GDCh Kolloquium Professor Dr. Carsten Reinhardt
16.05.2023 von 17:00 bis 18:00

Chemistry in the 20th Century: Materials, Methods, Residues During the 20th century, chemistry expanded through its methods into many neighboring scientific fields. At the same time, the enormous growth of chemical production, coupled with globalization, led to an increasingly troublesome chemical pollution and severe environmental problems. In my talk, I will present historiographical methods in order to tackle these developments. Bonn JCF will host a reception following the lecture. Come meet other chemists over drinks and snacks!

GDCh Kolloquium - Professor Dr. Olivier Mentré
06.06.2023 von 17:00 bis 18:00

What layered iron compounds can offer, and more ... I will introduce recently-found 2D inorganic compounds based on layers of Fe2+ (S=2) ions, in order to highlight how they form a unique platform for new paradigms on spin-dynamics and magneto-dielectric couplings. Here, depending on the crystal structure, the spin-degrees of freedoms and fine anionic compositions are the key-ingredients to tune the exchanges, crystal field ... etc. Especially, I will show in a specific 2D-Ising-ferromagnet (BaFe2(PO4)2) the occurrence of giant magneto-crystalline anisotropy. It results in the collective freezing of magnetic domains which mediates the passage from a soft to a ‘super-hard’ magnet. This unique situation offers various unexpected peculiarities including the ability to imprint any unreturnable magnetization to the sample within simple temperature/field cycles.

GDCh Kolloquium - Professor Dr. Jieping Zhu
20.06.2023 von 17:00 bis 18:00

Catalytic Enantioselective Pictet-Spengler Reaction of Ketones: Development and Applications in the Total Synthesis of Indole Alkaloids The asymmetric Pictect-Spengler reaction (PSR) between tryptamine and aldehydes is now well-developed. Conversely, catalytic enantioselective PSR of ketone is essentially unexploited. In this presentation, we will present our work on the catalytic enantioselective PSR of tryptamine with 1,2-diones, α-ketoesters and α-ketoamide for the synthesis of enantioenriched 1,1-Disubstituted tetrahydro-β-carboline (THBC) and their application in the total synthesis of monoterpene indole alkaloids.

GDCh Kolloquium - Junge Forscher stellen sich vor
04.07.2023 von 16:00 bis 21:00

Stefan Flesch Photolytical formation of a nitrido-iron(V) complex tracked by ultrafast mid-IR spectroscopy Hagen Neugebauer Toward reliable quantum chemical modeling of homogeneous 3d transition metal electrocatalysis Lea Schmidt Mixed-metal monophosphate tungsten bronzes containing divalent transition metal ions (M<sup>2</sup>: Fe, Co, Ni) and tungsten(VI) Houchao Xu The Mysterious Case of Sodorifen Biosynthesis Anschliessend BBQ

GDCh Kolloquium - Professor Dr. Thomas Ebbesen
23.05.2023 von 17:00 bis 18:00

Hybridizing Light and Matter – Consequences for Chemical and Material Sciences Over the past decade, the possibility of manipulating material and chemical properties by using hybrid light-matter states has stimulated considerable interest. Such hybrid light-matter states can be generated by strongly coupling the electronic or the vibrational transitions of a material, to the spatially confined electromagnetic field of an optical resonator. Most importantly, this occurs even in the dark because the coupling involves the zero-point electromagnetic fluctuations of the resonator, the vacuum field. After introducing the fundamental concepts, examples of modified properties of strongly coupled systems, such as chemical reactivity, charge and energy transport, and magnetism will be given to illustrate the broad potential of light-matter states.

GDCh-Kolloquium - Professor Dr. Patrick Holland
22.03.2023 von 17:00 bis 18:00

Breaking it and fixing it: new chemistry with nitrogen Atmospheric N<sub>2</sub> is a cheap, abundant resource with great potential for energy storage and chemical escribe the challenges and opportunities of nitrogen fixation, as well as my students' disynthesis, but it is difficult to convert it into other compounds ("fixing" nitrogen). This seminar will dscoveries of how to break the N–N bond of N<sub>2</sub> using homogeneous transition-metal complexes. In addition to new catalysts for producing ammonia, we have identified a new mechanism for sequential C-H activation and N-N activation to create C-N bonds. Detailed mechanistic studies reveal a cyclic reaction, which gives a route from atmospheric N<sub>2</sub> and petroleum-derived arenes to substituted anilines. This is an important step toward preparing useful chemicals using air as a starting material.

GDCh-Kolloquium - Dr. Dr. h.c. Peter Gölitz
17.01.2023 von 17:00 bis 18:00

This manuscript must either be drastically reduced or fully oxidized—scientific publishing from 1980 - 2030 . Scientific publishing has undergone in less than a generation a transformation from an all paper-and-print based to a fully digital/online business. In the future artificial intelligence will bring about further significant changes affecting authors, referees, and readers alike. From 1980 until today the number of annually published scientific manuscripts has increased from ca. 450.000 to ca. 4.5 Mio. 10% of which originate from chemistry. This growth is at the origin of discussions about all aspects of scientific publishing including peer review, open access and ethical problems. The lecture will touch on many of the issues and will provide facts and figures as well as food for thought—interspersed with anecdotes from the life of an Editor.

GDCh-Kolloquium Prof. Dr. Oliver Reiser
07.11.2023 von 17:00 bis 18:00

Copper makes the difference: Developing Sustainable Photoredox Catalyzed Transformations Synthetic organic chemistry undertakes significant efforts to develop new catalytic transformations that utilize greener reagents and avoid stoichiometric additives. In this regard, visible-light photoredox catalysis offers a unique activation mode of molecules, which serves as an alternative to many thermal transition-metals catalyzed reactions. The vast majority of photoredox-catalyzed processes capitalizes on heavy metals, namely, Ru(II) or Ir(III)-complexes which can serve as single electron oxidants or reductants in their photoexcited states.

GDCh-Kolloquium Prof. Dr. Tsuyoshi Kato
28.11.2023 von 17:00 bis 18:00

Low-valent silicon complexes and their analogues: surprising and peculiar behaviors For over ten years, we have been developing the chemistry of low-value silicon complexes with a unique phosphine ligand system. These complexes exhibit special properties (somewhat like transition metals). When this ligand system is applied to synthesize other stable complexes of low-valent main-group elements, they also exhibit peculiar and surprising behaviors, allowing us to develop even more amusing chemistry. In my talk, I'll present some recent results on their chemistry.

GDCh-Kolloquium Prof. Dr. Carole Duboc
12.12.2023 von 17:00 bis 18:00

Bio-inspired catalysts for clean H<sub>2</sub> production Hydrogen production through water splitting emerges as a pertinent solution in the long run for renewable energy storage. Hydrogenases, which are organometallic enzymes containing iron and/or nickel metal centers, exhibit catalytic performances that rival platinum for hydrogen evolution. Their fascinating properties make them the ideal inspiration for designing molecular catalysts for technological devices. During this presentation, the bio-inspired strategy will be illustrated: How can this approach be at the origin of efficient systems that achieve H<sub>2</sub> production in a catalytic manner? How can it provide helpful information regarding the catalytic mechanism of the enzymes?

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