1
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Nagasaka M. Probing Isolated Water Molecules in Aqueous Acetonitrile Solutions Using Oxygen K-Edge X-ray Absorption Spectroscopy. J Phys Chem Lett 2024:5165-5170. [PMID: 38713030 DOI: 10.1021/acs.jpclett.4c01087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Oxygen K-edge X-ray absorption spectroscopy (XAS) of an aqueous acetonitrile solution exhibited a sharp peak at approximately 537 eV, which was similar to that of water vapor and was not observed in liquid water. The inner-shell spectra of isolated water molecules and water clusters of different sizes surrounded by acetonitrile molecules were obtained by extracting these water structures from the liquid structures of aqueous acetonitrile solutions, as calculated using molecular dynamics simulations. The sharp peak profiles of the O K-edge XAS spectra were derived not from water clusters but from isolated water molecules surrounded by acetonitrile molecules. The present study proposes that isolated water molecules are easily formed in aqueous acetonitrile solutions and that the electronic structures of the isolated water molecules can be analyzed using O K-edge XAS spectra, which separates the contributions of small water clusters.
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Affiliation(s)
- Masanari Nagasaka
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
- Graduate Institute for Advanced Studies, SOKENDAI, Myodaiji, Okazaki 444-8585, Japan
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2
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Zeng YW, He AQ, Yang LM, Ozaki Y, Noda I, Xu YZ. Patterns of Cross-Peaks in Two-Dimensional Correlation Spectra to Probe Intermolecular Interactions Described by Two Reversible Reactions. APPLIED SPECTROSCOPY 2024:37028241245136. [PMID: 38646741 DOI: 10.1177/00037028241245136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Two-dimensional correlation spectroscopy is used to investigate the intermolecular interaction between two substances dissolved in the same solutions, where the intermolecular interaction is described by two reversible reactions producing two supramolecular aggregates. The severe overlappings expected among the characteristic peaks of the original solute and aggregates make conventional one-dimensional spectra difficult to accurately reflect the physiochemical nature of the intermolecular interaction. The double asynchronous orthogonal sample design (DAOSD) approach is utilized to analyze the simulated data for proof-of-principle demonstration. The patterns of cross-peaks are much more complex compared with the intermolecular interaction described by only a single reaction. Four major groups of cross-peaks with characteristic patterns observed in the pair of DAOSD asynchronous spectra are systematically analyzed and classified. Further analysis of the spectral feature of the cross-peaks of the DAOSD asynchronous spectra is helpful to exact additional information concerning the variation of the peak position and peak width of the aggregates compared with those of the original solute. The result is important to reveal the physicochemical nature of intermolecular interaction between the solutes (e.g., changes in conformation, dynamical behavior, etc.). The pattern of cross-peaks in the corresponding 2D asynchronous spectra may become rather complex when the peak position, peak width, and peak intensity of two supramolecular aggregates change simultaneously. Further work using artificial intelligence techniques to interpret the complex cross-peaks is still being carried out.
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Affiliation(s)
- Yi-Wei Zeng
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - An-Qi He
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Li-Min Yang
- State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing, China
| | - Yukihiro Ozaki
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo, Japan
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware, USA
| | - Yi-Zhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
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3
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Xie L, Guo R, Yang L, Ozaki Y, Noda I, Xu Y, Huang K. A new approach to recognizing the correct pattern of cross-peaks from a noisy 2D asynchronous spectrum by detecting intrinsic symmetry via the Kolmogorov-Smirnov test. Phys Chem Chem Phys 2023; 25:12863-12871. [PMID: 37165857 DOI: 10.1039/d2cp05350k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The characteristic cluster pattern of cross-peaks in a 2D asynchronous spectrum provides an effective way to reveal the specific physicochemical nature of subtle spectral changes caused by intermolecular interactions. However, the inevitable presence of noise in the 1D spectra used to construct a 2D asynchronous spectrum is significantly amplified, which poses a serious challenge in identifying the correct cluster pattern of the cross-peaks. While mirror symmetry occurs in some types of cross-peaks, it does not occur in other types. The Kolmogorov-Smirnov test provides a statistical means to check whether the mirror symmetry exists or not between a pair of cross-peaks covered by heavy noise. Thus, different types of cross-peak clusters can be distinguished by excavating intrinsic spectral features from the noisy 2D asynchronous spectrum. The effectiveness of this approach in investigating the nature of intermolecular interactions was showcased in both a simulated model system and a real artemisinin/N-methyl pyrrolidone system.
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Affiliation(s)
- Linchen Xie
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Ran Guo
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
- Beijing CKC, PerkinElmer Inc., Beijing 100015, P. R. China
| | - Limin Yang
- State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, China.
| | - Yukihiro Ozaki
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
- School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
- Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, USA
| | - Yizhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Kun Huang
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
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4
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Xie L, He A, Han J, Wu Y, Li D, Li X, Yang L, Huang K, Ozaki Y, Noda I, Xu Y. Robust Approach to Estimating the Stoichiometric Ratio of Supramolecular Complexes Using the Volume of Cross-Peaks in 2D Asynchronous Spectra and the Jonckheere–Terpstra Test. Anal Chem 2022; 94:15621-15630. [DOI: 10.1021/acs.analchem.2c02332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Linchen Xie
- School of Biology and Medicine, Beijing City University, Beijing 100094, China
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
- State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, China
| | - Anqi He
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Jia Han
- School of Biology and Medicine, Beijing City University, Beijing 100094, China
| | - Yi Wu
- School of Biology and Medicine, Beijing City University, Beijing 100094, China
| | - Da Li
- School of Biology and Medicine, Beijing City University, Beijing 100094, China
| | - Xiaopei Li
- Instrumental Analysis Center, Dalian Polytechnic University, Dalian 116034, PR China
| | - Limin Yang
- State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, China
| | - Kun Huang
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yukihiro Ozaki
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
- School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Yizhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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5
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The Journey of 1-Keto-1,2,3,4-Tetrahydrocarbazole Based Fluorophores: From Inception to Implementation. J Fluoresc 2022; 32:2023-2052. [PMID: 35829843 DOI: 10.1007/s10895-022-03004-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/01/2022] [Indexed: 10/17/2022]
Abstract
Carbazole is a unique template associated with several biological activities. It is due to the diverse and versatile biological properties of carbazole derivatives that they are of immense interest to the research community. 1-keto-1,2,3,4-tetrahydrocarbazoles are important synthetic intermediates to obtain carbazole derivatives. Several members of this family emit fluorescence on photoexcitation. In the context of biochemical and biophysical research, designing and characterising small molecule environment sensitive fluorophores is extremely significant. This article aims to be a state of the art review with synthetic and photophysical details of a variety of fluorophores based on 1-keto-1,2,3,4-tetrahydrocarbazole skeleton.
