JGU-Forschungsdaten
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Item Datensammlung Open Access Raw data for "Efficient red light-driven singlet oxygen photocatalysis with an osmium-based Coulombic dyad"(2025) Schmitz, Matthias; Naumann, Robert; Heinze, Katja; Kerzig, ChristophPhotoactive osmium complexes are widely used sensitizers for the generation of singlet oxygen, because they can be excited directly into their triplet states with low-energy red light. However, their short-lived excited states reduce quenching efficiencies and reaction quantum yields significantly. To elongate the excited state lifetime, osmium complexes have been linked to organic chromophores to form molecular dyads. This approach, while effective, is time- and resource-consuming, hampering larger-scale applications. Here, we demonstrate a straightforward approach by directly mixing a readily available cationic osmium complex and an anionic perylene derivative in solution. Strong Coulombic interactions facilitate rapid energy transfer (~100 ps) from the excited osmium complex to the perylene derivative, mimicking a dyad-like system. Detailed spectroscopic investigations revealed an increased singlet oxygen formation rate by over one order of magnitude at sub-millimolar perylene concentrations, attributed to (i) the three orders of magnitude longer lifetime of the perylene triplet state produced via intra-ion-pair energy transfer and (ii) an inherently high singlet oxygen quantum yield of that key species. The novel catalyst system enables highly productive photooxygenations in water and in a MeOH/H2O 10/1 mixture, highlighting the broad applicability and versatility of the Coulombic dyad approach for photocatalytic synthesis and wastewater treatment.Item Datensammlung Open Access Raw data for "Mechanistic insights: correspondence on “Tuning co-operative energy transfer in copper(I) complexes using two-photon absorbing diimine-based ligand sensitizers”"(2025) Moghtader, Julian A.; Bertrams, Maria-Sophie; Schollmeyer, Dieter; Kerzig, ChristophIn a recent communication, Collins and co-workers presented a Cu(I) complex with photocatalytic activity under red light LED conditions, mainly for singlet oxygen-driven reactions. Guided by steady-state emission measurements with 800 nm excitation, the authors suggested that the underlying mechanism for the generation of the photoexcited key species is a simultaneous two-photon absorption via a virtual state. However, such a mechanism requires pulsed laser excitation and cannot compete when a conventional one-photon excitation is also feasible with the selected excitation wavelength range. Using several spectroscopic techniques and reactivity assays under different light color and intensity conditions, we unambiguously demonstrate that a conventional one-photon excitation followed by rather inefficient singlet oxygen generation (quantum yield < 5%) is responsible for the observed photoreactivity of the Cu(I) complex. In addition, we briefly summarize general mechanistic considerations, estimate typical photon densities required for a variety of two-photon mechanisms, highlight the importance of optical filters and impurities to avoid artifacts in the emission spectra, and present some guidelines for the differentiation between one- and two-photon mechanisms.Item Datensammlung Open Access Raw data for "Direct observation of triplet-triplet energy transfer in DNA between energy donor and acceptor C-nucleotides"(2025) Häcker, Sebastian; Zähringer, Till J. B.; Wagenknecht, Hans-Achim; Kerzig, ChristophInvestigating the migration of excited-state energy in DNA is crucial for a deep understanding of protection mechanisms and light-induced DNA damage. While numerous reports focused on single electron transfer and Förster-type energy transfer in DNA, studies on the Dexter-type triplet-triplet energy transfer are scarce, in particular those with direct detection of photoexcited triplet states. Herein, we present direct measurements of the distance-dependent triplet-triplet energy transfer rates through DNA by using transient absorption spectroscopy. This was achieved through the synthetic incorporation of thioxanthone as an energy donor and naphthalene as an energy acceptor into a DNA double strand at defined positions. The energy transfer rates strongly depend on the number of A-T base pairs (up to four) separating the energy donor from the energy acceptor. We observed a fast energy transfer rate with a time constant of 17 ns for the DNA sample in which the donor and acceptor are directly adjacent in the DNA. By analyzing two additional donor-acceptor distances, a steep exponential distance dependence with an