Two-photon absorption and excitation spectroscopy of carotenoids, chlorophylls and pigment–protein complexes
| العنوان: | Two-photon absorption and excitation spectroscopy of carotenoids, chlorophylls and pigment–protein complexes |
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| المؤلفون: | Heiko Lokstein, Alexander Betke, Daniel A. Gacek, Peter Walla, Julia Nowak |
| المصدر: | Physical Chemistry Chemical Physics. 23:8731-8738 |
| بيانات النشر: | Royal Society of Chemistry (RSC), 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | Chlorophyll, Physics, Photons, Spectrum Analysis, Light-Harvesting Protein Complexes, General Physics and Astronomy, Photochemistry, Photosystem I, Carotenoids, Two-photon absorption, Spectral line, Wavelength, Excited state, Molecule, Physical and Theoretical Chemistry, Absorption (electromagnetic radiation), Excitation |
| الوصف: | In addition to (bacterio)chlorophylls, (B)Chls, photosynthetic pigment-protein complexes bind carotenoids (Cars) that fulfil various important functions which are not fully understood, yet. However, certain excited states of Cars are optically one-photon forbidden ("dark") and can potentially undergo excitation energy transfer (EET) to (B)Chls following two-photon absorption (TPA). The amount of EET is reflected by the differences in TPA and two-photon excitation (TPE) spectra of a complex (multi-pigment) system. Since it is technically and analytically demanding to resolve optically forbidden states, different studies reported varying contributions of Cars and Chls to TPE/TPA spectra. In a study using well-defined 1 : 1 Car-tetrapyrrole dyads TPE contributions of tetrapyrrole molecules, including Chls, and Cars were measured. In these experiments, TPE of Cars dominated over Chl a TPE in a broad wavelength range. Another study suggested only minor contributions of Cars to TPE spectra of pigment-protein complexes such as the plant main light-harvesting complex (LHCII), in particular for wavelengths longer than ∼600/1200 nm. By joining forces and a combined analysis of all available data by both teams, we try to resolve this apparent contradiction. Here, we demonstrate that reconstruction of a wide spectral range of TPE for LHCII and photosystem I (PSI) requires both, significant Car and Chl contributions. Direct comparison of TPE spectra obtained in both studies demonstrates a good agreement of the primary data. We conclude that in TPE spectra of LHCII and PSI, the contribution of Chls is dominating above 600/1200 nm, whereas the contributions of forbidden Car states increase particularly at wavelengths shorter than 600/1200 nm. Estimates of Car contributions to TPA as well as TPE spectra are given for various wavelengths. |
| تدمد: | 1463-9084 1463-9076 |
| DOI: | 10.1039/d1cp00656h |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6f1ce93e5a8a2e75df66e1e3eb757930 https://doi.org/10.1039/d1cp00656h |
| Rights: | CLOSED |
| رقم الانضمام: | edsair.doi.dedup.....6f1ce93e5a8a2e75df66e1e3eb757930 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14639084 14639076 |
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| DOI: | 10.1039/d1cp00656h |