Applying Two-Dimensional Correlation Spectroscopy and Principal Component Analysis to Understand How Temperature Affects the Neptunium(V) Absorption Spectrum
The visible-near infrared (Vis-NIR) electronic absorption spectrum of neptunium(V) (NpO<sub>2</sub><sup>+</sup>) comprises numerous <i>f-f</i> electronic transitions with mostly undocumented temperature dependencies. The effect of temperature on the absorption spe...
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MDPI AG
2022-11-01
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| Series: | Chemosensors |
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| Online Access: | https://www.mdpi.com/2227-9040/10/11/475 |
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| author | Luke R. Sadergaski Kyle Morgan |
| author_facet | Luke R. Sadergaski Kyle Morgan |
| author_sort | Luke R. Sadergaski |
| collection | DOAJ |
| description | The visible-near infrared (Vis-NIR) electronic absorption spectrum of neptunium(V) (NpO<sub>2</sub><sup>+</sup>) comprises numerous <i>f-f</i> electronic transitions with mostly undocumented temperature dependencies. The effect of temperature on the absorption spectrum of the pentavalent neptunyl dioxocation (NpO<sub>2</sub><sup>+</sup>) is an important factor to consider with spectrophotometric applications but has often been overlooked. Optical Vis-NIR absorption spectra (400–1700 nm) of Np(V) (0.017–0.89 M) in 1 M nitric acid were evaluated with varying temperatures (T = 10–80 °C). The intensity, position, and overall shape of the bands were sensitive to interactions with the solvent and coordination environment. Numerous temperature-induced isosbestic points were identified resulting from dynamic, overlapping peak shifts. Spectral variations were characterized using principal component analysis (PCA) and 2D correlation spectroscopy (COS). 2D-COS revealed that the absorption band near 1095 nm likely consists of two bands centered near 1087 and 1096 nm, which cannot be explained by current computational methods. 2D-COS analysis also provided an unambiguous assignment of unresolved peaks in the visible region for comparison with computational predictions. PCA was used to identify nonlinearity in the spectral response at elevated Np(V) concentrations ≥ 0.5 M. This unique experimental data and interpretation will foster a deeper understanding of the absorption spectra for complex actinyl ions. |
| first_indexed | 2024-03-09T18:24:05Z |
| format | Article |
| id | doaj.art-0722434c6bf14e16a1bf13a2aa71a178 |
| institution | Directory Open Access Journal |
| issn | 2227-9040 |
| language | English |
| last_indexed | 2024-03-09T18:24:05Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
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| series | Chemosensors |
| spelling | doaj.art-0722434c6bf14e16a1bf13a2aa71a1782023-11-24T07:59:46ZengMDPI AGChemosensors2227-90402022-11-01101147510.3390/chemosensors10110475Applying Two-Dimensional Correlation Spectroscopy and Principal Component Analysis to Understand How Temperature Affects the Neptunium(V) Absorption SpectrumLuke R. Sadergaski0Kyle Morgan1Radioisotope Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USADepartment of Chemistry, University of Florida, Gainesville, FL 32611, USAThe visible-near infrared (Vis-NIR) electronic absorption spectrum of neptunium(V) (NpO<sub>2</sub><sup>+</sup>) comprises numerous <i>f-f</i> electronic transitions with mostly undocumented temperature dependencies. The effect of temperature on the absorption spectrum of the pentavalent neptunyl dioxocation (NpO<sub>2</sub><sup>+</sup>) is an important factor to consider with spectrophotometric applications but has often been overlooked. Optical Vis-NIR absorption spectra (400–1700 nm) of Np(V) (0.017–0.89 M) in 1 M nitric acid were evaluated with varying temperatures (T = 10–80 °C). The intensity, position, and overall shape of the bands were sensitive to interactions with the solvent and coordination environment. Numerous temperature-induced isosbestic points were identified resulting from dynamic, overlapping peak shifts. Spectral variations were characterized using principal component analysis (PCA) and 2D correlation spectroscopy (COS). 2D-COS revealed that the absorption band near 1095 nm likely consists of two bands centered near 1087 and 1096 nm, which cannot be explained by current computational methods. 2D-COS analysis also provided an unambiguous assignment of unresolved peaks in the visible region for comparison with computational predictions. PCA was used to identify nonlinearity in the spectral response at elevated Np(V) concentrations ≥ 0.5 M. This unique experimental data and interpretation will foster a deeper understanding of the absorption spectra for complex actinyl ions.https://www.mdpi.com/2227-9040/10/11/475multivariate analysisabsorptionnitric acidspectrophotometryactinide |
| spellingShingle | Luke R. Sadergaski Kyle Morgan Applying Two-Dimensional Correlation Spectroscopy and Principal Component Analysis to Understand How Temperature Affects the Neptunium(V) Absorption Spectrum Chemosensors multivariate analysis absorption nitric acid spectrophotometry actinide |
| title | Applying Two-Dimensional Correlation Spectroscopy and Principal Component Analysis to Understand How Temperature Affects the Neptunium(V) Absorption Spectrum |
| title_full | Applying Two-Dimensional Correlation Spectroscopy and Principal Component Analysis to Understand How Temperature Affects the Neptunium(V) Absorption Spectrum |
| title_fullStr | Applying Two-Dimensional Correlation Spectroscopy and Principal Component Analysis to Understand How Temperature Affects the Neptunium(V) Absorption Spectrum |
| title_full_unstemmed | Applying Two-Dimensional Correlation Spectroscopy and Principal Component Analysis to Understand How Temperature Affects the Neptunium(V) Absorption Spectrum |
| title_short | Applying Two-Dimensional Correlation Spectroscopy and Principal Component Analysis to Understand How Temperature Affects the Neptunium(V) Absorption Spectrum |
| title_sort | applying two dimensional correlation spectroscopy and principal component analysis to understand how temperature affects the neptunium v absorption spectrum |
| topic | multivariate analysis absorption nitric acid spectrophotometry actinide |
| url | https://www.mdpi.com/2227-9040/10/11/475 |
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