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6
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He AQ, Yu ZQ, Song J, Yang LM, Xu YZ, Noda I, Ozaki Y. Novel Method for Extracting the Spectrum of a Supramolecular Complex via a Comprehensive Approach Involving Two-Dimensional Correlation Spectroscopy, Genetic Algorithm, and Grid Searching. Anal Chem 2022; 94:2348-2355. [PMID: 35041394 DOI: 10.1021/acs.analchem.1c05209] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A supramolecular complex may be formed by two solutes via a weak intermolecular interaction in a solution. The spectrum of the complex is often inundated by the spectra of the solutes that are not involved in the intermolecular interaction. Herein, a novel spectral analysis approach is proposed to retrieve the spectrum of the supramolecular complex. First, a two-dimensional (2D) asynchronous spectrum is constructed. Then, a genetic algorithm is used to obtain a heuristic spectrum of the supramolecular complex. The heuristic spectrum is a linear combination of the spectrum of the complex and the spectrum of a solute. The coefficients of the linear combination are then obtained, according to which the equilibrium constants are invariant among the sample solutions used to construct the 2D asynchronous spectrum. We have applied the approach to a supramolecular system formed by benzene and I2. In the analysis, several binding models are evaluated, and a benzene molecule interacting with two iodine molecules via halogen bonding turns out to be the only possible model. Hence, the characteristic band of the benzene/I2 supramolecular complex around 1819 cm-1 in the Fourier transform infrared (FTIR) spectrum and the corresponding equilibrium constant are obtained. The above results indicate that the novel approach provides a chance to get new insight into various intermolecular interactions studied by spectroscopy.
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Affiliation(s)
- An-Qi He
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, P. R. China.,Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China.,Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Zhen-Qiang Yu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, P. R. China.,Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China
| | - Jun Song
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China
| | - Li-Min Yang
- State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, P. R. China
| | - Yi-Zhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.,Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Yukihiro Ozaki
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.,School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
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7
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Cao X, Xing L, Wang Y, Wang S, Sun C, Men Z. Determination of temperature-dependent Fermi resonance in acetonitrile-water binary solution by two-dimensional correlation Raman spectroscopy. J Chem Phys 2021; 155:124302. [PMID: 34598585 DOI: 10.1063/5.0060969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Acetonitrile (AN), as an organic solvent, has a wide range of applications. The C≡N stretching vibration mode (ν2) and the combination mode (ν3 + ν4) are coupled by Fermi resonance (FR). In this work, the phase transition and the interaction mechanism of the 60% AN-water binary solution (AN-Water) were analyzed by calculating FR parameters and two-dimensional correlation Raman spectroscopy (2DCRS). The change in the ν2 band and the base bands ν3 and ν4 caused energy transfer by anharmonic interaction, which led to a change in FR parameters. With a reduced temperature, the energy transfer was caused by microheterogeneity and the energy transfer effect (293-273 K), the phase separation (263-233 K), and the phase transition of AN (223-173 K). The 2DCRS and Gaussian deconvolution provided more information on FR, which revealed the interaction mechanism of the Fermi doublet. The polarity and binding modes of molecules provided a new perspective for analyzing the transmission of electrons and ions in the electrolyte at different temperatures.
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Affiliation(s)
- Xianwen Cao
- Coherent Light and Atomic and Molecular Spectroscopy Laboratory, College of Physics, Jilin University, Changchun 130012, China
| | - Lu Xing
- Coherent Light and Atomic and Molecular Spectroscopy Laboratory, College of Physics, Jilin University, Changchun 130012, China
| | - Ying Wang
- Coherent Light and Atomic and Molecular Spectroscopy Laboratory, College of Physics, Jilin University, Changchun 130012, China
| | - Shenghan Wang
- Coherent Light and Atomic and Molecular Spectroscopy Laboratory, College of Physics, Jilin University, Changchun 130012, China
| | - Chenglin Sun
- Key Laboratory of Physics and Technology for Advanced Batteries, College of Physics, Jilin University, Changchun 130012, China
| | - Zhiwei Men
- Coherent Light and Atomic and Molecular Spectroscopy Laboratory, College of Physics, Jilin University, Changchun 130012, China
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8
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Nagasaka M, Kosugi N. Soft X-ray Absorption Spectroscopy for Observing Element-specific Intermolecular Interaction in Solution Chemistry. CHEM LETT 2021. [DOI: 10.1246/cl.200938] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Masanari Nagasaka
- Institute for Molecular Science, Myodaiji, Okazaki, Aichi 444-8585, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Nobuhiro Kosugi
- Institute for Molecular Science, Myodaiji, Okazaki, Aichi 444-8585, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Myodaiji, Okazaki, Aichi 444-8585, Japan
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9
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Li K, Zhou F, He A, Guo R, Li X, Xu Y, Noda I, Ozaki Y, Wu J. Intensity Enhancement of a Two-Dimensional Asynchronous Spectrum Without Noise Level Fluctuation Escalation Using a One-Dimensional Spectra Sequence Change. APPLIED SPECTROSCOPY 2021; 75:422-433. [PMID: 33103490 DOI: 10.1177/0003702820971714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Previously, we demonstrated that the intensities of cross-peaks in a two-dimensional asynchronous spectrum could be enhanced using sequence change of the corresponding one-dimensional spectra. This unusual approach becomes useful when the determination of the sequential order of physicochemical events is not essential. However, it was not known whether the level of noise in the two-dimensional asynchronous spectrum was also escalated as the sequence of one-dimensional spectra changed. We first investigated the noise behavior in a two-dimensional asynchronous spectrum upon changing the sequence of the corresponding one-dimensional spectra on a model system. In the model system, bilinear data from a chromatographic-spectroscopic experiment on a mixture containing two components were analyzed using a two-dimensional asynchronous spectrum. The computer simulation results confirm that the cross-peak intensities in the resultant a two-dimensional asynchronous spectrum were indeed enhanced by more than 100 times as the sequence of one-dimensional spectra changed, whereas the fluctuation level of noise, reflected by the standard deviation of the value of a two-dimensional asynchronous spectrum at a given point, was almost invariant. Further analysis on the model system demonstrated that the special mathematical property of the Hilbert-Noda matrix (the modules of all column vectors of the Hilbert-Noda matrix being a near constant) accounts for the moderate variation of the noise level during the changes of the sequence of one-dimensional spectra. Next, a realistic example from a thermogravimetry-Fourier transform infrared spectroscopy experiment with added artificial noise in seven one-dimensional spectra was studied. As we altered the sequence of the seven FT-IR spectra, the variation of the cross-peak intensities covered four orders of magnitude in the two-dimensional asynchronous spectra. In contrast, the fluctuation of noise in the two-dimensional asynchronous spectra was within two times. The above results clearly demonstrate that a change in the sequence of one-dimensional spectra is an effective way to improve the signal-to-noise level of the two-dimensional asynchronous spectra.