attenuation factor of 1.15 Å^-1 could be obtained. Our results demonstrate that DNA acts as a poor conductor of triplet energy when energy donors with triplet energies below 2.7 eV are used, complementing more indirect studies on sensitized DNA damage.Item Datensammlung Open Access Raw data for "Pushing the limit of triplet-triplet annihilation photon upconversion towards the UVC range"(2025) Zähringer, Till J. B.; Heusel, Corinna; Schmitz, Matthias; Glorius, Frank; Kerzig, ChristophTriplet-triplet annihilation photon upconversion (TTA-UC) provides a milder alternative to traditional UVB/UVC photochemistry. However, suitable sensitizer-annihilator pairs are scarce, in particular in the high-energy UV regime. Herein, we present a benzene-based annihilator that, paired with a suitable sensitizer, generates upconverted emission approaching the UVC region for the first time.Item Datensammlung Open Access Raw data for "Bichromophoric ruthenium complexes for photocatalyzed late-stage synthesis of trifluoromethylated indolizines"(2025) Stefanoni, Kevin; Schmitz, Matthias; Treuheit, Johanna; Kerzig, Christoph; Wilhelm, RenéIndolizines are a promising class of biologically active compounds. However, photocatalytic methods for their selective derivatization are scarce in the literature. Herein, a mild, simple and chemoselective protocol for the synthesis of 3-(trifluoromethyl)indolizine has been developed. The desired products were obtained in good to excellent yields and can be easily obtained on gram scale. By tuning the redox properties of a Ru-based photocatalyst it is possible to achieve competitive yields and further apply the optimized conditions to a broad variety of substrates. This method tolerates many functional groups and therefore can be used for late-stage functionalization. Our combined theoretical and spectroscopic findings revealed that the superior dyad-like ruthenium catalyst developed in this study has a completely different electronic nature of both key species that are crucial for efficient photoredox catalysis compared to commonly used homoleptic ruthenium complexes.Item Datensammlung Open Access Quantitativer Datensatz zum Projekt BRIDGE(2024) Zlatkin-Troitschanskaia, OlgaDatensatz Online-Fragebogen (Gen-Cor, t1 und t2), Logdaten und Ratings (.xlsx [Excel]) zum BMBF-geförderten Projekt BRIDGE: Berufspraktische Bildungsprozesse im Recht- und Lehramtsreferendariat sowie der Medizin unter Nutzung digitaler Medien (Verbundprojektleitung: Univ.-Prof. Dr. Olga Zlatkin-Troitschanskaia (JGU Mainz)). Bei Interesse an einer Nutzung des Datensatzes wenden Sie sich bitte an den Lehrstuhl Wirtschaftspädagogik)Item Datensammlung Open Access Datensatz Umfrage "KI und gute wissenschaftliche Praxis"(2024) Baravalle, Martina; Reineke, Esther; Rotzal, Tina; Schuh, Dominik; Straßl, Karl-GerhardKI-Systeme sind zunehmend Teil unseres Alltags und spielen auch in Schreibprozessen an Hochschulen/Universitäten eine wachsende Rolle. Aktuell steht dabei im Mittelpunkt, wie textgenerierende KI-Systeme das Schreiben an Hochschulen/Universitäten beeinflussen – besonders im Hinblick auf Fragen guter wissenschaftlicher Praxis (gwP). Die Umfrage richtete sich an zentrale Akteur:innen im gwP-Bereich um zu eruieren, inwieweit normierende oder didaktisch-konstruktive Perspektiven und Aktivitäten zum Einsatz textgenerativer KI verbreitet sind. Die Datei zeigt die nicht bereinigten Rohdaten der Umfrage. Daraus resultierende Ergebnisse werden in folgender Publikation vorgestellt: Baravalle, M., Reineke, E., Rotzal, T., Schuh, D., Straßl. K. (2024): "KI und gute wissenschaftliche Praxis (GWP) - Perspektiven von GWP-Trainer:innen". Arbeitspapier Nr. 84. Berlin: Hochschulforum Digitalisierung (CC-BY-SA 4.0).Item Datensammlung Open Access Raw data for "Triplet-sensitized switching of high-energy-density norbornadienes for molecular solar thermal energy storage with visible Light"(2024) Zähringer, Till J. B.; Perez Lopez, Nico; Schulte, Robin; Schmitz, Matthias; Ihmels, Heiko; Kerzig, ChristophNorbornadiene-based photoswitches have emerged as promising candidates for harnessing and storing solar energy, holding great promise as a viable solution to meet the growing energy demands. Despite their potential, the effectiveness of their direct photochemical conversion into the resulting quadricyclanes has room for improvement owing to (i) moderate quantum yields, (ii) poor overlap with the solar spectrum and (iii) photochemical back reactions. Herein, we present an approach to enhance the performance of such molecular solar thermal energy storage (MOST) systems through the triplet-sensitized conversion of aryl-substituted norbornadienes. Our study combines