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García-González F, Otero JC, Ávila Ferrer FJ, Santoro F, Aranda D. Linear Vibronic Coupling Approach for Surface-Enhanced Raman Scattering: Quantifying the Charge-Transfer Enhancement Mechanism. J Chem Theory Comput 2024; 20:3850-3863. [PMID: 38687961 PMCID: PMC11099975 DOI: 10.1021/acs.jctc.4c00061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/12/2024] [Accepted: 04/15/2024] [Indexed: 05/02/2024]
Abstract
The outstanding amplification observed in surface-enhanced Raman scattering (SERS) is due to several enhancement mechanisms, and standing out among them are the plasmonic (PL) and charge-transfer (CT) mechanisms. The theoretical estimation of the enhancement factors of the CT mechanism is challenging because the excited-state coupling between bright plasmons and dark CT states must be properly introduced into the model to obtain reliable intensities. In this work, we aim at simulating electrochemical SERS spectra, considering models of pyridine on silver clusters subjected to an external electric field E⃗ that represents the effect of an electrode potential Vel. The method adopts quantum dynamical propagations of nuclear wavepackets on the coupled PL and CT states described with linear vibronic coupling models parametrized for each E⃗ through a fragment-based maximum-overlap diabatization. By presenting results at different values of E⃗, we show that indeed there is a relation between the population transferred to the CT states and the total scattered intensity. The tuning and detuning processes of the CT states with the bright PLs as a function of the electric field are in good agreement with those observed in experiments. Finally, our estimations for the CT enhancement factors predict values in the order of 105 to 106, meaning that when the CT and PL states are both in resonance with the excitation wavelength, the CT and PL enhancements are comparable, and vibrational bands whose intensity is amplified by different mechanisms can be observed together, in agreement with what was measured by typical experiments on silver electrodes.
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Affiliation(s)
- Francisco García-González
- Andalucía
Tech, Facultad de Ciencias, Departamento de Química Física, Universidad de Málaga, 29071 Málaga, Spain
| | - Juan Carlos Otero
- Andalucía
Tech, Facultad de Ciencias, Departamento de Química Física, Universidad de Málaga, 29071 Málaga, Spain
| | - Francisco J. Ávila Ferrer
- Andalucía
Tech, Facultad de Ciencias, Departamento de Química Física, Universidad de Málaga, 29071 Málaga, Spain
| | - Fabrizio Santoro
- Istituto
di Chimica dei Composti Organometallici (ICCOM-CNR), Area della Ricerca
del CNR, Via Moruzzi 1, I-56124 Pisa, Italy
| | - Daniel Aranda
- Andalucía
Tech, Facultad de Ciencias, Departamento de Química Física, Universidad de Málaga, 29071 Málaga, Spain
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Shamsali F, Solovyeva EV, Nasiri N, Jamshidi Z. How is the Observation of High-Order Overtones and Combinations Elucidated by the Charge-Transfer Mechanism in SERS? J Phys Chem A 2023; 127:10583-10590. [PMID: 38079603 DOI: 10.1021/acs.jpca.3c05956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
The charge-transfer chemical mechanism is responsible for altering the molecular spectral pattern and providing valuable insights into the properties of adsorbates. The impact of charge transfer becomes more pronounced in SERS spectra when CT states can gain intensity through vibronic coupling with high-intensity excitations. Experimental SERS spectra of diamino molecules, such as 4,4'-diaminostilbene (DAS) and 4,4'-diaminotolane (DAT), featuring bright CT transitions, have been compared to dipyridyl compounds, such as 1,2-bis(4-pyridyl) ethylene (BPE) and 1,2-di(4-pyridyl) acetylene (DPA), characterized by nearly dark CT excitations. This comparison aims to elucidate the effect of CT transitions on the presence of overtones and combination bands. We explain this distinction using Albrecht's formalism for resonance Raman spectroscopy within the framework of path integral time-dependent density functional theory considering the Herzberg-Teller corrections. It is worth noting that the energy gap between the highest occupied metallic orbital and the lowest unoccupied molecular orbital in diamino derivatives is noticeably smaller than in compounds featuring two pyridyl rings. The high-intensity SERS-CT spectra for diamino derivatives, primarily driven by the Albrecht A term, were acquired and used to elucidate the experimental observation of high-order modes with a significant Huang-Rhys factor. Conversely, the absolute intensity of SERS-CT for dipyridyl compounds is at least 106 times smaller than that for diamines, and the C term makes a significant contribution, explaining the silent overtones.
