Article
Biochemistry & Molecular Biology
Susanna Ciuti, Alessandro Agostini, Antonio Barbon, Marco Bortolus, Harald Paulsen, Marilena Di Valentin, Donatella Carbonera
Summary: This study investigates the photoexcited triplet state of chlorophyll a in different environments using magnetophotoselection (MPS) technique. The relative orientation of the optical transition dipole moment and the zero-field splitting tensor axes are determined through the combination of photoselection and magnetic selection. This methodology proves to be robust and quantitative in describing the excitonic interactions among pigments.
Article
Biochemistry & Molecular Biology
Donatella Carbonera, Alessandro Agostini, Marco Bortolus, Luca Dall'Osto, Roberto Bassi
Summary: This study investigates the effects of different carotenoids replacing lutein on the quenching behavior in LHCII. The results show that efficient TTET can be maintained regardless of the identity of the carotenoid accommodated.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Biochemistry & Molecular Biology
Alessandro Agostini, Lauren Nicol, Nicola Da Roit, Marco Bortolus, Roberta Croce, Donatella Carbonera
Summary: The triplet states in the monomeric light-harvesting complex II (LHCII) were analyzed using EPR and ODMR methods, revealing the energy transfer mechanisms between Chl a612/Lut620 and Chl a603/Lut621 pairs in LHCII. The study confirmed the robust photoprotective mechanism of LHCII and its ability to adapt to the removal of individual chromophores.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2021)
Article
Chemistry, Multidisciplinary
Arianna Actis, Michele Melchionna, Giacomo Filippini, Paolo Fornasiero, Maurizio Prato, Mario Chiesa, Enrico Salvadori
Summary: Time-resolved EPR technique was used to study the formation of well-defined spin triplet excitons in carbon nitride. The mobility of the triplet excitons was revealed through the analysis of temperature-dependent TR-EPR signal. It was found that the energy of the spin triplet is approximately 0.2 eV higher than the conduction band edge, suggesting the inversion of singlet-triplet in carbon nitride materials. This study provides important insights into the response of carbon nitride to light and the nature of photoexcited states.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Multidisciplinary Sciences
Ryan D. D. Dill, Kori E. E. Smyser, Brandon K. K. Rugg, Niels H. H. Damrauer, Joel D. D. Eaves
Summary: Singlet fission is important for next-generation solar cells. The authors design a molecular system with specific spin sub-levels that can produce highly entangled states. They demonstrate that the coherence between magnetic sub-levels of that state can be preserved at higher temperatures than conventional superconducting quantum hardware.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Ryhor Fedaruk, Roman Strzelczyk, Grigory A. Rusetsky, Antonio Barbon, Lukasz Majchrzycki, Maria A. Augustyniak-Jablokow
Summary: Glass-like carbons (GLCs) are disordered carbon materials with high concentration of paramagnetic centers (PCs). The origin and identification of these PCs have remained unknown due to the complex electron paramagnetic resonance (EPR) spectrum caused by high electrical conductivity. In this study, vacuum Rabi splitting and Rabi oscillations were used to investigate GLC produced by pyrolysis of phenol-formaldehyde resin. The results revealed the spin concentration, the temperature dependence of EPR susceptibility, and the presence of excited triplet states.
Review
Chemistry, Inorganic & Nuclear
Rafael Calvo, Rosana P. Sartoris, Otaciro R. Nascimento, Matus Sedivy, Antonin Sojka, Petr Neugebauer, Vinicius T. Santana
Summary: In this work, recent advances in the interpretation of EPR spectral changes in dimeric spin arrays with weak inter-dimeric couplings are collected. Experimental results are explained by proposing a spin model with a microscopic flip-flop mechanism involving the absorption and emission of two simultaneous spin-one excitations. The model considers the role of energy conservation in the process and allows for analysis and simulation of the EPR spectra features.