deep spectroscopic analyses, irradiation experiments, and quantum mechanical calculations to elucidate the energy transfer mechanism and inherent advantages of the resulting MOST systems. We demonstrate remarkable quantum yields using readily available sensitizers under both LED and solar light irradiation, significantly surpassing those achieved through direct excitation with photons of higher energy. In contrast to the conventional approach, light-induced back reactions of the high-energy products do not play any role, allowing quantitative switching within minutes. These results not only underscore the potential of triplet-sensitized MOST systems to leverage the high energy storage capabilities of multistate photoswitches but they might also stimulate the broader usage of sensitization strategies in photochemical energy conversion.Item Datensammlung Open Access Raw data for "Reaching the voters : parties use of Google Ads in the 2021 German federal election"(2024) Fitzpatrick, Jasmin; Nostitz, Felix-Christopher vonBased on the public data provided via Google's Ads Library, we constructed a subset consisting of political ads displayed during the final eight weeks leading up to the 2021 Bundestag election (the main campaign period). The subset contains 5131 observations, from 27 July to 26 September 2021, focusing only on ads from political parties and their chapters. We grouped the advertisers by party (15 in total) and created a variable indicating the organizational level (federal, state, local, or youth organizations). The data was processed using RStudio 2024.04.2 (R version 4.4.1)Item Datensammlung Open Access Raw data for "Efficient energy and electron transfer photocatalysis with a Coulombic dyad"(2024) Schmitz, Matthias; Bertrams, Maria-Sophie; Sell, Arne C.; Glaser, Felix; Kerzig, ChristophPhotocatalysis holds great promise for changing the way value-added molecules are currently prepared. However, many photocatalytic reactions suffer from quantum yields well below 10 %, hampering the transition from lab-scale reactions to large-scale or even industrial applications. Molecular dyads can be designed such that the beneficial properties of inorganic and organic chromophores are combined, resulting in milder reaction conditions and improved quantum yields of photocatalytic reactions. We have developed a novel approach for obtaining the advantages of molecular dyads without the time- and resource-consuming synthesis of these tailored photocatalysts. Simply by mixing a cationic ruthenium complex with an anionic pyrene derivative in water a salt bichromophore is produced owing to electrostatic interactions. The long-lived organic triplet state is obtained by static and quantitative energy transfer from the preorganized ruthenium complex. We exploited this so-called Coulombic dyad for energy transfer catalysis with similar reactivity and even higher photostability compared to a molecular dyad and reference photosensitizers in several photooxygenations. In addition, it was shown that this system can also be used to maximize the quantum yield of photoredox reactions. This is due to an intrinsically higher cage escape quantum yield after photoinduced electron transfer for purely organic compounds compared to heavy atom-containing molecules. The combination of laboratory-scale as well as mechanistic irradiation experiments with detailed spectroscopic investigations provided deep mechanistic insights into this easy-to-use photocatalyst class.Item Datensammlung Open Access Raw data for "Mechanistic investigations of polyaza[7]helicene in photoredox and energy transfer catalysis"(2024) Rocker, Johannes; Zähringer, Till J. B.; Schmitz, Matthias; Opatz, Till; Kerzig, ChristophOrganic photocatalysts frequently possess dual singlet and triplet photoreactivity and a thorough photochemical characterization is essential for efficient light-driven applications. In this article, the mode of action of a polyazahelicene catalyst (Aza-H) was investigated using laser flash photolysis (LFP). The study revealed that the chromophore can function as a singlet-state photoredox catalyst in the sulfonylation/arylation of styrenes and as a triplet sensitizer in energy transfer catalysis. The singlet lifetime is sufficiently long to exploit the exceptional excited state reduction potential for the activation of 4-cyanopyridine. Photoinduced electron transfer generating the radical cation was directly observed confirming the previously proposed mechanism of a three-component reaction. Several steps of the photoredox cycle were investigated separately, providing deep insights into the complex mechanism. The triplet-excited Aza-H, which was studied