Concepts Guiding Joint Theoretical and Experimental Approaches from Bioimaging to Catalysis and Efficient Light Harvesting

Seminar of the Department of Nanocatalysis to be presented by Prof. Vlasta Bonačić-Koutecký of the University Split and Humboldt University Berlin

Abstract:

Theoretical investigation of the linear and nonlinear optical properties of ligand-protected low nuclearity noble metal clusters will be first presented. In this context theoretical approaches for reliable description of two-photon absorption spectra will be addressed. Goal is to design species exhibiting strong one-photon and/or two-photon absorption and emission in the UV-VIS spectral range. We will show that the optical properties can be tuned by creating the appropriate interplay between electronic excitations within the cluster core and selected prototype of ligands. Comparison with available experimental results will be discussed. We conclude that such low nuclearity protected noble metal clusters are promising for bio-labelling and imaging as alternatives to the standard fluorescent probes such as quantum dots or organic dyes.

Second, we present our study of small coinage metal hydride ligated nanoclusters showing their capability to release the hydrogen. We propose the concept of synergistic role of ligand and substrate in catalysis on example of formic acid. This new catalyst neatly fits into a zeolite which does not perturb reactivity, thus providing a unique example on how “heterogenization” of a homogenous catalyst for the selective catalyzed extrusion of carbon dioxide from formic acid can be achieved, with important application in hydrogen storage and in situ generation of H2. The above results motivated us to investigate the selective decomposition of formic acid driven by highly porous zirconium-based metal- organic framework with catalytic active site located at the organic linker with aim to design new materials for the heterogenous catalysis. Thus, we illustrated that unique optical and reactivity properties of ligated noble metal clusters which can be tuned by appropriate interplay between metallic and organic subunits have significant potential for different applications.

Third, the design of new materials for transparent luminescent concentrators based on acceptor- substituted squaraine dyes will be addressed.