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  • Computationally Modeling Photoluminescence and Charge Transfer in Copper (I) bis(phenanthroline) Transition Metal Complexes

This content will become publicly available on February 22, 2026

Title: Computationally Modeling Photoluminescence and Charge Transfer in Copper (I) bis(phenanthroline) Transition Metal Complexes
Transition metal complexes are an ideal target system for the computational modeling of photoluminescence to further improve their applications as emitters. In addition to strongly absorbing visible light, their photoactivity is highly tunable due to a wide selection of ligands which can modify the nature of photoinduced charge transfer (CT) in the system. For photochemical purposes, a long-lived CT state is ideal. This is exemplified by ruthenium(II) tris(bipyridine), which achieves such a state by undergoing intersystem crossing (ISC) due to the large spin-orbit coupling (SOC) for the ruthenium metal center’s d-electrons.1 The mechanism by which the CT state’s long lifetime is achieved is through flipping the spin of the electron in the excited state, which makes for a spin-forbidden relaxation. Despite these strengths, ruthenium remains very cost-prohibitive due to its small natural abundance compared to other transition metals. For this reason, several analogs to copper(I) bis(phenanthroline) have been studied as systems that exhibit CT state lifetimes similar to those in ruthenium (II) tris(bipyridine).2 These analogs seek to improve the CT character of copper(I) bis(phenanthroline) by functionalization with electron withdrawing groups and by extending the ligands’ π-systems. This study employs density- functional theory (DFT) as a basis for the computation of photoinduced CT lifetimes and quantum yields by factoring in spin-polarization and SOC, while operating under the framework of Redfield theory.3 This treatment couples the system to a heat bath and moreover allows for the simulation of dynamics using a reduced density matrix. Redfield dynamics enables the simulation of CT state lifetimes with the inclusion of spin effects. Non-adiabatic couplings (NACs), calculated using an “on-the-fly” technique, are used to extract Redfield tensors which may then be used in the simulation of electronic relaxation over time. It is expected that both electron withdrawing groups and extensions to the ligands’ π-systems would increase the lifetime and quantum yield of photoluminescence. References: (1) (2) (3) Caspar, J. V.; Meyer, T. J. Photochemistry of Tris(2,2’-Bipyridine)Ruthenium(2+) Ion (Ru(Bpy)32+). Solvent Effects. J. Am. Chem. Soc. 1983, 105 (17), 5583–5590. https://doi.org/10.1021/ja00355a009. Lavie-Cambot, A.; Cantuel, M.; Leydet, Y.; Jonusauskas, G.; Bassani, D. M.; McClenaghan, N. D. Improving the Photophysical Properties of Copper(I) Bis(Phenanthroline) Complexes. Coordination Chemistry Reviews 2008, 252 (23–24), 2572–2584. https://doi.org/10.1016/j.ccr.2008.03.013. Redfield, A. G. The Theory of Relaxation Processes. In Advances in Magnetic and Optical Resonance; Elsevier, 1965; Vol. 1, pp 1–32. https://doi.org/10.1016/B978-1-4832-3114-3.50007-6.  more » « less
Award ID(s):
1800476 1944921
PAR ID:
10658105
Author(s) / Creator(s):
;
Publisher / Repository:
64th Sanibel Symposium, Quantum Theory Project, University of Florida https://sanibelsymposium.qtp.ufl.edu/2025-abstracts/
Date Published:
Format(s):
Medium: X
Location:
Sanibel Symposium, St. Augustine, FL
Sponsoring Org:
National Science Foundation
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