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Affiliation(s)
- Kaili Li
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing, China
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, 12465Peking University, Beijing, China
| | - Fengshan Zhou
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing, China
| | - Anqi He
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, 12465Peking University, Beijing, China
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, China
| | - Ran Guo
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, 12465Peking University, Beijing, China
- Jiangsu JITRI Molecular Engineering Inst. Co., Ltd, Suzhou, China
| | - Xiaopei Li
- Instrumental Analysis Center, 12400Dalian Polytechnic University, Dalian, China
| | - Yizhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, 12465Peking University, Beijing, China
- Jiangsu JITRI Molecular Engineering Inst. Co., Ltd, Suzhou, China
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, 12465Peking University, Beijing, China
- Department of Materials Science and Engineering, University of Delaware, Newark, DE, USA
| | - Yukihiro Ozaki
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, 12465Peking University, Beijing, China
- Department of Chemistry, School of Science and Technology, 12907Kwansei Gakuin University, Hyogo, Japan
| | - Jinguang Wu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, 12465Peking University, Beijing, China
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10
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Ni L, Zhao J, Song H, Zhang Z, Feng J, Xu Y, Noda I. Application of two-dimensional correlation fluorescence spectroscopy to detect the presence of trace amount of substances. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 237:118374. [PMID: 32334325 DOI: 10.1016/j.saa.2020.118374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/10/2020] [Accepted: 04/14/2020] [Indexed: 06/11/2023]
Abstract
Although fluorescence spectroscopy is a highly sensitive method, it is still rather difficult to identify a minor fluorescent component whose fluorescent peak is overlapped and masked by a dominant fluorescent component in a sample solution. Herein, we describe a two-dimensional correlation spectroscopy (2D-COS) approach based on the Kasha's rule to solve the above common problem. We initially suppose that a sample solution contains the major component only, and the spectral behavior of the major component obeys the Kasha's rule. Then, the shapes of emission spectra obtained under excitation lights of different wavelengths remain invariant. Under this condition, the introduction of a minor fluorescent component can be reflected by the changes on the shapes of emission peaks in the series of emission spectra. Moreover, subtle changes, which are difficult to be found in the original spectra, can be clearly visualized as cross peaks in 2D asynchronous spectrum constructed using a series of emission spectra. In addition, we demonstrate that the intensities of cross peaks can be enhanced by changing the sequence of the series of emission spectra. We utilize the approach on an aqueous solution containing eosin Y and a trace amount of bromocresol green. The presence of bromocresol green with the concentration as low as 400 nM can be revealed via the cross peaks in the resultant 2D asynchronous spectra. In a preliminary study, we suggest that 2D disrelation spectrum might provide an alternative chance to reveal the presence of small amount bromocresol green.
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Affiliation(s)
- Lei Ni
- School of Life Science and Technology, University of Electronic Science and Technology, Chengdu, Sichuan 610054, PR China; Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Jiangsu JITRI Molecular Engineering Inst. Co., Ltd., Suzhou, Jiangsu 215500, PR China
| | - Jiaojiao Zhao
- School of Life Science and Technology, University of Electronic Science and Technology, Chengdu, Sichuan 610054, PR China
| | - Honghong Song
- School of Life Science and Technology, University of Electronic Science and Technology, Chengdu, Sichuan 610054, PR China; Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Zhuoyue Zhang
- School of Life Science and Technology, University of Electronic Science and Technology, Chengdu, Sichuan 610054, PR China
| | - Juan Feng
- School of Life Science and Technology, University of Electronic Science and Technology, Chengdu, Sichuan 610054, PR China.
| | - Yizhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Jiangsu JITRI Molecular Engineering Inst. Co., Ltd., Suzhou, Jiangsu 215500, PR China.
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, United States
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11
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Nagasaka M, Yuzawa H, Kosugi N. Microheterogeneity in Aqueous Acetonitrile Solution Probed by Soft X-ray Absorption Spectroscopy. J Phys Chem B 2020; 124:1259-1265. [PMID: 31990199 DOI: 10.1021/acs.jpcb.0c00551] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chemical processes in solution are influenced by microheterogeneity (MH), where two liquids seem to be mixed in a macroscopic scale but are microscopically inhomogeneous. We have investigated one of the simplest MH systems, aqueous acetonitrile solution, using soft X-ray absorption spectroscopy (XAS). Molecular interactions of acetonitrile were revealed by C and N K-edge XAS at different concentrations, and those of solvent water were separately revealed by O K-edge XAS. The energy shift of the C≡N π* peak at the C K-edge shows three characteristic concentration regions and a phase-transition-like behavior between them. By comparing the energy shifts in XAS spectra with ab initio quantum chemical inner-shell calculations, we have determined local structures of acetonitrile-water mixtures in three concentration regions and found that the dipole interaction between acetonitrile and water is the key structure to emerge the MH state in the middle concentration region.
