Immobilisation interaction between photoactive Cu(I)-complexes and polymeric matrices studied computationally and experimentally
Physical Chemistry of Solids and Surfaces, Material Characterisation
Theoretical Chemistry: Molecules, Materials, Surfaces
Final Report Abstract
The project studied panchromatically absorbing, non-noble metal Cu(I) complexes in polymer matrices, towards a perspective application for light harvesting and charge accumulation in solar energy storage schemes or heterogenous photoredox catalysis. During the three-months project a set of computational and experimental protocols was established that aids in the design and characterization of Cu(I) complexes in polymer matrix materials. The computational approach combined quantum mechanics and molecular dynamics calculations to successfully describe the binding and light absorption properties of an anionic Cu(I) complex in a solvent sphere as well as in a cationic block copolymer matrix. Determining the light absorption properties was found as a joint theoretical and experimental observable for method cross validation. For the investigated complexes, easily accessible solvent-dependent absorption data can be used to estimate the interactions with a polymer matrix. Furthermore, UV-Vis diffuse reflectance measurements, attenuated total reflection infrared-spectroscopy as well as X-ray photoelectron spectroscopy and thermogravimetry are suited experimental techniques to study complex loaded polymers, while electrochemical methods so far were unsuccessful. The computational treatment resulted the immobilisation at the joint of the hydrophilic and hydrophobic blocks of the matrix polymer yet with an unspecific interaction with the polar part. An important experimental outcome is the dependence of the immobilisation success on the choice of the hydrophobic block of the polymer backbone. Additionally, the experimental results suggest the design of rigid cationic binding moieties at the polymer to prevent decomplexation. The latter consideration may be of general importance for immobilisation of first-row transition metal complexes and the design of the respective polymer matrices. The gained experiences and methods are forming the basis for follow-up projects and will flow into the work of the collaborative research center CATALIGHT on light-driven catalysis in hierarchically structured materials.