COORDINATION CHEMISTRY REVIEWS
(2023)
Article
Biochemistry & Molecular Biology
Alessandro Agostini, David Bina, Donatella Carbonera, Radek Litvin
Summary: Detailed information on photo-generated triplet states of diatom and haptophyte Fucoxanthin Chlorophyll-binding Proteins (FCPs and E-FCPs) has been obtained through a combined spectroscopic investigation. The study reveals a shared photoprotective triplet-triplet energy transfer pathway in these proteins involving a specific Fucoxanthin site.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2023)
Article
Chemistry, Physical
George A. Sutherland, James P. Pidgeon, Harrison Ka Hin Lee, Matthew S. Proctor, Andrew Hitchcock, Shuangqing Wang, Dimitri Chekulaev, Wing Chung Tsoi, Matthew P. Johnson, C. Neil Hunter, Jenny Clark
Summary: Singlet exciton fission is the process of generating two triplet excited states from a singlet state. Previous studies suggested that intramolecular singlet fission occurs only in protein complexes with twisted carotenoid molecules. In this research, we studied a one-carotenoid system, the orange carotenoid protein (OCP), and found no evidence of intramolecular singlet fission despite the twist in the carotenoid molecule.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Plant Sciences
Jens Niklas, Alessandro Agostini, Donatella Carbonera, Marilena Di Valentin, Wolfgang Lubitz
Summary: The photoexcited triplet state of the primary donors in the two photosystems of oxygenic photosynthesis has been investigated using the electron-nuclear double resonance (ENDOR) technique. The results confirm that the primary donor triplet is located on a specific chlorophyll molecule in both photosystems at cryogenic temperature. This research provides important insights into the mechanism of photosynthesis.
PHOTOSYNTHESIS RESEARCH
(2022)
Article
Microbiology
Patsharaporn T. Sarasombath, Jerapas Thongpiya, Monrat Chulanetra, Sirirat Wijit, Pisith Chinabut, Jeerawan Ongrotchanakun, Anupop Jitmuang, Darawan Wanachiwanawin
Summary: This study aimed to differentiate between PCP and Pneumocystis jirovecii colonization using qPCR to determine DNA copies in respiratory specimens of HIV and non-HIV patients. The study identified upper and lower cut-off values for PCP diagnosis in both groups, which showed high sensitivity and specificity in distinguishing PCP patients.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Chemistry, Physical
Joshua K. G. Karlsson, Alparslan Atahan, Anthony Harriman, Nikolai Tkachenko, Andrew D. Ward, Fabio A. Schaberle, Carlos Serpa, Luis G. Arnaut
Summary: A covalently linked bichromophore with TIPS-pentacene terminals bridged by a rigid fluorene spacer can generate a relatively high yield of spin-correlated triplet biexciton upon illumination in toluene. Fluorescence quenching relative to the parent TIPS-pentacene approaches 97% and is temperature insensitive. Processes of spin decorrelation and evolution of independent triplet pair occur on different time scales and can be analyzed through photoacoustic calorimetry.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Chemistry, Physical
Lucas M. Uriarte, Raffaele Vitale, Stanislaw Nizinski, Kyprianos Hadjidemetriou, Ninon Zala, Andras Lukacs, Gregory M. Greetham, Igor Sazanovich, Martin Weik, Cyril Ruckebusch, Stephen R. Meech, Michel Sliwa
Summary: This study investigates the structural characteristics of RsEGFP2 using femto- to millisecond time-resolved multiple-probe infrared spectroscopy (TRMPS-IR). The results reveal the presence of a subpicosecond twisted excited state precursor during the trans-to-cis isomerization process, and the chromophore takes approximately 100 ps to reach its final position within the protein pocket.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Xiaosong Cao, Ke Pan, Jingsheng Miao, Xialei Lv, Zhongyan Huang, Fan Ni, Xiaojun Yin, Yaxiong Wei, Chuluo Yang
Summary: In this study, a MR-TADF compound (BN-Se) with efficient spin-flip transition, fast radiative decay, close-to-unity quantum yield, and narrowband emission was reported. The compound showed excellent performance in OLEDs and as a photosensitizer, highlighting its potential beyond OLED applications.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Olga B. Morozova, Alexandra V. Yurkovskaya
Summary: This study investigated the reduction of carnosine radicals in neutral and basic aqueous solutions by l-tryptophan, N-acetyl tryptophan, and the Trp-Gly peptide using time-resolved chemically induced dynamic nuclear polarization (TR CIDNP). The reduction reaction rate constants were found to be influenced by the protonation state of the non-reacting β-alanine residue of carnosine radicals. Clear differences were observed compared to the reduction of histidine and N-acetyl histidine radicals, as well as the reduction of radicals derived from Gly-His, a homologue of carnosine.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Physics, Atomic, Molecular & Chemical
Susanna Ciuti, Antonio Barbon, Marco Bortolus, Alessandro Agostini, Elisabetta Bergantino, Caterina Martin, Marilena Di Valentin, Donatella Carbonera
Summary: The study investigated the photo-excited triplet state of Zn-protoporphyrin IX in the heme pocket of human neuroglobin using time-resolved EPR coupled to magnetophotoselection. The results show that the protein matrix stabilizes the coordination of the embedded chromophore, leading to a more homogeneous environment compared to a glassy solvent. Furthermore, the EPR-magnetophotoselection technique allowed for a reinterpretation of the assignment of the Q bands in the electronic absorption spectrum.
