@phdthesis{Wehner2021, author = {Wehner, Marius}, title = {Supramolecular Polymorphism in Homo- and Heterochiral Supramolecular Polymerizations}, doi = {10.25972/OPUS-21151}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211519}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {The aim of the first part of this thesis was to investigate (R,R)-PBI as a model system for polymorphism at its origin by a supramolecular approach. The pathway complexity of (R,R)-PBI was fine-tuned by experimental parameters such as solvent, temperature and concentration to make several supramolecular polymorphs accessible. Mechanistic and quantum chemical studies on the kinetics and thermodynamics of the supramolecular polymerization of (R,R)-PBI were conducted to shed light on the initial stages of polymorphism. The second part of this work deals with mechanistic investigations on the supramolecular polymerization of the racemic mixture of (R,R)- and (S,S)-PBI with regard to homochiral and heterochiral aggregation leading to conglomerates and a racemic supramolecular polymer, respectively.}, subject = {Supramolekulare Chemie}, language = {en} } @article{WehnerRoehrStepanenkoetal.2020, author = {Wehner, Marius and R{\"o}hr, Merle Insa Silja and Stepanenko, Vladimir and W{\"u}rthner, Frank}, title = {Control of self-assembly pathways toward conglomerate and racemic supramolecular polymers}, series = {Nature Communications}, volume = {11}, journal = {Nature Communications}, doi = {10.1038/s41467-020-19189-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230580}, year = {2020}, abstract = {Homo- and heterochiral aggregation during crystallization of organic molecules has significance both for fundamental questions related to the origin of life as well as for the separation of homochiral compounds from their racemates in industrial processes. Herein, we analyse these phenomena at the lowest level of hierarchy - that is the self-assembly of a racemic mixture of (R,R)- and (S,S)-PBI into 1D supramolecular polymers. By a combination of UV/vis and NMR spectroscopy as well as atomic force microscopy, we demonstrate that homochiral aggregation of the racemic mixture leads to the formation of two types of supramolecular conglomerates under kinetic control, while under thermodynamic control heterochiral aggregation is preferred, affording a racemic supramolecular polymer. FT-IR spectroscopy and quantum-chemical calculations reveal unique packing arrangements and hydrogen-bonding patterns within these supramolecular polymers. Time-, concentration- and temperature-dependent UV/vis experiments provide further insights into the kinetic and thermodynamic control of the conglomerate and racemic supramolecular polymer formation. Homo- and heterochiral aggregation is a process of interest to prebiotic and chiral separation chemistry. Here, the authors analyze the self-assembly of a racemic mixture into 1D supramolecular polymers and find homochiral aggregation into conglomerates under kinetic control, while under thermodynamic control a racemic polymer is formed.}, language = {en} } @article{FarmerStrzelczykFinisguerraetal.2021, author = {Farmer, Adam D. and Strzelczyk, Adam and Finisguerra, Alessandra and Gourine, Alexander V. and Gharabaghi, Alireza and Hasan, Alkomiet and Burger, Andreas M. and Jaramillo, Andr{\´e}s M. and Mertens, Ann and Majid, Arshad and Verkuil, Bart and Badran, Bashar W. and Ventura-Bort, Carlos and Gaul, Charly and Beste, Christian and Warren, Christopher M. and Quintana, Daniel S. and H{\"a}mmerer, Dorothea and Freri, Elena and Frangos, Eleni and Tobaldini, Eleonora and Kaniusas, Eugenijus and Rosenow, Felix and Capone, Fioravante and Panetsos, Fivos and Ackland, Gareth L. and Kaithwas, Gaurav and O'Leary, Georgia H. and Genheimer, Hannah and Jacobs, Heidi I. L. and Van Diest, Ilse and Schoenen, Jean and Redgrave, Jessica and Fang, Jiliang and Deuchars, Jim and Sz{\´e}les, Jozsef C. and Thayer, Julian F. and More, Kaushik and Vonck, Kristl and Steenbergen, Laura and Vianna, Lauro C. and McTeague, Lisa M. and Ludwig, Mareike and Veldhuizen, Maria G. and De Couck, Marijke and Casazza, Marina and Keute, Marius and Bikson, Marom and Andreatta, Marta and D'Agostini, Martina and Weymar, Mathias and Betts, Matthew and Prigge, Matthias and Kaess, Michael and Roden, Michael and Thai, Michelle and Schuster, Nathaniel M. and Montano, Nicola and Hansen, Niels and Kroemer, Nils B. and Rong, Peijing and Fischer, Rico and Howland, Robert H. and Sclocco, Roberta and Sellaro, Roberta and Garcia, Ronald G. and Bauer, Sebastian and Gancheva, Sofiya and Stavrakis, Stavros and Kampusch, Stefan and Deuchars, Susan A. and Wehner, Sven and Laborde, Sylvain and Usichenko, Taras and Polak, Thomas and Zaehle, Tino and Borges, Uirassu and Teckentrup, Vanessa and Jandackova, Vera K. and Napadow, Vitaly and Koenig, Julian}, title = {International Consensus Based Review and Recommendations for Minimum Reporting Standards in Research on Transcutaneous Vagus Nerve Stimulation (Version 2020)}, series = {Frontiers in Human Neuroscience}, volume = {14}, journal = {Frontiers in Human Neuroscience}, issn = {1662-5161}, doi = {10.3389/fnhum.2020.568051}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234346}, year = {2021}, abstract = {Given its non-invasive nature, there is increasing interest in the use of transcutaneous vagus nerve stimulation (tVNS) across basic, translational and clinical research. Contemporaneously, tVNS can be achieved by stimulating either the auricular branch or the cervical bundle of the vagus nerve, referred to as transcutaneous auricular vagus nerve stimulation(VNS) and transcutaneous cervical VNS, respectively. In order to advance the field in a systematic manner, studies using these technologies need to adequately report sufficient methodological detail to enable comparison of results between studies, replication of studies, as well as enhancing study participant safety. We systematically reviewed the existing tVNS literature to evaluate current reporting practices. Based on this review, and consensus among participating authors, we propose a set of minimal reporting items to guide future tVNS studies. The suggested items address specific technical aspects of the device and stimulation parameters. We also cover general recommendations including inclusion and exclusion criteria for participants, outcome parameters and the detailed reporting of side effects. Furthermore, we review strategies used to identify the optimal stimulation parameters for a given research setting and summarize ongoing developments in animal research with potential implications for the application of tVNS in humans. Finally, we discuss the potential of tVNS in future research as well as the associated challenges across several disciplines in research and clinical practice.}, language = {en} }