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Affiliation(s)
- Masanari Nagasaka
- Institute for Molecular Science , Myodaiji, Okazaki 444-8585 , Japan.,SOKENDAI (The Graduate University for Advanced Studies) , Myodaiji, Okazaki 444-8585 , Japan
| | - Hayato Yuzawa
- Institute for Molecular Science , Myodaiji, Okazaki 444-8585 , Japan
| | - Nobuhiro Kosugi
- Institute for Molecular Science , Myodaiji, Okazaki 444-8585 , Japan.,SOKENDAI (The Graduate University for Advanced Studies) , Myodaiji, Okazaki 444-8585 , Japan
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12
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Zhang Y, Guo R, Li GX, Ling XF, Noda I, Xu Y. Investigation on the interaction between theophylline and alkaline substances using the DAOSD approach. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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13
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Li X, Zeng Y, Deng G, Xu Y, Ozaki Y, Noda I, Wu J. A Novel Approach Based on Two-Dimensional Correlation Spectroscopy to Determine the Stoichiometric Ratio of Two Substances Involved in Intermolecular Interactions. APPLIED SPECTROSCOPY 2019; 73:1051-1060. [PMID: 30990062 DOI: 10.1177/0003702819841625] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A novel technique called AOSD@Job's, combining asynchronous orthogonal sample design scheme (AOSD) with Job's method, is proposed to estimate the stoichiometric ratio of two substances that form a supramolecular aggregate under intermolecular interactions. First, a mathematical analysis was performed along with the procedure of the AOSD@Job's method. Then, the validity of the AOSD@Job's method was manifested by computer simulation on two model systems. Finally, the AOSD@Job's method was applied on two real chemical systems. The stoichiometric ratio between the coordination complex of Ni2+ and ethylenediaminetetraacetic acid disodium salt (EDTA) was estimated to be 1.0. Benzyl alcohol (BA) and β-cyclodextrin (β-CD) were determined to form a 1 : 1 host-guest complex. These values were consistent with the values reported in the literature. Compared with the traditional Job's method, the AOSD@Job's method has an evident advantage since it is still valid even if all the peaks of the supramolecular aggregate severely overlap with the peaks of the substances that form the aggregate.
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Affiliation(s)
- Xiaopei Li
- Instrumental Analysis Center, Dalian Polytechnic University, Dalian, China
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Yiwei Zeng
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Gang Deng
- College of Biological Engineering, Dalian Polytechnic University, Dalian, China
| | - Yizhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Yukihiro Ozaki
- Instrumental Analysis Center, Dalian Polytechnic University, Dalian, China
- Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo, Japan
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Department of Materials Science and Engineering, University of Delaware, Newark, DE, USA
| | - Jinguang Wu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
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14
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Cao X, Gong N, Zhao H, Li Z, Sun C, Men Z. Raman spectroscopic study of nonlinear modulation on Fermi resonance of acetonitrile by hydrogen-bonding network. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.02.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Bao YN, Zeng YW, Guo R, Ablikim M, Shi HF, Yang LM, Yang ZL, Xu YZ, Noda I, Wu JG. Two-dimensional correlation spectroscopic studies on coordination between organic ligands and Ni 2+ ions. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 197:126-132. [PMID: 29449087 DOI: 10.1016/j.saa.2017.12.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 11/27/2017] [Accepted: 12/05/2017] [Indexed: 06/08/2023]
Abstract
3A2g→3T1g(P) transition band of Ni2+ is used to probe the coordination of Ni2+. Two-dimensional asynchronous spectra (2DCOS) are generated using the Double Asynchronous Orthogonal Sample Design (DAOSD), Asynchronous Spectrum with Auxiliary Peaks (ASAP) and Two-Trace Two-Dimensional (2T2D) approaches. Cross peaks relevant to the 3A2g→3T1g(P) transition band of Ni2+ are utilized to probe coordination between Ni2+ and various ligands. We studied the spectral behavior of the 3A2g→3T1g(P) transition band when Ni2+ is coordinated with ethylenediaminetetraacetic acid disodium salt (EDTA). The pattern of cross peaks in 2D asynchronous spectrum demonstrates that coordination brings about significant blue shift of the band. In addition, the absorptivity of the band increases remarkably. The interaction between Ni2+ and galactitol is also investigated. Although no clearly observable change is found on the 3A2g→3T1g(P) transition band when galactitol is introduced, the appearance of cross peak in 2D asynchronous spectrum demonstrates that coordination indeed occurs between Ni2+ and galactitol. Furthermore, the pattern of cross peak indicates that peak position, bandwidth and absorptivity of the 3A2g→3T1g(P) transition band of Ni(galactitol)x2+ is considerably different from those of Ni(H2O)62+. Thus, 2DCOS is helpful to reveal subtle spectral variation, which might be helpful in shedding light on the physical-chemical nature of coordination.
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Affiliation(s)
- Ya-Nan Bao
- School of Materials Science and Engineering, Liaoning Technical University, Fuxin, Liaoning 123000, PR China
| | - Yi-Wei Zeng
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Ran Guo
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Mesude Ablikim
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Hai-Fang Shi
- School of Materials Science and Engineering, Liaoning Technical University, Fuxin, Liaoning 123000, PR China.
| | - Li-Min Yang
- State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, PR China
| | - Zhan-Lan Yang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Yi-Zhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, United States
| | - Jin-Guang Wu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
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16
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He A, Kang X, Xu Y, Noda I, Ozaki Y, Wu J. Investigation on intermolecular interaction between berberine and β-cyclodextrin by 2D UV-Vis asynchronous spectra. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 185:343-348. [PMID: 28601038 DOI: 10.1016/j.saa.2017.05.070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/27/2017] [Accepted: 05/29/2017] [Indexed: 06/07/2023]
Abstract
The interaction between berberine chloride and β-cyclodextrin (β-CyD) is investigated via 2D asynchronous UV-Vis spectrum. The occurrence of cross peaks around (420nm, 420nm) in 2D asynchronous spectrum reveals that specific intermolecular interaction indeed exists between berberine chloride and β-CyD. In spite of the difficulty caused by overlapping of cross peaks, we manage to confirm that the 420nm band of berberine undergoes a red-shift, and its bandwidth decreases under the interaction with β-CyD. The red-shift of the 420nm band that can be assigned to n-π* transition indicates the environment of berberine becomes more hydrophobic. The above spectral behavior is helpful in understanding why the solubility of berberine is enhanced by β-CyD.
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Affiliation(s)
- Anqi He
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Ninghai Doubly Advanced Material Co, Ltd., Ninghai 315602, PR China; Department of Chemistry, School of Science, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
| | - Xiaoyan Kang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Yizhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Ninghai Doubly Advanced Material Co, Ltd., Ninghai 315602, PR China.
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, United States
| | - Yukihiro Ozaki
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Department of Chemistry, School of Science, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
| | - Jinguang Wu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
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17
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Mariani A, Caminiti R, Ramondo F, Salvitti G, Mocci F, Gontrani L. Inhomogeneity in Ethylammonium Nitrate-Acetonitrile Binary Mixtures: The Highest "Low q Excess" Reported to Date. J Phys Chem Lett 2017. [PMID: 28651052 DOI: 10.1021/acs.jpclett.7b01244] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The binary mixtures of the ionic liquid ethylammonium nitrate with acetonitrile have been studied by means of wide- and small-angle X-ray scattering and via two different computational methods, namely, classical molecular dynamics and DFT. The recently debated odd feature in the extreme low q region of some ionic liquid-based binary mixtures is linked to density fluctuations within the system. We show how the "low q excess" is due to some nanoscopic objects which are formed at certain compositions. These structures have different density with respect to the surrounding, thus generating the feature observed. Our results also show how the local arrangement is directly linked to the long-range structure. Moreover, we found once again a similarity in the physicochemical behavior of ethylammonium nitrate and water.
