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Your search keyword '"Zheng, Ren‐Hui"' showing total 127 results
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127 results on '"Zheng, Ren‐Hui"'

1. Response to "Comment on 'Sum-frequency vibrational spectroscopy of centrosymmetric molecule at interfaces'" [J. Chem. Phys. 160, 107101 (2024)].

Author

Zheng, Ren-Hui, Wei, Wen-Mei, and Zhang, Shuo-Cang

Subjects
*SPECTROMETRY, *MOLECULES, *NONLINEAR optical spectroscopy
Abstract

This article is a response to criticisms raised by Hirano et al. regarding research on sum frequency vibrational spectroscopy (SFVS) of benzene at interfaces. The authors address five points raised in the comment, including the local field effect, symmetry breaking of benzene, and field variations at interfaces. They argue that Hirano et al. underestimated the interfacial EQ SFVS and did not calculate the absolute amplitude of SFVS, which undermines the credibility of their research. The authors' computational SFVS aligns well with experimental results in terms of vibrational frequencies, amplitude, and line shapes, but there are discrepancies in vibrational frequencies and spectral line shapes between their results and the experimental data. [Extracted from the article]

Published
2024
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2. Sum-frequency vibrational spectroscopy of centrosymmetric molecule at interfaces.

Author

Zheng, Ren-Hui, Wei, Wen-Mei, and Zhang, Shuo-Cang

Subjects
*MAGNETIC dipoles, *SPECTROMETRY, *MOLECULES, *QUADRUPOLES, *BENZENE
Abstract

The centrosymmetric benzene molecule has zero first-order electric dipole hyperpolarizability, which results in no sum-frequency vibrational spectroscopy (SFVS) signal at interfaces, but it shows very strong SFVS experimentally. We perform a theoretical study on its SFVS, which is in good agreement with the experimental results. Its strong SFVS mainly comes from the interfacial electric quadrupole hyperpolarizability rather than the symmetry-breaking electric dipole, bulk electric quadrupole, and interfacial and bulk magnetic dipole hyperpolarizabilities, which provides a novel and completely unconventional point of view. [ABSTRACT FROM AUTHOR]

Published
2023
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5. Dual-Emissive Monoruthenium Complexes of N(CH 3)-Bridged Ligand: Synthesis, Characterization, and Substituent Effect.

Author

Wu, Si-Hai, Zhang, Zhe, Zheng, Ren-Hui, Yang, Rong, Wang, Lianhui, Shao, Jiang-Yang, Gong, Zhong-Liang, and Zhong, Yu-Wu

Subjects
RUTHENIUM, ACETONITRILE, OXIDATION-reduction reaction, OXIDATION, X-rays, RUTHENIUM compounds, PYRAZINES
Abstract

Three monoruthenium complexes 1(PF6)2–3(PF6)2 bearing an N(CH3)-bridged ligand have been synthesized and characterized. These complexes have a general formula of [Ru(bpy)2(L)](PF6)2, where L is a 2,5-di(N-methyl-N'-(pyrid-2-yl)amino)pyrazine (dapz) derivative with various substituents, and bpy is 2,2′-bipyridine. The photophysical and electrochemical properties of these compounds have been examined. The solid-state structure of complex 3(PF6)2 is studied by single-crystal X-ray analysis. These complexes show two well-separated emission bands centered at 451 and 646 nm (Δλmax = 195 nm) for 1(PF6)2, 465 and 627 nm (Δλmax = 162 nm) for 2(PF6)2, and 455 and 608 nm (Δλmax = 153 nm) for 3(PF6)2 in dilute acetonitrile solution, respectively. The emission maxima of the higher-energy emission bands of these complexes are similar, while the lower-energy emission bands are dependent on the electronic nature of substituents. These complexes display two consecutive redox couples owing to the stepwise oxidation of the N(CH3)-bridged ligand and ruthenium component. Moreover, these experimental observations are analyzed by computational investigation. [ABSTRACT FROM AUTHOR]

Published
2023
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9. Sum-frequency vibrational spectroscopy of methanol at interfaces due to Fermi resonance.

Author

Zheng, Ren-Hui and Wei, Wen-Mei

Abstract

Sum-frequency nonlinear spectroscopy is a powerful tool in investigating physical and chemical properties at gas/liquid, gas/solid, liquid/liquid and liquid/solid interfaces. Fermi resonance is a well-documented anharmonic phenomenon related to molecular vibrational coupling and the energy transfer phenomenon that exists within and between molecules. Such a phenomenon is widely used in the fields of materials, biology and chemistry. Combining density functional theory and molecular dynamics simulation, we present a method of studying sum-frequency vibrational spectroscopy for the CH3 group of methanol at interfaces due to Fermi resonance. The calculated spectroscopic data agree with the experiment and provide a novel and untraditional point of view with respect to traditional approaches. [ABSTRACT FROM AUTHOR]

Published
2022
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21. Theoretical study on spectral differences of polypeptides constituted by L- and D-amino acids.

Author

Zheng, Ren-Hui, Wei, Wen-Mei, and Liu, Yan-Ying

Subjects
*VIBRATIONAL spectra, *POLYPEPTIDES, *ELECTRONIC spectra, *QUANTUM chemistry, *RAMAN spectroscopy, *EXCITED states
Abstract

Amino acids, polypeptides and proteins, which are all chiral, are the most important living substances. Most living organisms are made up of L-amino acids. Chirality is of great significance in exploring biomolecules. Studying polypeptides with a large number of atoms is a great challenge for quantum chemistry calculation. We conduct structural studies and perform vibrational and electronic spectra investigations on two polypeptides consisting of 14 L- and D-amino acids, both of which are right-handed α-helical. We find that the two polypeptides have similar IR and Raman vibrational spectra except that the polypeptide constituted by D-amino acids has an intramolecular hydrogen bond peak, but their chiral and excited state spectra are different and the chiral spectra are not mirror symmetric, which can be applied to distinguish them and shows that they have different structures in detail. Thus they may have different properties and functions. In addition, the amide III vibrations of the polypeptide include the information of the backbone and side chains. Therefore, care should be taken to apply the amide III vibrations to determine the secondary structure of polypeptide. [ABSTRACT FROM AUTHOR]

Published
2021
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