APPLIED MAGNETIC RESONANCE
(2022)
Article
Biochemistry & Molecular Biology
Francesco Tumbarello, Giampaolo Marcolin, Elisa Fresch, Eckhard Hofmann, Donatella Carbonera, Elisabetta Collini
Summary: This study investigated the energy transfer from carotenoids to chlorophylls in marine algae using two-dimensional electronic spectroscopy. Relevant details on the mechanism of excitation transfer were unveiled by comparing mutant and normal systems.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Biochemistry & Molecular Biology
Alessandro Agostini, David Bina, Donatella Carbonera, Radek Litvin
Summary: Detailed information on photo-generated triplet states of diatom and haptophyte Fucoxanthin Chlorophyll-binding Proteins (FCPs and E-FCPs) has been obtained through a combined spectroscopic investigation. The study reveals a shared photoprotective triplet-triplet energy transfer pathway in these proteins involving a specific Fucoxanthin site.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2023)
Article
Chemistry, Physical
Yu-Kai Liao, Valeria Lagostina, Enrico Salvadori, Martin Hartmann, Andreas Poeppl, Mario Chiesa
Summary: Engineering two cooperative sites in a catalyst can lead to synergistic effects due to short-range electronic interactions between two metal components. However, obtaining these interactions and structure-property correlations is often challenging. In this study, hyperfine spectroscopy was used to detect V4+-O-Mo6+ linkages and assess spin density transfer between paramagnetic V4+ species and proximal oxo-bridged Mo6+ metal ions. The research demonstrated the presence of well-defined bimetallic V-O-Mo structures by preparing dimer species through adsorption, thermal decomposition, oxidation, grafting, hydrolysis, and dehydration processes. X- and Q-band EPR and HYSCORE experiments provided direct evidence of spin delocalization over Al-27, P-31, Mo-95, and Mo-97 nuclei.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Plant Sciences
Stefano Santabarbara, Alessandro Agostini, Anastasia A. A. Petrova, Marco Bortolus, Anna Paola Casazza, Donatella Carbonera
Summary: Photo-induced triplet states in the thylakoid membranes of Acaryocholoris marina, a cyanobacterium with Chl d as its main chromophore, were investigated using ODMR and TR-EPR. Four Chl d triplet populations were detected under ambient redox conditions, and-T3 became dominant after illumination with TMPD and ascorbate. Another triplet population -T4 was also observed with an intensity ratio of 1:4 compared to -T3. TR-EPR experiments indicated that these triplets were formed by intersystem crossing and bleached the P-740 singlet state in the PSI reaction center.
PHOTOSYNTHESIS RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Fabio Santanni, Matteo Briganti, Giulia Serrano, Enrico Salvadori, Alessandro Veneri, Chiara Batistoni, Sofia F. Russi, Stefano Menichetti, Matteo Mannini, Mario Chiesa, Lorenzo Sorace, Roberta Sessoli
Summary: Sulfur-rich molecular complexes of dithiolene-like ligands are promising candidates for molecular spin qubits due to enhanced spin coherence properties in hydrogen-free environments. In this study, the mononegative 1,3,2-dithiazole-4-thione-5-thiolate (dttt-) ligand was used as an alternative to common dinegative dithiolate ligands. The synthesis and structural characterization of Cu2+, Ni2+, and Pt2+ complexes with this ligand were reported for the first time. XPS analysis indicated that intact molecules can be deposited on surfaces by sublimation, and AF exchange interactions mediated by S center dot center dot center dot S VdW interactions were observed.