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Affiliation(s)
- Alessandro Mariani
- Dipartimento di Chimica, La Sapienza Università di Roma , Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Ruggero Caminiti
- Dipartimento di Chimica, La Sapienza Università di Roma , Piazzale Aldo Moro 5, 00185 Rome, Italy
- Centro di Ricerca per le Nanotecnologie Applicate all'Ingegneria, Laboratorio per le Nanotecnologie e le Nanoscienze, La Sapienza Università di Roma , Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Fabio Ramondo
- Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell'Aquila , Via Vetoio, L'Aquila I-67100, Italy
| | - Giovanna Salvitti
- Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell'Aquila , Via Vetoio, L'Aquila I-67100, Italy
| | - Francesca Mocci
- Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari , S.S. 554 Km 4,500, I-09042 Monserrato, Italy
| | - Lorenzo Gontrani
- Dipartimento di Chimica, La Sapienza Università di Roma , Piazzale Aldo Moro 5, 00185 Rome, Italy
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18
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Zhang J, Guo R, He A, Weng S, Gao X, Xu Y, Noda I, Wu J. Investigation on the relationship between solubility of artemisinin and polyvinylpyrroli done addition by using DAOSD approach. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 182:136-142. [PMID: 28414978 DOI: 10.1016/j.saa.2017.03.062] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/26/2017] [Accepted: 03/28/2017] [Indexed: 06/07/2023]
Abstract
In this work, we investigated the influence of polyvinylpyrrolidone (PVP) on the solubility of artemisinin in aqueous solution by using quantitative 1H NMR. Experimental results demonstrate that about 4 times of incremental increase occurs on the solubility of artemisinin upon introducing PVP. In addition, dipole-dipole interaction between the ester group of artemisinin and the amide group of N-methylpyrrolidone (NMP), a model compound of PVP, is characterized by two-dimensional (2D) correlation FTIR spectroscopy with the DAOSD (Double Asynchronous Orthogonal Sample Design) approach developed in our previous work. The observation of cross peaks in a pair of 2D asynchronous spectra suggests that dipole-dipole interaction indeed occurs between the ester group of artemisinin and amide group of NMP. Moreover, the pattern of cross peaks indicates that the carbonyl band of artemisinin undergoes blue-shift while the bandwidth and absorptivity increases via interaction with NMP, and the amide band of NMP undergoes blue-shift while the absorptivity increases via interaction with artemisinin. Dipole-dipole interaction, as one of the strongest intermolecular interaction between artemisinin and excipient, may play an important role in the enhancement of the solubility of artemisinin in aqueous solution.
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Affiliation(s)
- Jin Zhang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Shenyang 110032, PR China
| | - Ran Guo
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Key Laboratory of Optoelectronic Devices and System of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, PR China; College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China
| | - Anqi He
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Ninghai Doubly Advanced Materials Co., Ltd., Ninghai 315602, PR China
| | - Shifu Weng
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Xiuxiang Gao
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Yizhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Ninghai Doubly Advanced Materials Co., Ltd., Ninghai 315602, PR China.
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Jinguang Wu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
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19
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Kang X, He A, Guo R, Chen J, Zhai Y, Xu Y, Noda I, Wu J. Investigation on intermolecular interaction between two solutes where one solute occurs in two states. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2015.12.047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Investigation on the spectral properties of 2D asynchronous fluorescence spectra generated by using variable excitation wavelengths as a perturbation. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2016.01.047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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21
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Investigation on the intermolecular interaction between diethyl ether and dichloromethane in gaseous phase by using the DAOSD approach. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2015.12.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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A simplified concentration series to produce a pair of 2D asynchronous spectra based on the DAOSD approach. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2016.02.064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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23
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Li X, He A, Huang K, Liu H, Zhao Y, Wei Y, Xu Y, Noda I, Wu J. Two-dimensional asynchronous spectrum with auxiliary cross peaks in probing intermolecular interactions. RSC Adv 2015. [DOI: 10.1039/c5ra16062f] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A new approach called “asynchronous spectrum with auxiliary peaks (ASAP)” is proposed for generating a 2D asynchronous spectrum to investigate the intermolecular interaction between two solutes (P and Q) dissolved in the same solution.
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Affiliation(s)
- Xiaopei Li
- Institute of Process Engineering
- Chinese Academy of Sciences
- P. R. China
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory for Rare Earth Materials Chemistry and Applications
| | - Anqi He
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory for Rare Earth Materials Chemistry and Applications
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
| | - Kun Huang
- Institute of Process Engineering
- Chinese Academy of Sciences
- P. R. China
| | - Huizhou Liu
- Institute of Process Engineering
- Chinese Academy of Sciences
- P. R. China
| | - Ying Zhao
- Institute of Chemistry
- Chinese Academy of Sciences
- P. R. China
| | - Yongju Wei
- College of Chemistry and Material Science
- Hebei Normal University
- Shijiazhuang
- P. R. China
| | - Yizhuang Xu
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory for Rare Earth Materials Chemistry and Applications
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory for Rare Earth Materials Chemistry and Applications
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
| | - Jinguang Wu
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory for Rare Earth Materials Chemistry and Applications
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
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24
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Liu J, Gao Y, Zheng L, Gao D, He A, Liu Y, Weng S, Zhao Y, Yang Z, Yang L, Wen X, Xu Y, Noda I, Wu J. Coordination between cobalt (II) ion and carbonyl group in acetone probed by using DAOSD approach. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2014.02.036] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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25
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Bi Q, Chen J, Li X, Shi JJ, Guo R, Zhai Y, Xu Y, Noda I, Wu J. A method based on the DAOSD approach to estimate the variation of the peak position and bandwidth caused by intermolecular interactions. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2014.02.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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26
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Characterization of the coordination between Nd3+ and ester groups by using double asynchronous orthogonal sample design approach. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2014.03.047] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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27
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Sonnleitner T, Nikitina V, Nazet A, Buchner R. Do H-bonds explain strong ion aggregation in ethylammonium nitrate + acetonitrile mixtures? Phys Chem Chem Phys 2014; 15:18445-52. [PMID: 24002527 DOI: 10.1039/c3cp51773j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Binary mixtures of the protic ionic liquid ethylammonium nitrate (EAN) and acetonitrile (AN) were studied at 25 °C over the entire composition range by means of broadband dielectric spectroscopy covering 0.2 ≤ ν/GHz ≤ 89. The dielectric spectra could be decomposed into two relaxation processes, both of which proved to be composite modes. For dilute solutions the higher-frequency Debye relaxation centered at ∼60 GHz is associated with the rotational diffusion of AN molecules, whereas at higher salt concentrations ultra-fast intermolecular vibrations and librations of EAN dominate the process. For EAN-rich solutions the lower-frequency relaxation is mainly due to jump reorientation of the ethylammonium cation, whereas contact ion pairs (CIPs) dominate this mode for dilute solutions. From the relaxation amplitudes effective solvation numbers and ion-pair concentrations were determined. For vanishing EAN mole fraction, xEAN → 0, an effective cation solvation number of ∼7 was found which steeply drops until xEAN ≈ 0.2 but shows only moderate decrease later on. The obtained association constant for EAN, K0(A) = 970 L mol(-1), exceeds that of other 1 : 1 electrolytes in AN by a factor of ∼30-50. This observation, as well as the fact that CIPs are formed despite strong cation solvation, indicates that ion pairing is mainly driven by the formation of strong hydrogen bonds between anions and cations.
