Quantifying Surface-Induced Inhibition of Cu(I) Excited State Distortion Using Variable- Temperature Transient Absorption and Stern– Volmer Quenching
Year: 2026
Type: preprint
Abstract: Photoexcited Cu(I) coordination complexes are known to undergo structural distortion that lowers the excited state energy, facilitates nonradiative decay, and opens the metal center to coordinative quenching of the excited state. Strategic surface binding was recently introduced as a new means of hindering excited state distortion resulting in a >10-fold increase in excited state lifetimes. Here, Stern-Volmer analysis, temperature dependent ultrafast transient absorption, and theoretical calculations reveal a near order-of-magnitude decrease in the quenching rate constant, a decrease in reorganization energies, an increased entropic penalty to accessing the transition state geometry, and a smaller change in the dihedral angle of the triplet excited state upon surface binding. Collectively, the results support that strategic surface binding is an effective strategy for inhibiting distortion of Cu(I) coordination complexes resulting in an increased excited state lifetime, decreased accessibility of coordinative quenchers, and opens the door to increasing molecular reactivity via molecule-metal oxide interfaces.
Source: ChemRxiv
Institution: Florida State University
Language: English
Subfield: Physical and Theoretical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7212319026