with quantitative LFP, is formed with a quantum yield of 0.34. The pronounced triplet formation was exploited for the isomerization reaction of (E)-stilbene to the Z-isomer and the cyclization of cinnamyl chloride. Catalyst degradation mainly occurs through the long-lived Aza-H triplet (28 µs), but the photostability is greatly increased when the triplet efficiently reacts in a catalytic cycle such that turnover numbers exceeding 4400 are achievable with this organocatalyst.Item Datensammlung Open Access Quantitativer Datensatz zum Projekt MP-INVET(2023) Zlatkin-Troitschanskaia, OlgaDatensatz Online-Fragebogen (t1 und t2) (.xlsx [Excel]) zum BMBF-geförderten Projekt MP-INVET: Metaprojekt zur Forschung zur Internationalisierung der Berufsbildung (Verbundprojektleitung: Univ.-Prof. Dr. Olga Zlatkin-Troitschanskaia (JGU Mainz)). Bei Interesse an einer Nutzung des Datensatzes wenden Sie sich bitte an den Lehrstuhl Wirtschaftspädagogik.Item Datensammlung Open Access Raw data for "Coulomb interactions for mediator-enhanced sensitized triplet-triplet annihilation upconversion in solution"(2023) Glaser, Felix; Schmitz, Matthias; Kerzig, ChristophSensitized triplet-triplet annihilation upconversion offers an attractive possibility to replace a high-energy photon by two photons with lower energy through the combination of a light-harvesting triplet sensitizer and an annihilator for the formation of a fluorescent singlet state. Typically, high annihilator concentrations are required to achieve an efficient initial energy transfer and as a direct consequence the most highly energetic emission is often not detectable due to intrinsic reabsorption by the annihilator itself. Herein, we demonstrate that the addition of a charge-adapted mediator drastically improves the energy transfer efficiency at low annihilator concentrations via an energy transfer cascade. Inspired by molecular dyads and recent developments in nanocrystal-sensitized upconversion, our system exploits a concept to minimize intrinsic filter effects, while boosting the upconversion quantum yield in solution. A sensitizer-annihilator combination consisting of a ruthenium-based complex and 9,10-diphenylanthracene (DPA) is explored as model system and a sulfonated pyrene serves as mediator. The impact of opposite charges between sensitizer and mediator – to induce Coulombic attraction and subsequently result in accelerated energy transfer rate constants – is analyzed in detail by different spectroscopic methods. Ion pairing and the resulting static energy transfer in both directions is a minor process, resulting in an improved overall performance. Finally, the more intense upconverted emission in the presence of the mediator is used to drive two catalytic photoreactions in a two-chamber setup, illustrating the advantages of our approach, in particular for photoreactions requiring oxygen that would interfere with the upconversion system.Item Datensammlung Open Access Raw data for "Direct observation of triplet states in the isomerization of alkenylboronates by energy transfer catalysis"(2023) Zähringer, Till J. B.; Wienhold, Max; Gilmour, Ryan; Kerzig, ChristophAlkenylboronates are versatile building blocks for stereocontrolled synthesis owing to the traceless nature of the boron group that can be leveraged to achieve highly selective geometric isomerization. Using thioxanthone as an inexpensive photocatalyst, their photoisomerization continues to provide an expansive platform for stereodivergent synthesis, particularly in the construction of bioactive polyenes. Although mechanistic investigations are consistent with light−driven energy transfer, direct experimental evidence remains conspicuously absent. Herein, we report a rigorous mechanistic investigation using two widely used alkenylboronates alongside relevant reference compounds. Through the combination of irradiation experiments, transient absorption spectroscopic studies, kinetic modeling, and DFT calculations with all isomers of the model compounds, it has been possible to unequivocally detect and characterize the perpendicular triplet generated by energy transfer. Our results serve not only as a blueprint for mechanistic studies that are challenging with organic sensitizers, but these guidelines delineated have also enabled the development of more sustainable reaction conditions: for the first time, efficient organocatalytic isomerization under sunlight irradiation has become feasible.Item Film Open Access 'The Lady of All' – Reading the Queen in the Life of Sinuhe(2023) Parkinson, Richard Bruce; Gerhards, Simone; Gräßler, Nadine; Gülden, Svenja A.; Ilin-Tomich, Alexander; Kertmann, Jessica; Konrad, Tobias; Kreis-Thies, Ruth; Kilian, Andrea; Moezel, Kyra van der; Zöller-Engelhardt, MonikaThis lecture is a recording of the celebratory lecture on the occasion of the retirement of Univ.