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Affiliation(s)
- Thomas Sonnleitner
- Institute of Physical and Theoretical Chemistry, Universität Regensburg, 93053 Regensburg, Germany.
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28
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Xu C, Jia X, Xu R, Wang Y, Zhou Q, Sun S. Rapid discrimination of Herba Cistanches by multi-step infrared macro-fingerprinting combined with soft independent modeling of class analogy (SIMCA). SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 114:421-431. [PMID: 23792237 DOI: 10.1016/j.saa.2013.05.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 05/07/2013] [Accepted: 05/09/2013] [Indexed: 06/02/2023]
Abstract
Herba Cistanche, an important Chinese herbal medicine, has common four species, Cistanche deserticola (CD), Cistanche tubulosa (CT), Cistanche salsa (CS) and Cistanche sinensis (CSN) which have been frequent mixed used. To clarify the sources of Herba Cistanches and ensure the clinical efficacy and safety, a method combing IR macro-fingerprinting with statistical pattern recognition was developed to analyze and discriminate the four species of Herba Cistanche. By comparing FT-IR, second derivative spectral fingerprints via group-peak matching, the similarity to CD and total saccharides (TS) followed an increasing sequence, CT<CSN<CS<CD, whereas that to total glycosides (TG) followed a decreasing order, CT>CSN>CS>CD. Characteristic fingerprints of their 2D-IR correlation spectra in 1750-1000 cm(-1) have confirmed the above findings in a more intuitive way. In terms of sources for phenylethanoid glycosides (PhGs), CT can be an ideal alternative species. However, in terms of using them as a whole, more pharmacological study should be conducted due to the different ratios of their chemical constituents, which is also applicable to CSN and CS. Moreover, the four species (179 samples) has been objectively classified by SIMCA based on IR macro-fingerprints.
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Affiliation(s)
- Changhua Xu
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Analysis Center, Tsinghua University, Beijing 100084, China.
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29
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Sigalov MV, Kalish N, Carmeli B, Pines D, Pines E. Probing Small Protonated Water Clusters in Acetonitrile Solutions by 1H NMR. ACTA ACUST UNITED AC 2013. [DOI: 10.1524/zpch.2013.0399] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract
In a previous publication by Kalish et al. (J. Phys. Chem. A 115 (2011) 4063) the existence of well defined small protonated water clusters in acetonitrile has been established by IR spectroscopy. Here we report on a 1H NMR study of triflic acid, CF3SO3H, in acetonitrile-water solutions. Using NMR we are able to corroborate the general solvation scheme we have proposed for the hydrated proton in acetonitrile as a function of the molar ratio between the strong mineral acid and water, n = [H2O]/[acid]. According to this scheme, backed now by both IR absorption spectroscopy and NMR measurements, the very strong triflic acid completely dissociates in acetonitrile/water solutions to yield the aqueous proton and the triflate anion when n > 1. Furthermore, increasing n results in the proton solvated in increasingly larger water clusters formed within the acetonitrile solution.
Clearly distinguishable by NMR are the smallest protonated water clusters, the protonated water monomer, H3
+O, and the protonated water dimer, H5
+O2, which dominate the solution for n = 1,2,3. For larger n the NMR study indicates the gradual increase of the average protonated water cluster size as a function of n while the proton inner solvation core more closely retaining the characteristics of a deformed protonated water dimer, (H2O-H+⋯OH2)
s
than that of the protonated water monomer (H3
+O)
s
.
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Affiliation(s)
- Mark V. Sigalov
- Ben-Gurion University of the Negev, Department of Chemistry, Beer-Sheva 84125, Israel
| | - Noah Kalish
- Ben-Gurion University of the Negev, Department of Chemistry, Beer-Sheva 84125, Israel
| | - Benny Carmeli
- Ben-Gurion University of the Negev, Department of Chemistry, Beer-Sheva 84125, Israel
| | - Dina Pines
- Ben-Gurion University of the Negev, Department of Chemistry, Beer-Sheva 84125, Israel
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30
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Zhang S, Zhang Y, Ma X, Lu L, He Y, Deng Y. Benzonitrile as a Probe of Local Environment in Ionic Liquids. J Phys Chem B 2013; 117:2764-72. [DOI: 10.1021/jp312251q] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shiguo Zhang
- Center for Green Chemistry and Catalysis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Yan Zhang
- Center for Green Chemistry and Catalysis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Xiangyuan Ma
- Center for Green Chemistry and Catalysis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Liujin Lu
- Center for Green Chemistry and Catalysis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Yude He
- Center for Green Chemistry and Catalysis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Youquan Deng
- Center for Green Chemistry and Catalysis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
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31
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Improvement of the sensitivity of the two-dimensional asynchronous spectroscopy based on the AOSD approach by using a modified reference spectrum. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.08.050] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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32
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Marcus Y. The structure of and interactions in binary acetonitrile + water mixtures. J PHYS ORG CHEM 2013. [DOI: 10.1002/poc.3056] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yizhak Marcus
- Institute of Chemistry; The Hebrew University of Jerusalem; Jerusalem; 91904; Israel
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33
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Chen J, Bi Q, Liu S, Li X, Liu Y, Zhai Y, Zhao Y, Yang L, Xu Y, Noda I, Wu J. Double Asynchronous Orthogonal Sample Design Scheme for Probing Intermolecular Interactions. J Phys Chem A 2012; 116:10904-16. [DOI: 10.1021/jp300918g] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Quan Bi
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Shenyang 11660, P. R. China
| | | | | | | | - Yanjun Zhai
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Shenyang 11660, P. R. China
| | | | | | | | - Isao Noda
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United
States
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Kalish NBM, Shandalov E, Kharlanov V, Pines D, Pines E. Apparent stoichiometry of water in proton hydration and proton dehydration reactions in CH3CN/H2O solutions. J Phys Chem A 2011; 115:4063-75. [PMID: 21417385 DOI: 10.1021/jp110873t] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Gradual solvation of protons by water is observed in liquids by mixing strong mineral acids with various amounts of water in acetonitrile solutions, a process which promotes rapid dissociation of the acids in these solutions. The stoichiometry of the reaction XH(+) + n(H(2)O) = X + (H(2)O)(n)H(+) was studied for strong mineral acids (negatively charged X, X = ClO(4)¯, Cl¯, Br¯, I¯, CF(3)SO(3)¯) and for strong cationic acids (uncharged X, X = R*NH(2), H(2)O). We have found by direct quantitative analysis preference of n = 2 over n = 1 for both groups of proton transfer reactions at relatively low water concentrations in acetonitrile. At high water concentrations, we have found that larger water solvates must also be involved in the solvation of the proton while the spectral features already observed for n = 2, H(+)(H(2)O)(2), remain almost unchanged at large n values up to at least 10 M of water.