Article
Nanoscience & Nanotechnology
P. Ragonese, B. Kalinic, L. Franco, L. Girardi, B. M. Fernandez Perez, D. Carbonera, G. Mattei, G. -A. Rizzi, C. Maurizio
Summary: This study focuses on Co3O4/SiOx/Si and NiO/SiOx/Si photoanodes and reveals that defects in the native SiOx layer significantly affect the onset of photocurrent. Vacuum annealing can eliminate some defects and improve the photovoltage and charge transfer efficiency.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Davide Ranieri, Alberto Privitera, Fabio Santanni, Karolina Urbanska, Grant J. Strachan, Brendan Twamley, Enrico Salvadori, Yu-Kai Liao, Mario Chiesa, Mathias O. Senge, Federico Totti, Lorenzo Sorace, Roberta Sessoli
Summary: By synthesizing and studying a VIVO-CuII porphyrin dimer, we observed measurable exchange coupling and good spin coherence, making it suitable for operating two-qubit molecular spin-based quantum gates under various conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Arianna Actis, Michele Melchionna, Giacomo Filippini, Paolo Fornasiero, Maurizio Prato, Mario Chiesa, Enrico Salvadori
Summary: Time-resolved EPR technique was used to study the formation of well-defined spin triplet excitons in carbon nitride. The mobility of the triplet excitons was revealed through the analysis of temperature-dependent TR-EPR signal. It was found that the energy of the spin triplet is approximately 0.2 eV higher than the conduction band edge, suggesting the inversion of singlet-triplet in carbon nitride materials. This study provides important insights into the response of carbon nitride to light and the nature of photoexcited states.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemistry & Molecular Biology
Alessandro Agostini, Gaozhong Shen, Donald A. Bryant, John H. Golbeck, Art van der Est, Donatella Carbonera
Summary: This study reveals the differences in photochemistry between ChlF and PSII in cyanobacteria undergoing far red light photoacclimation (FaRLiP). Specifically, the triplet state of P680 formed by intersystem crossing is the primary species generated by light excitation in untreated ChlF samples, whereas in PSII, 3P680 is only formed when the quinone acceptors are removed or chemically reduced. Additionally, the study shows the involvement of carotenoid and a small amount of Chl f in the photochemistry process.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2023)
Article
Biochemical Research Methods
Angelo Carella, Susanna Ciuti, Haakon T. A. Wiedemann, Christopher W. M. Kay, Arthur van der Est, Donatella Carbonera, Antonio Barbon, Prashanth K. Poddutoori, Marilena Di Valentin
Summary: In this study, the photoexcited triplet state of octaethylaluminum(III)-porphyrin (AlOEP) was investigated using various techniques. The results show that the magnetic resonance properties of AlOEP are influenced by the presence of a dynamic process, resulting in temperature-dependent zero-field splitting parameters and hyperfine coupling tensor components. These findings contribute to a better understanding of AlOEP and its potential applications.