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Affiliation(s)
- Fatemeh Shamsali
- Chemistry Department, Sharif University of Technology, 11155-9516 Tehran, Iran
| | - Elena V Solovyeva
- Chemistry Institute, Saint-Petersburg State University, 199034 Saint-Petersburg, Russian Federation
| | - Nima Nasiri
- Chemistry Department, Sharif University of Technology, 11155-9516 Tehran, Iran
| | - Zahra Jamshidi
- Chemistry Department, Sharif University of Technology, 11155-9516 Tehran, Iran
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Wang Q, Lian S, Guo C, Gao X, Dou Y, Song C, Lin J. The chemical adsorption effect of surface enhanced Raman spectroscopy of nitrobenzene and aniline using the density functional theory. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 279:121428. [PMID: 35660148 DOI: 10.1016/j.saa.2022.121428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 05/18/2022] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
Nitrobenzene and Aniline are representatives of the nitro or amino compounds of benzene, mainly used in the manufacture of dyes, spices, medicines, and so on. Extensive use of Nitrobenzene and Aniline may cause pesticide residue pollution and have carcinogenic effects on organisms. In this paper, the Nitrobenzene and Aniline single molecules and their complexes with gold nanoparticles are studied theoretically by Raman spectroscopy, the surface-enhanced Raman spectroscopy (SERS) and the density functional theory (DFT) simulations. Selective binding of gold nanoparticles (AuNPs) to the analyte was used to study the molecular electrostatic potential (MEP), frontier molecular orbital (FMO) and the Raman activity spectra of Nitrobenzene and Aniline, as well as the Raman activity spectrum of the complexes. The most electronegative sites of Nitrobenzene and Aniline are found in the MEP and the hypothesis that these sites might be the adsorption sites of Nitrobenzene/Aniline molecules at the gold surface. At the same time, the MEP of the Nitrobenzene/Aniline complexes also prove the existence of the charge transfer effect between Nitrobenzene/Aniline and Au. The FMO energy gap of Nitrobenzene/Aniline is 0.18983 eV and 0.18953 eV, respectively, and which, after adding the Au3 clusters, change to 0.03376 eV and 0.0797 eV, respectively, indicating that the Nitrobenzene/Aniline-Au3 complexes have stronger chemical activities and are more prone to the charge transfer effects. The electrophilic indices of Nitrobenzene (0.17921 eV) and Aniline (0.05635 eV) are calculated and analyzed, as well as that of Nitrobenzene/Aniline-Au3 complexes after adding the Au3 atomic clusters, 0.80819 eV and 0.19819 eV, respectively. The obvious increasing trend in the electrophilic indices of the Nitrobenzene/Aniline-Au3 complexes indicate their stronger biological activities and more prone to chemical reactions. The chemisorption of Nitrobenzene/Aniline and gold nanoparticles complexes is studied by the SERS, and the Raman formation of the complexes at different binding sites of Nitrobenzene/Aniline and Nitrobenzene/Aniline-Au3 is well explained by the surface selection rule. The reason for the selective enhancement of the spectral peaks presented in the Raman activity spectrum is calculated, and the enhancement factor of the chemical enhancement due to the charge transfer effect is calculated as well. The reason for the peak offset in the SERS spectrum to the conventional Raman spectrum is explained.
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Affiliation(s)
- Qi Wang
- School of Science, Changchun University of Science and Technology, Jilin, China
| | - Shuai Lian
- School of Science, Changchun University of Science and Technology, Jilin, China
| | - Chang Guo
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Jilin, China
| | - Xun Gao
- School of Science, Changchun University of Science and Technology, Jilin, China; Jilin Provincial Key Laboratory of Ultrafast and Extreme Ultraviolet Optics, Changchun, China.
| | - Yinping Dou
- School of Science, Changchun University of Science and Technology, Jilin, China; Jilin Provincial Key Laboratory of Ultrafast and Extreme Ultraviolet Optics, Changchun, China
| | - Chao Song
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Jilin, China.
| | - Jingquan Lin
- School of Science, Changchun University of Science and Technology, Jilin, China; Jilin Provincial Key Laboratory of Ultrafast and Extreme Ultraviolet Optics, Changchun, China
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Lian S, Gao X, Song C, Li H, Chen A, Lin J. The characteristics of Raman spectroscopy of isomer CBD- and THC-Au nanoparticles using the density functional theory. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 268:120682. [PMID: 34906842 DOI: 10.1016/j.saa.2021.120682] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 11/21/2021] [Accepted: 11/26/2021] [Indexed: 06/14/2023]
Abstract
The isomers cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) can both be extracted from cannabis. We use density functional theory to study the Raman activity spectra, frontier molecular orbitals, and molecular electrostatic potentials of CBD, THC, and their respective gold complexes. A "selectivity enhancement" phenomenon for the spectral peaks at frequencies of 1144 cm-1 and 1553 cm-1 in the Raman spectrum of the CBD-Aun complex, and at frequencies of 865 cm-1, 1335 cm-1, and 1553 cm-1 in the Raman spectrum of the THC-Aun complex, was observed and explained. The frontier molecular orbital energy gaps of CBD and THC are 5.4085 eV and 5.4461 eV, respectively, indicating that CBD is more likely to react than THC. The CBD/THC-Au complexes had the strongest chemical activities and greater charge transfer effects with an Au3 cluster. The most electronegative sites of CBD and THC were found from molecular electrostatic potential (MEP) mapping. It is assumed that these sites are the adsorption sites of the CBD/THC molecules and gold surface. The MEP of the CBD/THC complexes also demonstrates the charge transfer effect between CBD/THC and Au. Both the "selectivity" phenomenon in the Raman activity spectra of the complex and the above assumption are explained by a surface selection rule. The conformation of the CBD/THC molecules on the gold surface are determined, showing that CBD is adsorbed vertically through the resorcinol structure while THC is adsorbed vertically through the tetrahydropyran and benzene ring.
