Research

Strain analysis of 1,4-substituted triazole
Strain analysis of 1,4-substituted triazole

Quantum Mechanochemistry

Quantum Mechanochemistry is the computational investigation of molecules under the influence of external forces. Experimentally, forces can be applied to molecules by using an Atomic Force Microscope (AFM) or an ultrasound bath, thereby changing the geometries and spectroscopic properties of the molecules. This effect can be used in mechanochromic materials, i.e. materials that change their color upon mechanical deformation. In our group we investigate the structural and spectroscopic properites of molecules under mechanical force and develop mechanochromic materials.

 

Featured Paper:

S. Kumar, T. Stauch, "The activation efficiency of mechanophores can be modulated by adjacent polymer composition", RSC Adv. 2021, 11, 7391-7396.

Molecules Under Pressure

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. HCFF, X-HCFF and GOSTSHYP) and develop materials that perform a desired switching process under pressure.

 

Featured Paper:

S. Kumar, F. Zeller, T. Stauch, "A Two-Step Baromechanical Cycle for Repeated Activation and Deactivation of Mechanophores", J. Phys. Chem. Lett. 202112, 9740-9474.

Time-resolved UV/VIS spectrum of homotropylium
Time-resolved UV/VIS spectrum of homotropylium

Spectroscopic Properties

The structure of new molecules can be determined experimentally by using spectroscopic techniques. When molecules reach a certain size, however, it becomes more and more difficult to determine the structural motives of the molecules by interpreting isolated or overlapping signals in a spectrum. Quantum chemical calculations of spectroscopic properties like wavelengths and intensities are of tremendous help in the interpretation of experimental spectra. In our group we develop such methods, with a focus on NMR spectroscopy.

 

Featured Paper:

H. Schrey, T. Scheele, C. Ulonska, D. L. Nedder, T. Neudecker, P. Spiteller, M. Stadler, “Alliacane-Type Secondary Metabolites from Submerged Cultures of the Basidiomycete Clitocybe nebularis”, J. Nat. Prod. 2022, DOI: acs.jnatprod.2c00554.