University of Bremen

60 University of Bremen - Research https://www.uni-bremen.de/en/neudecker-group/research University, Bremen, Chemistry, Theoretical Chemistry, Research, Working group, Stauch en University of Bremen Sat, 16 May 2026 20:23:53 +0200 Sat, 16 May 2026 20:23:53 +0200 University of Bremen content-203297 Thu, 16 Apr 2026 10:52:58 +0200 Multiscale Mechanochemistry https://www.uni-bremen.de/en/neudecker-group/research#c203297 The effect of mechanical force on chemical substances is known as mechanochemistry. Molecules can, for example, be mechanically distorted in an atomic force microscope or an ultrasound bath, thereby changing their spectroscopic properties. This effect is used&nbsp;in mechanochromic materials, which change color when a certain force is exceeded. In our group, we develop&nbsp;multiscale&nbsp;simulation methods for chemical substances under the influence of mechanical force and use these methods to gain a molecular understanding of mechanochemical processes. Featured Paper: S. Kumar, B. Demir, A. Dellwisch, L. Colombi Ciacchi, T. Neudecker, “<a href="https://pubs.acs.org/doi/full/10.1021/acs.macromol.3c01322" title="Öffnet externen Link in neuem Fenster" target="_blank">Multiscale Mechanochemical Modeling of Spiropyran-Merocyanine Isomerization in Linear PMMA Polymers</a>”,&nbsp;Macromolecules&nbsp;2023,&nbsp;56,&nbsp;8438-8447. Content content-203296 Thu, 16 Apr 2026 11:09:31 +0200 Molecules Under Pressure https://www.uni-bremen.de/en/neudecker-group/research#c203296 Molecules can be subjected to hydrostatic pressure in a diamond anvil cell. As in the case of mechanical forces, the structural and spectroscopic properties of the molecules change during this process. Changes in the electronic properties of metal complexes, for example, play an important role in the separation, storage and activation of various gases. We develop quantum chemical methods for the calculation of these effects (e.g. <a class="externalLink" href="https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/cphc.201900853" target="_blank">HCFF</a>, <a class="externalLink" href="https://aip.scitation.org/doi/10.1063/5.0024671" target="_blank">X-HCFF</a> and <a class="externalLink" href="https://pubs.acs.org/doi/pdf/10.1021/acs.jctc.0c01212" target="_blank">GOSTSHYP</a>) and develop materials that perform&nbsp;a desired switching process under pressure. In our <a class="externalLink" href="https://wires.onlinelibrary.wiley.com/doi/epdf/10.1002/wcms.1708" title="Opens external link in new window" target="_blank">review article</a> we present various simulation methods for high-pressure chemistry. Featured Paper: R. Weiß, F. Zeller, T. Neudecker, “<a href="https://doi.org/10.1063/5.0189887" title="Öffnet externen Link in neuem Fenster" target="_blank">Calculating High-Pressure Vibrational Frequencies Analytically with the Extended Hydrostatic Compression Force Field Approach</a>”,&nbsp;J. Chem. Phys.&nbsp;2024,&nbsp;160, 084101 Content content-203295 Thu, 16 Apr 2026 11:05:45 +0200 Emergent Properties https://www.uni-bremen.de/en/neudecker-group/research#c203295 How large does a molecular cluster need to be in order to show the properties of the macroscopic material? This question is surprisingly difficult to answer, as it depends on the chemical system under investigation and the observable to be reproduced. Properties that are encoded at the molecular level but only show up in molecular clusters of sufficient size are called emergent properties. In our group, we investigate emergent properties, e.g., in the field of <a class="externalLink" href="https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/cphc.202200414" title="Opens external link in new window" target="_blank">high-pressure chemistry</a>. A recently published <a class="externalLink" href="https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/cphc.202200414" title="Opens external link in new window" target="_blank">perspective article</a> summarizes different types of emergent properties that are of interest in chemistry. Featured Paper: N. Sieroka, T. Lossau, T. Neudecker, "<a href="https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/chem.202303868" title="Öffnet externen Link in neuem Fenster" target="_blank">Emergent Properties in Chemistry - Relating Molecular Properties to Bulk Behavior</a>", Chem. Eur. J.&nbsp;2024,&nbsp;30, e202303868. In other media: BBC broadcast&nbsp;CrowdScience: "Is water wet?" March 2025. Listen to it on the <a class="externalLink" href="https://www.bbc.co.uk/programmes/w3ct5rjk" title="Opens external link in new window" target="_blank">BBC website</a> or via <a class="externalLink" href="https://open.spotify.com/episode/2XGmFMYf2JZImg0wa5nDBe?si=bdbe96036e2e42e5" title="Opens external link in new window" target="_blank">podcast</a>. Content