JOURNAL OF MAGNETIC RESONANCE
(2023)
Article
Chemistry, Multidisciplinary
Arnau Bertran, Laura Morbiato, Jack Sawyer, Chiara Dalla Torre, Derren J. Heyes, Sam Hay, Christiane R. Timmel, Marilena Di Valentin, Marta De Zotti, Alice M. Bowen
Summary: In this study, dual triplet-spin/fluorescent labels are used to perform parallel distance measurements by electron spin resonance (ESR) and Förster resonance energy transfer (FRET) on the same molecules with orthogonal chromophores, allowing for direct comparison. An improved light-induced triplet-triplet electron resonance method with 2-color excitation is employed, leading to a higher signal-to-noise ratio and yielding a more insightful distance distribution compared to FRET.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Miriam Marchi, Edoardo Raciti, Sai Manoj Gali, Federica Piccirilli, Hendrik Vondracek, Arianna Actis, Enrico Salvadori, Cristian Rosso, Alejandro Criado, Carmine D'Agostino, Luke Forster, Daniel Lee, Alexandre C. Foucher, Rajeev Kumar Rai, David Beljonne, Eric A. Stach, Mario Chiesa, Roberto Lazzaroni, Giacomo Filippini, Maurizio Prato, Michele Melchionna, Paolo Fornasiero
Summary: The manipulation of carbon nitride (CN) structures through microwave treatment enhances the activity of CN-based photocatalysts for Ni dual photocatalysis. This approach improves the efficiency of C-X (X = N, S, O) couplings in organic synthesis reactions. The formation of carbon vacancies and subsequent evolution into triazole and imine N species play a crucial role in the enhanced reactivity of the material.
Article
Chemistry, Inorganic & Nuclear
Manuel Imperato, Alessio Nicolini, Marco Borsari, Matteo Briganti, Mario Chiesa, Yu-Kai Liao, Antonio Ranieri, Arsen Raza, Enrico Salvadori, Lorenzo Sorace, Andrea Cornia
Summary: We investigated the performance of heterobimetallic lantern complexes [PtVO(SOCR)4] as charge neutral electronic qubits based on vanadyl complexes. The results showed that these complexes exhibit good spin coherence properties, making them suitable for applications in materials science and quantum technologies.
INORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Physical
Agostino Migliore, Stefano Corni, Alessandro Agostini, Donatella Carbonera
Summary: The influence of carotenoid triplet states on the Q(y) electronic transitions of chlorophylls has been explained through a comparative study of chlorophyll-carotenoid model dyads and larger pigment complexes. The results suggest that singlet-like triplet excitations on chlorophylls influenced by a stable electronic triplet on the carotenoid determine the spectral feature in the triplet minus singlet (T-S) absorption spectra of photosystems.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Biochemistry & Molecular Biology
Brandon P. Russell, David J. Vinyard
Summary: The Mn4CaO5 oxygen-evolving complex in Photosystem II is crucial for water oxidation. D1 residue R334 participates in proton release and interacts with PsbO. A D1-R334G mutant destabilizes the OEC but stabilizes the S2 intermediate.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2024)
Article
Biochemistry & Molecular Biology
Alexander A. Bulychev, Tatiana S. Strelets
Summary: Excitable cells of higher plants and characean algae respond to stressful stimuli by generating action potentials that influence chlorophyll fluorescence and photosynthesis for an extended period of time. While plant leaves exhibit a reversible depression in the efficiency of photosystem II reaction after an individual action potential, characean algae show long-lasting oscillations of photosystem II reaction efficiency after firing an action potential. This study investigates the possible mechanisms behind these oscillations and suggests that they are a result of metabolic rearrangements in chloroplasts and the cyclosis cessation-recovery cycle induced by calcium influx during action potentials. The findings also indicate that fluidic communications between different cell regions play a role in these oscillations, and the inhibition of oscillations occurs when these communications are restricted or eliminated.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2024)
Article
Biochemistry & Molecular Biology
Dmitry Zlenko, Elena A. Protasova, Georgy Tsoraev, Nikolai N. Sluchanko, Dmitry A. Cherepanov, Thomas Friedrich, Baosheng Ge, Song Qin, Eugene G. Maksimov, Andrew B. Rubin
Summary: The conformation of chromophores in isolated phycobiliproteins is heterogeneous, but not in the entire phycobilisome (PBS). Under low-energy excitation, there is no significant uphill energy transfer from the core to the peripheral rods of the PBS, while transfer from the terminal emitters to bulk allophycocyanin chromophores is highly probable.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2024)
Article
Biochemistry & Molecular Biology
Makio Yokono, Chiyo Noda, Jun Minagawa
Summary: This paper investigates the energy transfer between Photosystem II and Photosystem I in Arabidopsis thaliana, and finds that the fast spillover is reversibly regulated depending on pH.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2024)
