Host: Local representatives Graz

Trainer: Assoc. Prof. Dr. Heidi Annemarie Schwartz

Date: 1/11/2023

Time: 17:15

Place: online and TU Graz, HS H, Kopernikusgasse 24, 8010 Graz

Language: German

Deadline for registration: 1/10/2023

Since their discovery, Metal-Organic Frameworks (MOFs) have been considered for various applications to take advantage of their porosity. Exploiting them as host materials for photoactive dyes is a relatively young research field, giving rise to new functional materials with unprecedented properties. By forming two-component systems with the photoactive molecule being non-covalently attached to the host framework, transmission of the properties of the photoswitch in dissolved state to the solid phase is feasible. Thus, e.g., solid state photoswitching is enabled. Within the framework of spiropyrans and azobenzene derivatives as guest molecules, the occurring optical properties of the overall system were studied as a function of a) host structure, b) guest substitution pattern, and c) loading amount. These three adjusting screws allow the desired properties of the two-component system to be specifically set. The local environment given by the MOF pores was found to significantly impact the photochromic and solvatochromic response of the inserted spiropyran. Further, reversibility of switching is strongly related to the nature of both MOF and spiropyran substitution. For fluorinated azobenzene derivatives, loading amount and degree of fluorination direct the photo-isomer ratio, leading to systems with almost quantitative switching. These fundamental insights into the interplay of the single components further push synthesis strategies for the systematic construction of such functional materials with technologically relevant properties.

The registration is closed.