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Affiliation(s)
- Javier Rodriguez
- Departamento de Física, Comisión Nacional de Energía Atómica, Avenida Libertador 8250, 1429, Buenos Aires, Argentina, ECyT, UNSAM, Martín de Irigoyen 3100, 1650, San Martín, Provincia de Buenos Aires, Argentina, and Departamento de Química Inorgánica, Analítica y Química-Física e INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428, Buenos Aires, Argentina
| | - M. Dolores Elola
- Departamento de Física, Comisión Nacional de Energía Atómica, Avenida Libertador 8250, 1429, Buenos Aires, Argentina, ECyT, UNSAM, Martín de Irigoyen 3100, 1650, San Martín, Provincia de Buenos Aires, Argentina, and Departamento de Química Inorgánica, Analítica y Química-Física e INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428, Buenos Aires, Argentina
| | - Daniel Laria
- Departamento de Física, Comisión Nacional de Energía Atómica, Avenida Libertador 8250, 1429, Buenos Aires, Argentina, ECyT, UNSAM, Martín de Irigoyen 3100, 1650, San Martín, Provincia de Buenos Aires, Argentina, and Departamento de Química Inorgánica, Analítica y Química-Física e INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428, Buenos Aires, Argentina
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New background correction approach based on polynomial regressions for on-line liquid chromatography–Fourier transform infrared spectrometry. J Chromatogr A 2009; 1216:3122-30. [DOI: 10.1016/j.chroma.2009.01.110] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Revised: 01/21/2009] [Accepted: 01/29/2009] [Indexed: 11/20/2022]
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37
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Patterns of cross peaks in 2D synchronous spectrum generated by using orthogonal sample design scheme. J Mol Struct 2008. [DOI: 10.1016/j.molstruc.2008.01.052] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Liu Y, Zhang C, Liu S, Zhao Y, Wang D, Wu J, Xu Y, Noda I. Modified orthogonal sample design scheme to probe intermolecular interactions. J Mol Struct 2008. [DOI: 10.1016/j.molstruc.2007.12.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Qi J, Huang K, Gao X, Li H, Liu S, Zhao Y, Xu Y, Wu J, Noda I. Orthogonal sample design scheme for two-dimensional synchronous spectroscopy: Application in probing lanthanide ions interactions with organic ligands in solution mixtures. J Mol Struct 2008. [DOI: 10.1016/j.molstruc.2008.01.036] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Qi J, Li H, Huang K, Chen H, Liu S, Yang L, Zhao Y, Zhang C, Li W, Wu J, Xu D, Xu Y, Noda I. Orthogonal sample design scheme for two-dimensional synchronous spectroscopy and its application in probing intermolecular interactions. APPLIED SPECTROSCOPY 2007; 61:1359-1365. [PMID: 18198029 DOI: 10.1366/000370207783291993] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This paper introduces a new approach to probing intermolecular interactions based on a framework of two-dimensional (2D) synchronous spectroscopy. Mathematical analysis performed on 2D synchronous spectra using variable concentration as an external perturbation shows that the cross-peaks are composed of two parts. The first part reflects intermolecular interactions that manifest in the form of deviation from the Beer-Lambert law. The second part is related simply to the concentration variations of the solutes and is responsible for the generation of interfering cross-peaks not related to the intermolecular interactions in the system. It is the second part that prevents the reliable identification of intermolecular interactions. We propose a way of selecting the concentrations of solutes so that the resultant dynamic concentration vectors of different solutes become orthogonal to one another. Therefore, the contribution of the second part to the cross-peaks can be effectively removed by the dot product of orthogonal vectors. Our new approach has been tested on a simulated chemical system and a real chemical system. The results demonstrate that interfering cross-peaks can be successfully removed from a 2D synchronous spectrum so that the cross-peaks can be used as a reliable tool to characterize or probe intermolecular interactions.
