P boolean AND N Bridged Cu(I) Dimers Featuring Both TADF and Phosphorescence. From Overview towards Detailed Case Study of the Excited Singlet and Triplet States

Hofbeck, Thomas and Niehaus, Thomas A. and Fleck, Michel and Monkowius, Uwe and Yersin, Hartmut (2021) P boolean AND N Bridged Cu(I) Dimers Featuring Both TADF and Phosphorescence. From Overview towards Detailed Case Study of the Excited Singlet and Triplet States. MOLECULES, 26 (11): 3415. ISSN , 1420-3049

Full text not available from this repository. (Request a copy)

Abstract

We present an overview over eight brightly luminescent Cu(I) dimers of the type Cu2X2(P boolean AND N)(3) with X = Cl, Br, I and P boolean AND N = 2-diphenylphosphino-pyridine (Ph(2)Ppy), 2-diphenylphosphino-pyrimidine (Ph(2)Ppym), 1-diphenylphosphino-isoquinoline (Ph(2)Piqn) including three new crystal structures (Cu2Br2(Ph(2)Ppy)(3) 1-Br, Cu2I2(Ph(2)Ppyrn)(3) 2-I and Cu2I2(Ph(2)Piqn)(3) 3-I). However, we mainly focus on their photo-luminescence properties. All compounds exhibit combined thermally activated delayed fluorescence (TADF) and phosphorescence at ambient temperature. Emission color, decay time and quantum yield vary over large ranges. For deeper characterization, we select Cu2I2(Ph(2)Ppy)(3), 1-I, showing a quantum yield of 81%. DFT and SOC-TDDFT calculations provide insight into the electronic structures of the singlet S-1 and triplet T-1 states. Both stem from metal+iodide-to-ligand charge transfer transitions. Evaluation of the emission decay dynamics, measured from 1.2 <= T <= 300 K, gives Delta E(S-1-T-1) = 380 cm(-1) (47 meV), a transition rate of k(S-1 -> S-0) = 2.25 x 10(6) s(-1) (445 ns), T-1 zero-field splittings, transition rates from the triplet substates and spin-lattice relaxation times. We also discuss the interplay of S-1-TADF and T-1-phosphorescence. The combined emission paths shorten the overall decay time. For OLED applications, utilization of both singlet and triplet harvesting can be highly favorable for improvement of the device performance.

Item Type: Article
Uncontrolled Keywords: ACTIVATED DELAYED FLUORESCENCE; LIGHT-EMITTING-DIODES; DINUCLEAR COPPER(I) COMPLEXES; BASIS-SETS; PHOTOPHYSICAL PROPERTIES; CRYSTAL-STRUCTURES; EMITTERS; DESIGN; BLUE; EMISSION; dimeric copper(I) complexes; P boolean AND N phosphine ligands; X-ray structures; combined thermally activated delayed fluorescence (TADF) and phosphorescence; combined singlet and triplet harvesting; high emission quantum yields; tunability of photophysical properties; zero-field splitting (ZFS); spin-lattice relaxation (SLR); triplet substate decay components
Subjects: 500 Science > 540 Chemistry & allied sciences
Divisions: Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry III - Physical Chemistry (Molecular Spectroscopy and Photochemistry) > Prof. Dr. Hartmut Yersin
Depositing User: Dr. Gernot Deinzer
Date Deposited: 09 Sep 2022 11:15
Last Modified: 09 Sep 2022 11:15
URI: https://pred.uni-regensburg.de/id/eprint/46936

Actions (login required)

View Item View Item