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Affiliation(s)
- Shuai Lian
- School of Science, Changchun University of Science and Technology, Chang Chun, China
| | - Xun Gao
- School of Science, Changchun University of Science and Technology, Chang Chun, China.
| | - Chao Song
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Chang Chun, China
| | - Hui Li
- School of Science, Changchun University of Science and Technology, Chang Chun, China
| | | | - Jingquan Lin
- School of Science, Changchun University of Science and Technology, Chang Chun, China
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Lian S, Gao X, Song C, Li H, Lin J. Chemical Enhancement Effect of Icotinib-Au Complex Studied by Combined Density Functional Theory and Surface-Enhanced Raman Scattering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:12907-12918. [PMID: 34705473 DOI: 10.1021/acs.langmuir.1c01957] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Icotinib is an epidermal growth factor receptor tyrosine kinase inhibitor used in the treatment of non-small cell lung cancer. The charge transfer effect between gold nanoparticles (AuNPs) and icotinib molecules can be used as a model to study the adsorption mechanism between molecules and metal. The adsorption of icotinib on the AuNP surface was confirmed by UV-vis and transmission electron microscopy (TEM) experiments. To explain the nature of chemisorption between icotinib and AuNPs from a theoretical perspective, the molecular correlation properties of the complex model of icotinib-Au6 were studied by the density functional theory method. By studying the molecular electrostatic potential of an icotinib molecule, four potential binding sites of the icotinib molecule were predicted. The calculation results of binding energy showed that the complex formed by chemisorption of icotinib through acetylene group and Au6 was the most stable one. The molecular frontier orbitals of icotinib and icotinib-Au6 confirmed that the charge transfer effect occurred on the acetylene group, benzene ring, and quinazoline ring of the icotinib molecule. The Herzberg-Teller surface selection rule was used to explain selective enhancement in the theoretically calculated Raman spectra. By comparing the spectra of theory and experiment, the cause of spectral peak shift and broadening that appeared in the surface-enhanced Raman scattering spectrum compared with the normal Raman spectrum was explained as well. This work would contribute to the development and application of the icotinib-Au drug carrier system.
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Affiliation(s)
- Shuai Lian
- School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022, China
| | - Xun Gao
- School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022, China
| | - Chao Song
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Changchun, Jilin 130022, China
| | - Hui Li
- School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022, China
| | - Jingquan Lin
- School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022, China
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Lian S, Gao X, Song C, Li H, Lin J. The characteristics of Raman spectroscopy of fenbendazole-gold nanoparticles based on the chemical adsorption effect. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 257:119799. [PMID: 33887509 DOI: 10.1016/j.saa.2021.119799] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 03/10/2021] [Accepted: 04/04/2021] [Indexed: 06/12/2023]
Abstract
Fenbendazole, a benzimidazole derivative with anti-tubulin polymerization properties, has been widely used in the treatment of parasitic infections. Because of its anticancer activity similar to that of many anticancer drugs, low cost and few side effects, fenbendazole has attracted wide research attention. The chemical adsorption of fenbendazole and gold nanoparticles are studied by the UV-Vis spectrophotometry, density functional method, Raman spectroscopy and surface-enhanced Raman spectroscopy. By comparing and analyzing the theoretical and experimental Raman spectra, this paper explains the reasons for the difference between the theoretical and experimental Raman spectra. Meanwhile, it is also found that the frequencies at 851 cm-1, 1222 cm-1, 1425 cm-1 and 1566 cm-1 are greatly enhanced. It is found that imidazole is adsorbed vertically to the surface of the substrate. It is concluded that Fenbendazole is vertically adsorbed on the surface of AuNPs through imidazole.
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Affiliation(s)
- Shuai Lian
- School of Science, Changchun University of Science and Technology, Jilin, China
| | - Xun Gao
- School of Science, Changchun University of Science and Technology, Jilin, China.
| | - Chao Song
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Jilin, China.
| | - Hui Li
- School of Science, Changchun University of Science and Technology, Jilin, China
| | - Jingquan Lin
- School of Science, Changchun University of Science and Technology, Jilin, China
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