-alkanethiolates on template-stripped gold using contact angle goniometry and vibrational sum frequency generation spectroscopy. The results showed that the odd-even effect disappeared upon heating in liquid-like SAMs, indicating increased structural disorder. However, in wax- and solid-like SAMs, opposite thermoresponse was observed for odd and even molecules, mitigating the odd-even effect.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Ruowei Yi, Yayun Mao, Yanbin Shen, Liwei Chen
Summary: Current research in the Li-battery field is focused on developing systems with higher energy density while also addressing safety, stability, and cycling life. Molecular self-assembly is seen as a promising tool in surface chemistry with advantages such as spontaneous organization and molecular-scale uniformity, showing potential in addressing pressing issues in battery research.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
Alexander P. Fellows, Vasileios Balos, Ben John, Alvaro Diaz Duque, Martin Wolf, Martin Thaemer
Summary: Second-order nonlinear spectroscopy is an important technique for studying interfacial systems due to its ability to analyze molecular structures and interactions. This study demonstrates that information about depth distributions, molecular orientation, and local dielectric properties can be extracted from the phase of the measured signal using multiple nonlinear pathways. This novel information can be correlated to characteristic vibrational spectra, enabling advanced sample characterization and analysis of interfacial molecular structures.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Analytical
Tanurup Das, Annapoorni Ammal, Abhimanyu Harshey, Vindresh Mishra, Ankit Srivastava
Summary: Semen is a critical body fluid in sexual assaults, and vibrational spectroscopy has emerged as a valuable tool for its analysis, but practical limitations still exist. Research has focused on identifying, discriminating, and estimating timing since deposition of semen.
MICROCHEMICAL JOURNAL
(2021)
Article
Chemistry, Physical
Daria Maltseva, Grazia Gonella, Jean-Marie Ruysschaert, Mischa Bonn
Summary: Biomembrane hydration is crucial for understanding processes at biological interfaces. While the effect of the lipid headgroup has been extensively studied, the impact of the acyl chain chemical structure on lipid-bound interfacial water has remained elusive. This study explores the influence of acyl tail unsaturation and chain length on the lipid headgroup packing and associated water organization in model membranes. The findings highlight the critical role of acyl chain chemistry in determining both membrane fluidity and hydration.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Tarcius N. Ramos, Benoit Champagne
Summary: The Sequential Quantum Mechanics/Molecular Mechanics scheme was used to systematically investigate the polarizability and first hyperpolarizability at the water-vacuum interface. It was found that the anisotropy of the polarizability increased, and there was an increase in the response of the first hyperpolarizability.
Article
Chemistry, Multidisciplinary
Bethany R. R. Hood, Yovan de Coene, Afonso V. V. Torre Do Vale Froes, Claire F. F. Jones, Pierre Beaujean, Vincent Liegeois, Fraser MacMillan, Benoit Champagne, Koen Clays, John Fielden
Summary: Electrochemically switched 2(nd) order non-linear optical responses have been demonstrated for the first time in polyoxometalates (POMs), with an arylimido-derivative showing a leading combination of high on/off contrast (94 %), high visible transparency, and cyclability.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Francois Mairesse, Lorenzo Maschio, Benoit Champagne
Summary: Using the CRYSTAL17 package, first-principles calculations were conducted to predict the values of chi((2)) for six historical NLO crystals. Various computational aspects were considered to ensure converged results, including lattice summations, k-points, electrostatic interactions, and atomic basis set size. The impact of HF exchange on the chi((2)) tensor components was also investigated.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Charlotte Bouquiaux, Frederic Castet, Benoit Champagne
Summary: The extensive collection of lipids found in cell membranes plays a significant role in the overall structure, dynamics, and properties of the membranes, as well as the biological processes occurring within them. This study focuses on investigating a range of saturated glycerophospholipids with varying headgroup structures using second harmonic generation (SHG) nonlinear optical (NLO) response analysis. The research reveals that the lipidic arrangement is strongly influenced by the hydrophilic head, while the hydrophobic region has less impact. Moreover, the computational approach provides insights into the relationship between lipid building blocks and the NLO responses of the embedded dye.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Organic
Abel Idrice Adjieufack, Benoit Champagne, Vincent Liegeois
Summary: Bonding evolution theory was used to elucidate the reaction mechanism of the intramolecular aza-Wittig reaction. The reaction involves the formation of a cycloadduct, decarboxylation, intramolecular [2+2] cycloaddition, and retro [2+2] cycloaddition. The rate-determining step is the formation of the cycloadduct and the reaction is exergonic, resulting in the formation of the aromatic benzothiazole.
SYNTHESIS-STUTTGART
(2023)
Editorial Material
Chemistry, Multidisciplinary
Tarcius N. Ramos, Benoit Champagne
Summary: This article investigates the interfacial selectivity of second harmonic generation at the water-vacuum interface through combining classical molecular dynamics and quantum chemistry simulations, distinguishing between bulk and interfacial contributions through calculated molecular first hyperpolarizability responses.
