Project Details
Projekt
P1: Stimulus-Responsive Circularly Polarized Luminescence (SR-CPL) in Linear d10 Coinage Metal Complexes
Applicant
Professor Dr. Andreas Steffen
Subject Area
Inorganic Molecular Chemistry - Synthesis and Characterisation
Term
since 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 535200000
The design of new stimulus-responsive (SR) molecular materials exhibiting emitting triplet states is of fundamental importance to provide optically functional systems for innovative photonic sensors, OLEDs, data storage and processing, or photonic switches. As a subproject of the Research Unit STIL-COCOs, this proposal is focused on the investigation of cationic two-coordinate copper(I) carbene complexes with a d10 electron configuration, which typically form linear coordination geometries. We have previously demonstrated that such compounds, forming metal-to-ligand/ligand-to-ligand charge-transfer excited states, can easily distort either upon anion association in the ground state or by exciplex formation with the counterion X when shearing forces are applied as a stimulus in the solid state. Both distortion mechanisms lead to severe changes of the photophysical properties in comparison to the non-associated structures. Coupling a photonic information content via the circularly polarized luminescence (CPL) signal with the SR of the triplet emitters, either by CPL on-off switch, change of CPL efficiency or dissymmetry direction, would provide access to completely new classes of materials and applications, and is yet unknown in the literature. In this project we aim to establish structure-property relationships for efficient SR-CPL from linear copper(I) emitters based on cation-anion exciplex formation or initiation/disruption of ion pairing as stimulus response in dependence of medium and environment. For control and optimization of the SR process and the resulting photophysical parameters, a thorough understanding of the structural and environmental effects is mandatory and will be developed in a highly interdisciplinary approach. This involves investigation of various stimuli, such as pressure (P), stress (F), magnetic (B), electric (E) fields, in a variety of matrices, such as solution, crystalline solid, organic films and MOFs. The assessment of the SR behavior and optimization of the resulting photophysical read-out (emission wavelengths, quantum yields, lifetimes, radiative (kr) and non-radiative (knr) decay rates and chiroptical properties glum) with regard to selectivity, sensitivity and reversibility of the response will be studied by a multidisciplinary approach with all collaborators of the FOR being involved.
DFG Programme
Research Units
