JGU-Forschungsdaten

Permanent URI for this collectionhttps://openscience.ub.uni-mainz.de/handle/20.500.12030/6735

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  • ItemDatensammlungOpen 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, René
    Indolizines 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.
  • ItemDatensammlungOpen Access
    Quantitativer Datensatz zum Projekt BRIDGE
    (2024) Zlatkin-Troitschanskaia, Olga
    Datensatz 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)
  • ItemDatensammlungOpen Access
    Datensatz Umfrage "KI und gute wissenschaftliche Praxis"
    (2024) Baravalle, Martina; Reineke, Esther; Rotzal, Tina; Schuh, Dominik; Straßl, Karl-Gerhard
    KI-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).
  • ItemDatensammlungOpen 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, Christoph
    Norbornadiene-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.
  • ItemDatensammlungOpen Access
    Reaching the voters : parties use of Google Ads in the 2021 German federal election
    (2024) Fitzpatrick, Jasmin; Nostitz, Felix-Christopher von
    Based 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)
  • ItemDatensammlungOpen 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, Christoph
    Photocatalysis 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.
  • ItemDatensammlungOpen 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, Christoph
    Organic 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.
  • ItemDatensammlungOpen Access
    Quantitativer Datensatz zum Projekt MP-INVET
    (2023) Zlatkin-Troitschanskaia, Olga
    Datensatz 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.
  • ItemDatensammlungOpen Access
    Raw data for "Coulomb interactions for mediator-enhanced sensitized triplet-triplet annihilation upconversion in solution"
    (2023) Glaser, Felix; Schmitz, Matthias; Kerzig, Christoph
    Sensitized 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.
  • ItemDatensammlungOpen 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, Christoph
    Alkenylboronates 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.
  • ItemFilmOpen 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, Monika
    This 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.
  • ItemDatensammlungOpen Access
    Datensatz zum Projekt WiWiKom II
    (2023) Zlatkin-Troitschanskaia, Olga; Pant, Hans Anand
    Datensatz (.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/10.1080/02602938.2022.2040001
  • ItemDatensammlungOpen Access
    Datensatz zum Projekt WiWiSET
    (2023) Zlatkin-Troitschanskaia, Olga; Pant, Hans Anand
    Datensatz (.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/10.1080/02602938.2022.2040001
  • ItemAnderer ForschungsdatentypOpen Access
    Testverfahren TEL IV G [Test of Economic Literacy 4. Version German]
    (2023) Zlatkin-Troitschanskaia, Olga
    Adaption (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.
  • ItemAnderer ForschungsdatentypOpen Access
    WiWiKom II Testverfahren
    (2023) Zlatkin-Troitschanskaia, Olga; Pant, Hans Anand
    Testverfahren 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.
  • ItemAnderer ForschungsdatentypOpen Access
    WiWiSET Testverfahren
    (2023) Zlatkin-Troitschanskaia, Olga; Pant, Hans Anand
    Testverfahren 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.
  • ItemDatensammlungOpen Access
    Raw data for "Triplet quenching pathway control with molecular dyads enables the identification of a highly oxidizing annihilator class"
    (2023) Bertrams, Maria-Sophie; Hermainski, Katharina; Mörsdorf, Jean-Marc; Ballmann, Joachim; Kerzig, Christoph
    Metal complex – arene dyads typically act as more potent triplet energy donors compared to their parent metal complexes, which is frequently exploited for increasing the efficiencies of energy transfer applications. Using unexplored dicationic phosphonium-bridged ladder stilbenes (P-X^2+) as quenchers, we exclusively observed photoinduced electron transfer photochemistry with commercial organic photosensitizers and photoactive metal complexes. In contrast, corresponding pyrene dyads of the tested ruthenium complexes with the very same metal complex units efficiently sensitize the P-X^2+ triplets. The long-lived and comparatively redox-inert pyrene donor triplet in the dyads thus provides an efficient access to acceptor triplet states that are otherwise very tricky to obtain. This dyad-enabled control over the quenching pathway allowed us to explore the P-X^2+ photochemistry in detail using laser flash photolysis. The P-X^2+ triplet undergoes annihilation producing the corresponding excited singlet, which is an extremely strong oxidant (+2.3 V vs. NHE) as demonstrated by halide quenching experiments. This behavior was observed for three P^2+ derivatives allowing us to add a novel basic structure to the very limited number of annihilators for sensitized triplet-triplet annihilation in neat water.
  • ItemDatensammlungOpen Access
    Confetti model simulation data
    (2022) Klenke, Achim
    We simulate confetti of radius 0.05 at random positions in the plane. The numbers are the number of confetti centered in the unit square that are visible. The sample size is 5000000
  • ItemDatensammlungOpen Access
    Raw data for "Blue-to-UVB upconversion, solvent sensitization and challenging bond activation enabled by a benzene-based annihilator"
    (2022) Zähringer, Till J. B.; Moghtader, Julian A.; Bertrams, Maria-Sophie; Roy, Bibhisan; Uji, Masanori; Yanai, Nobuhiro; Kerzig, Christoph
    Several energy-demanding photoreactions require harsh UV light from inefficient light sources. The conversion of low-energy visible light to high-energy singlet states via triplet-triplet annihilation upconversion (TTA-UC) could offer a solution for driving such reactions under mild conditions. We present the first annihilator with an emission maximum in the UVB region that, combined with an organic sensitizer, is suitable for blue-to-UV upconversion. The annihilator singlet was successfully employed as an energy donor in subsequent FRET activations of aliphatic carbonyls. This hitherto unreported UC-FRET reaction sequence was directly monitored using laser spectroscopy and applied to mechanistic irradiation experiments demonstrating the feasibility of Norrish chemistry. Our results provide clear evidence for a novel blue light-driven substrate or solvent activation strategy, which is important in the context of developing more sustainable light-to-chemical energy conversion systems.
  • ItemFilmOpen Access
    Sounding Out DAESH
    (2022) Dick, Alexandra; Günther, Christoph; Pfeifer, Simone; Hartmann, Eva; Evans, Jenny; Alkatreeb, Majd
    Sound production has been crucial to the self-presentation strategy of the so-called Islamic State that we refer to in our video by its Arabic acronym DAESH. A cappella chants (anāshīd) often sonically enhance DAESH’s highly polished videos and have been widely disseminated on social media platforms. Anāshīd reach out to a wide audience in a variety of languages, but rarely gain the attention their popularity requires. DAESH’s videos and statements mark their singers as heroic figures, showing them with rifles, the black flag, and microphones. However, it remains difficult to see beyond this imposing staging to learn more about the composition and production of the crafted sounds and the individual men and, to some extent, women behind them. This academic video essay draws attention to the often-neglected dimension of sound among DAESH. It probes what is known about the singers and the production process of anāshīd and presents new perspectives on the potential of DAESH’s media campaign to touch through sound and poetry.