Article
Chemistry, Physical
Tarcius N. Ramos, Laura Le Bras, Yves L. Dory, Benoit Champagne
Summary: Targeting the use of second harmonic generation (SHG) as a bioimaging technique, the SHG first hyperpolarizabilities (beta) of assemblies of benzene-1,3,5-tricarboxamide derivatives were evaluated using density functional theory. The calculations revealed that the assemblies exhibit size-dependent SHG responses, with a maximum 18-times increase in beta HRS for B4 when going from monomer to pentamer. The presence of iodine atoms on the phenyl core enhanced the intrinsic SHG responses, and the side chains affected the relative orientation of dipole moment and first hyperpolarizability vectors.
Article
Chemistry, Physical
Andrea Bonvicini, Kayn A. Forbes, David L. Andrews, Benoit Champagne
Summary: This study presents the first computational quantum-chemistry implementation of hyper-Rayleigh scattering optical activity (HRS-OA), a nonlinear chiroptical phenomenon. The equations for simulating the differential scattering ratios of HRS-OA are derived based on the theory of quantum electrodynamics and the interactions of electric dipole, magnetic dipole, and electric quadrupole. Computation results of HRS-OA quantities for a chiral organic molecule (methyloxirane) using a broad range of atomic orbital basis sets are presented and analyzed, demonstrating the ability of HRS-OA to distinguish between enantiomers of the same chiral molecule.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Francois Mairesse, Benoit Champagne
Summary: The quantum treatment of electrons at the Kohn-Sham Density Functional Theory (DFT) level of approximation is used to optimize the structure of four organic and organo-metallic crystalline systems with nonlinear optical properties. The study addresses the lack of London-type interactions description in exchange-correlation functionals (XCFs) by employing the D* scheme, a variation of the D2 correction scaled for crystal solid state interactions. The performance and suitable scaling factors of the D* scheme are demonstrated for four representative XCFs.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2023)
Article
Chemistry, Physical
Komlanvi Sevi Kaka, Pierre Beaujean, Frederic Castet, Benoit Champagne
Summary: Recent measurements of the third harmonic scattering responses of molecules have provided new insights into computing molecular second hyperpolarizabilities (gamma) and deducing structure-property relationships. This paper evaluates the second hyperpolarizability of the pi-nitroaniline molecule using various wavefunction and density functional theory methods. The results show that the MP2 scheme offers the best accuracy/cost ratio for computing static gamma, while density functional theory methods still face challenges in accurately computing gamma. Additionally, the double-hybrid B2-PLYP functional provides accurate estimates of static gamma values.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Andrea Bonvicini, Benoit Champagne
Summary: In this work, the expressions for the third-harmonic scattering optical activity (THS-OA) spectroscopic responses are derived by combining molecular quantum electrodynamics (QED) and response theory, allowing for their computational implementation. The study shows how the pure and mixed second hyperpolarizabilities can be obtained as specific cases of a generic cubic response function, enabling the calculation of THS-OA spectroscopy.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Andrea Bonvicini, Benoit Champagne
Summary: This paper discusses the theoretical formulation and computational procedure of linear and nonlinear molecular spectroscopies applied to isotropic samples. It introduces the concept of rotational averaging of Cartesian tensors and proposes a heuristic computational method for finding linearly independent fundamental isotropic Cartesian tensors.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Carmelo Naim, Raphael Vangheluwe, Isabelle Ledoux-Rak, Benoit Champagne, Claire Tonnele, Mireille Blanchard-Desce, Eduard Matito, Frederic Castet
Summary: The second-order nonlinear optical properties of four series of amphiphilic cationic chromophores have been investigated experimentally and theoretically. The theoretical methodology combining classical molecular dynamics and quantum chemical calculations provides a rational approach for designing SHG dyes based on EFISH measurements. The good agreement between experimental and theoretical results demonstrates the usefulness of this MD + QM scheme.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Charlotte Bouquiaux, Frederic Castet, Benoit Champagne
Summary: Lipid molecules play important roles in cell functions and their structural diversity is related to different fatty acids. The nature of fatty acids has an additive effect on the overall membrane structure. Nonlinear optical responses of an embedded chromophore can be used to study the local structure of cell membranes.
Article
Chemistry, Physical
Charlotte Bouquiaux, Pierre Beaujean, Tarcius N. Ramos, Frederic Castet, Vincent Rodriguez, Benoit Champagne
Summary: The solvent effects on the optical properties of an ANEP dye were studied using experimental and theoretical methods. Experimental measurements showed a decrease in the hyperpolarizablity of the dye in polar solvents, which was confirmed by theoretical calculations using different solvation models.
JOURNAL OF CHEMICAL PHYSICS
(2023)