Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall Inks
FT-Raman, FTIR, and SERS spectra of the structurally related gallnut polyphenols tannic acid, gallic acid, pyrogallol, and syringic acid are reported in this work aiming at performing a comparative assignation of the bands and finding specific marker features that can identify these compounds in com...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-01-01
|
| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/27/1/279 |
| _version_ | 1797498220773900288 |
|---|---|
| author | Alba Espina Santiago Sanchez-Cortes Zuzana Jurašeková |
| author_facet | Alba Espina Santiago Sanchez-Cortes Zuzana Jurašeková |
| author_sort | Alba Espina |
| collection | DOAJ |
| description | FT-Raman, FTIR, and SERS spectra of the structurally related gallnut polyphenols tannic acid, gallic acid, pyrogallol, and syringic acid are reported in this work aiming at performing a comparative assignation of the bands and finding specific marker features that can identify these compounds in complex polyphenol mixtures. Tannic and gallic acids are the principal components in oak gallnuts, and they can be found in iron gall inks. The different functional groups existing in these molecules and their spatial distribution lead to slight changes of the vibrations. The Raman spectra are dominated by bands corresponding to the ring vibrations, but the substituents in the ring strongly affect these vibrations. In contrast, the FTIR spectra of these molecules are dominated by the peripheral oxygen-containing substituents of the aromatic ring and afford complementary information. SERS spectroscopy can be used to analyze trace amounts of these compounds, but the spectra of these polyphenols show strong changes in comparison with the Raman spectra, indicating a strong interaction with the metal. The most significant modification observed in the SERS spectra of these compounds is the weakening of the benzene <i>8a</i> ring vibration and the subsequent intensification of the <i>19a</i> mode of the benzene ring. This mode is also more intense in the FTIR spectra, and its intensification in the SERS spectra could be related to a drastic change in the molecular polarizability associated with the interaction of the polyphenol with the metal in Ag NPs. |
| first_indexed | 2024-03-10T03:30:19Z |
| format | Article |
| id | doaj.art-d8dff01d8e814075bfcd46fc90fbdd97 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T03:30:19Z |
| publishDate | 2022-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-d8dff01d8e814075bfcd46fc90fbdd972023-11-23T11:59:20ZengMDPI AGMolecules1420-30492022-01-0127127910.3390/molecules27010279Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall InksAlba Espina0Santiago Sanchez-Cortes1Zuzana Jurašeková2Department of Biophysics, Faculty of Science, Pavol Jozef Safarik University, 040 01 Kosice, SlovakiaInstituto de Estructura de la Materia (CSIC), Serrano, 121, 280 06 Madrid, SpainDepartment of Biophysics, Faculty of Science, Pavol Jozef Safarik University, 040 01 Kosice, SlovakiaFT-Raman, FTIR, and SERS spectra of the structurally related gallnut polyphenols tannic acid, gallic acid, pyrogallol, and syringic acid are reported in this work aiming at performing a comparative assignation of the bands and finding specific marker features that can identify these compounds in complex polyphenol mixtures. Tannic and gallic acids are the principal components in oak gallnuts, and they can be found in iron gall inks. The different functional groups existing in these molecules and their spatial distribution lead to slight changes of the vibrations. The Raman spectra are dominated by bands corresponding to the ring vibrations, but the substituents in the ring strongly affect these vibrations. In contrast, the FTIR spectra of these molecules are dominated by the peripheral oxygen-containing substituents of the aromatic ring and afford complementary information. SERS spectroscopy can be used to analyze trace amounts of these compounds, but the spectra of these polyphenols show strong changes in comparison with the Raman spectra, indicating a strong interaction with the metal. The most significant modification observed in the SERS spectra of these compounds is the weakening of the benzene <i>8a</i> ring vibration and the subsequent intensification of the <i>19a</i> mode of the benzene ring. This mode is also more intense in the FTIR spectra, and its intensification in the SERS spectra could be related to a drastic change in the molecular polarizability associated with the interaction of the polyphenol with the metal in Ag NPs.https://www.mdpi.com/1420-3049/27/1/279polyphenolsgallnutiron gall inksRamanFTIRSERS |
| spellingShingle | Alba Espina Santiago Sanchez-Cortes Zuzana Jurašeková Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall Inks Molecules polyphenols gallnut iron gall inks Raman FTIR SERS |
| title | Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall Inks |
| title_full | Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall Inks |
| title_fullStr | Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall Inks |
| title_full_unstemmed | Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall Inks |
| title_short | Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall Inks |
| title_sort | vibrational study raman sers and ir of plant gallnut polyphenols related to the fabrication of iron gall inks |
| topic | polyphenols gallnut iron gall inks Raman FTIR SERS |
| url | https://www.mdpi.com/1420-3049/27/1/279 |
| work_keys_str_mv | AT albaespina vibrationalstudyramansersandirofplantgallnutpolyphenolsrelatedtothefabricationofirongallinks AT santiagosanchezcortes vibrationalstudyramansersandirofplantgallnutpolyphenolsrelatedtothefabricationofirongallinks AT zuzanajurasekova vibrationalstudyramansersandirofplantgallnutpolyphenolsrelatedtothefabricationofirongallinks |