-Prof. Dr. Ursula Verhoeven-van Elsbergen, long-time professor of Egyptology at the Johannes Gutenberg University Mainz, in March 2023. Prof. Richard Bruce Parkinson from the University of Oxford presents research results in honor of his colleague and friend.Item Datensammlung Open Access Datensatz zum Projekt WiWiKom II(2023) Zlatkin-Troitschanskaia, Olga; Pant, Hans AnandDatensatz (.dta [Stata]) zum BMBF-geförderten Projekt Projekt WiWiSET (Zlatkin-Troitschanskaia et al., 2022). Bei Interesse an einer Nutzung des Datensatzes wenden Sie sich bitte an den Lehrstuhl Wirtschaftspädagogik (Prof. Zlatkin-Troitschanskaia) der JGU Mainz. Zlatkin-Troitschanskaia, O., Kühling-Thees, C., Gordon, J., Reichert-Schlax, J., Happ, R., & Pant, H. A. (2022). Improving study admission through entry diagnostics using a validated subject-specific test. Assessment & Evaluation in Higher Education, 1–15. https://doi.org/10.1080/02602938.2022.2040001Item Datensammlung Open Access Datensatz zum Projekt WiWiSET(2023) Zlatkin-Troitschanskaia, Olga; Pant, Hans AnandDatensatz (.dta [Stata]) zum BMBF-geförderten Projekt Projekt WiWiSET (Zlatkin-Troitschanskaia et al., 2022). Bei Interesse an einer Nutzung des Datensatzes wenden Sie sich bitte an den Lehrstuhl Wirtschaftspädagogik (Prof. Zlatkin-Troitschanskaia) der JGU Mainz. Zlatkin-Troitschanskaia, O., Kühling-Thees, C., Gordon, J., Reichert-Schlax, J., Happ, R., & Pant, H. A. (2022). Improving study admission through entry diagnostics using a validated subject-specific test. Assessment & Evaluation in Higher Education, 1–15. https://doi.org/10.1080/02602938.2022.2040001Item Anderer Forschungsdatentyp Open Access Testverfahren TEL IV G [Test of Economic Literacy 4. Version German](2023) Zlatkin-Troitschanskaia, OlgaAdaption (Happ et al., 2016) des TEL IV (Walstad et al., 2013), Vollversion mit Testvarianten A & B (je 45 Items). Bei Interesse an einer Nutzung des Verfahrens zu Forschungszwecken wenden Sie sich bitte an den Lehrstuhl Wirtschaftspädagogik (Prof. Zlatkin-Troitschanskaia) der JGU Mainz. Happ, R., Förster, M., Zlatkin-Troitschanskaia, O., & Carstensen, V. (2016). Assessing the previous economic knowledge of beginning students in Germany: Implications for teaching economics in basic courses. Citizenship, Social and Economics Education, 15(1), 45–57. https://doi.org/10.1177/2047173416646597 Walstad, W. B., Rebeck, K., & Butters, R. B. (2013). Test of Economic Literacy: Examiner’s Manual (4th ed.). Council for Economic Education.Item Anderer Forschungsdatentyp Open Access WiWiKom II Testverfahren(2023) Zlatkin-Troitschanskaia, Olga; Pant, Hans AnandTestverfahren im BMBF geförderten WiWiKom II Projekt (Zlatkin-Troitschanskaia et al., 2019), Kurztest über 25 Items, adaptierte Testitems aus TEL IV und TUCE IV (Walstad et al., 2007, 2013). Bei Interesse an einer Nutzung des Verfahrens zu Forschungszwecken wenden Sie sich bitte an den Lehrstuhl Wirtschaftspädagogik (Prof. Zlatkin-Troitschanskaia) der JGU Mainz. Zlatkin-Troitschanskaia, O., Jitomirski, J., Happ, R., Molerov, D., Schlax, J., Kühling-Thees, C., Förster, M., & Brückner, S. (2019). Validating a Test for Measuring Knowledge and Understanding of Economics Among University Students. Zeitschrift Für Pädagogische Psychologie, 33(2), 119–133. https://doi.org/10.1024/1010-0652/a000239 Walstad, W. B., Rebeck, K., & Butters, R. B. (2013). Test of Economic Literacy: Examiner’s Manual (4th ed.). Council for Economic Education. Walstad, W. B., Watts, M., & Rebeck, K. (2007). The Test of Understanding in College Economics: Examiner`s manual (4th ed.). National Council on Economic Education.Item Anderer Forschungsdatentyp Open Access WiWiSET Testverfahren(2023) Zlatkin-Troitschanskaia, Olga; Pant, Hans AnandTestverfahren zum BMBF-geförderten Projekt Projekt WiWiSET (Zlatkin-Troitschanskaia et al., 2022), Adaption des TEL IV (Walstad et al., 2013), Kurztest aus 15 Items. Bei Interesse an einer Nutzung des Verfahrens zu Forschungszwecken wenden Sie sich bitte an den Lehrstuhl Wirtschaftspädagogik (Prof. Zlatkin-Troitschanskaia) der JGU Mainz. Zlatkin-Troitschanskaia, O., Kühling-Thees, C., Gordon, J., Reichert-Schlax, J., Happ, R., & Pant, H. A. (2022). Improving study admission through entry diagnostics using a validated subject-specific test. Assessment & Evaluation in Higher Education, 1–15. https://doi.org/10.1080/02602938.2022.2040001 Walstad, W. B., Rebeck, K., & Butters, R. B. (2013). Test of Economic Literacy: Examiner’s Manual (4th ed.). Council for Economic Education.