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Affiliation(s)
- Jian Qi
- College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
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Doubly vibrationally enhanced four wave mixing spectroscopy in an acetonitrile–magnesium perchlorate mixture. J Mol Struct 2006. [DOI: 10.1016/j.molstruc.2006.01.069] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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42
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Azizian S, Shibata K, Matsuda T, Takiue T, Matsubara H, Aratono M. Surface Phase Transition of C12E1 at the Air/Water Interface: A Study by Dynamic Surface Tension, External RA FT-IR, and 2D IR Correlation Methods. J Phys Chem B 2006; 110:17034-42. [PMID: 16927997 DOI: 10.1021/jp063301p] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The surface conformational states of the Gibbs monolayer of ethylene glycol mono-n-dodecyl ether (C(12)E(1)) at the air/water interface was studied using dynamic surface tension, external reflection-absorption FT-IR spectroscopy (ERA FT-IR), and two-dimensional infrared (2D IR) correlation methods at constant temperature. The dynamic surface tensions were measured at different bulk concentrations of C(12)E(1), and it was observed that a constant surface tension region appears at approximately 38.5 mN m(-1) in a dynamic surface tension profile at concentrations higher than 11 micromol kg(-1). This constant surface tension region corresponds to the surface phase transition from liquid expanded (LE) to liquid condensed (LC). Two sets of ERA FT-IR spectra were collected, one at different bulk concentrations but after equilibrium time (equilibrium measurements) and another at constant bulk concentration (m = 16 micromol kg(-1)) but at different times (dynamic measurements). The first set of these measurements show that the peak area increases in the range of 11 < m < or = 16 micromol kg(-1), which means the increase in the number of surfactant molecules at the air/water interface. Also, the wavenumber of antisymmetric CH(2) stretching decreases gradually from approximately 2923 cm(-1) (for 10 and 11 micromol kg(-1)) to approximately 2918 cm(-1) (for m > or = 16 micromol kg(-1)) with increasing concentration. The wavenumbers of 2923 and 2918 cm(-1) were assigned to LE and LC phases, respectively, and the decrease of wavenumber in the concentration range of 11 < m < or = 16 micromol kg(-1) were correlated to the surface phase transition (LE --> LC), or in other words, in the mentioned concentration range, two phases coexist. The dynamic ERA FT-IR measurements at 16 micromol kg(-1) also confirm the surface phase transition from LE to LC. The 2D IR correlation method was applied to the both equilibrium and dynamic IR spectra of the C(12)E(1) monolayer. The synchronous correlation maps show two strong autopeaks at approximately 2922 and approximately 2851 cm(-1) and also show a strong correlation (cross-peaks) between antisymmetric CH(2) stretching (nu(a)) and symmetric CH(2) stretching (nu(s)). The asynchronous correlation maps show that both observed bands of nu(a) and nu(s) in one-dimensional IR split into two components with the characteristic of overlapped bands, which reveals the coexistence of two phases (LE and LC) at the interface at 11 < m < or = 16 micromol kg(-1). The synchronous and asynchronous maps that were obtained from dynamic IR spectra closely resembled the equilibrium map.
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Affiliation(s)
- S Azizian
- Department of Chemistry, Faculty of Sciences, Kyushu University, Hakozaki 6-10-1, Higashiku, Fukuoka 812-8581, Japan.
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Poizat O, Buntinx G, Boilet L. Photoreduction of 4,4‘-Bipyridine by Amines in Acetonitrile−Water Mixtures: Influence of H-Bonding on the Ion-Pair Structure and Dynamics. J Phys Chem A 2005; 109:10813-23. [PMID: 16331924 DOI: 10.1021/jp058199v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The photoreduction of 4,4'-bipyridine (44BPY) by diazabicyclo[2.2.2]octane and triethylamine (TEA) is investigated by using picosecond transient absorption and time-resolved resonance Raman spectroscopy in various acetonitrile-water mixtures. The results are interpreted on the basis of a preferential solvation effect resulting from the presence of a specific interaction between 44BPY and water by hydrogen bonding. Below 10% water, the free 44BPY species is dominant and leads upon photoreduction to a contact ion pair that undergoes efficient intrapair proton transfer if TEA is the amine donor. Above 10% water, most of the 44BPY population is H-bonded and leads upon photoreduction to a hydrated ion pair in which the intrapair proton transfer is inhibited. Instead, the 44BPY(-*) species is protonated by water through the hydrogen bond with a rate constant that increases by more than 3 orders of magnitude on going from 10% to 100% water. The dependence of this rate constant on the solvent mixture composition suggests that the reaction of intracomplex proton transfer is controlled by the hydration of the residual OH(-) species by three molecules of water, leading to a trihydrated HO(-)(H(2)O)(3) species.
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Affiliation(s)
- Olivier Poizat
- Laboratoire de Spectrochimie Infrarouge et Raman, UMR 8516 de l'Université et du CNRS, Centre d'Etudes et de Recherches Lasers et Applications, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France.
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McNavage W, Dai HL. Two-dimensional cross-spectral correlation analysis and its application to time-resolved Fourier transform emission spectra of transient radicals. J Chem Phys 2005; 123:184104. [PMID: 16292896 DOI: 10.1063/1.2074147] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A spectral analysis method, based on the generalized two-dimensional (2D) vibrational spectra correlation analysis, is developed for deciphering the correlation among the spectral peaks of two different spectra. This 2D cross-spectral correlation (2DCSC) analysis is aimed at revealing the vibrational features associated with a common species in two spectra, each obtained from a system containing multiple species with at least one common species. The cross-spectral correlation is based on the premise that the spectral features of the same species should have the same time and frequency responses toward similar perturbations. The effectiveness of the cross-spectral correlation analysis is first illustrated with model systems, with spectral peaks decaying linearly or exponentially with time, before being applied to analyzing time-resolved emission spectra obtained, by a Fourier transform IR spectrometer, for samples consisting of the vibrationally excited transient cyanooxomethyl radical (OCCN). 2DCSC among the three different sets of time-resolved spectra collected following the photodissociation of three different precursor molecules of OCCN, respectively, allows the identification of the CN and CO stretching modes of this radical.
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Affiliation(s)
- William McNavage
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Fillipan N, Bezemer E, Burke J, Rutan SC. Studies of liquid-phase complexes in acetonitrile/water solutions by attenuated total reflection infrared spectroscopy with acetaldehyde as a model solute. APPLIED SPECTROSCOPY 2004; 58:1187-1194. [PMID: 18070399 DOI: 10.1366/0003702042335966] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Chemometric methods combined with infrared (IR) spectroscopy, using attenuated total reflectance (ATR) sampling, are employed here to characterize the stoichiometry of complexes of solvent molecules in the liquid phase. The spectral information provides insight into the liquid microstructure present in liquid chromatographic mobile phases. This information should make it easier to understand and predict the effects of changes in mobile phase composition on the results of chromatographic separations. In this paper, mobile phases consisting of 0 mol % to 100 mol % acetonitrile in water were studied, with the addition of acetaldehyde as a model solute at concentrations ranging from 3 to 8 mol %. Using three-way multivariate curve resolution by the alternating least squares method (MCR-ALS) it was possible to resolve eight unique spectra: four mobile phase components, and four unique spectra of acetaldehyde solvated in different environments. The directions of the shifts of the important acetaldehyde infrared bands show good correlation with those predicted by gas-phase ab initio calculations of small solvated clusters.
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Affiliation(s)
- Nathaniel Fillipan
- Department of Chemistry, Virginia Commonwealth University, P.O. Box 842006 Richmond, Virginia 23284-2006, USA
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46
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Huang CY, Wang T, Gai F. Temperature dependence of the CN stretching vibration of a nitrile-derivatized phenylalanine in water. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(03)00353-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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