Transient absorption spectrometer

• Subject Area: Molecular Chemistry
• Term: Funded in 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 437688665

The group of Prof. Dr. Andreas Steffen has focussed on the synthesis and photophysical investigation of d10 transition metal complexes of highly abundant elements such as copper, silver and zinc, and their application in light-emitting devices, as sensors and photocatalysts. The appointment of Prof. Steffen at the TU Dortmund is expected to strengthen the activities in the area of functional materials. In order to realize the proposed work and projects, which will be briefly summarized in the following, the purchase of a transient absorption spectrometer is mandatory and the TU Dortmund strongly supports this application.Many of the photoactive metal complexes of interest show, apart from efficient triplet state population, thermally activated delayed fluorescence, by which beneficial fast lifetimes and high luminescence efficiencies can be realized. Also, we realized that multimetallic complexes can emit from several excited states in parallel, which led to the development of molecular white light emitters and stimulus-responsive materials. In another project, highly efficient photocatalysts for borylation and hydroamination reactions based on energy transfer have been developed by a detailed analysis of the excited state properties of the sensitizer units.In order to gain control and to allow for target-oriented design of the excited states with regard to lifetime, energy, efficiency and reactivity, the elucidation not only of the emission properties, but of the population paths including the presence of intermediary states and emission mechanisms of the excited states is of utmost importance. Only then structure-property relationships can be formulated and subsequently ultrafast emitters, highly efficient photocatalysts and sensors can be developed for applications. For a thorough understanding of the intersystem-crossing, internal conversion, energy transfer and single-electron transfer processes, as well as of the intermediates in photocatalytic conversions, kinetic studies of the photoexcited states with a transient absorption spectrometer are absolutely mandatory.An added value results from the purchase of this major instrument due to planned specific collaborations with the groups of Prof. Dr. Guido Clever and Prof. Dr. Carsten Strohmann at the TU Dortmund. The group of Prof. Clever published their first forays in to the field of chiral luminescent platinum complexes as well as of photoactive supramolecular cage structures, and in the future they will investigate photoswitchable and –responsive structures together with the group of Prof. Steffen. With the purchase of the transient absorption spectrometer, the group of Prof. Strohmann has the opportunity to study luminescent copper halide cluster compounds and coordination polymers on-site, so that even highly sensitive compounds can be measured with regard to their photokinetic behaviour.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Transientes Absorptionsspektrometer
• Instrumentation Group: 1810 Atomabsorptions-Spektrophotometer und Spezialzubehör
• Applicant Institution: Technische Universität Dortmund
• Leader: Professor Dr. Andreas Steffen