Related Experiment Video
Updated: Mar 10, 2026
The Effect of Ultraviolet Radiation on the Chemical Bath Deposition of Bisthiourea Cadmium Chloride Crystals and the Subsequent CdS Obtention
Published on: August 30, 2018
Influence of Imidazole Substituent Bulkiness on [CuI(PPh3)2N] Complexes with TADF Blue Solid-State Emission
Carolina Francener1,2, Giliandro Farias3, Renê Santos de Amorim1
1Universidade Federal de Santa Catarina, Department of Chemistry, R. Agronomico Andrei Cristian Ferreira, Florianópolis 88040-900, Brazil.
Abstract:
Copper-(I) heteroleptic complexes with phosphine- and nitrogen-containing ligands are well-known thermally activated delayed fluorescence (TADF) emitters and are of interest for OLED applications due to their cost-effectiveness. In this work, we report the design and synthesis of a series of novel Cu-(I) complexes featuring triphenylphosphine- and imidazole-based ligands functionalized with varying alkyl chains. This allowed for the evaluation of purely monodentate ligand systems and the impact of the ligand bulkiness on the photophysical properties. Time-resolved spectroscopy, combined with temperature-dependent measurements, revealed blue solid-state emission and confirmed the TADF behavior across the series. Room-temperature lifetimes reached as low as 0.5 μs, facilitated by small singlet-triplet energy gaps ΔE (S1-T1) between 110 and 60 meV. Bulky ligands led to the smallest S-T gaps. A decrease in phosphorescence lifetimes with increasing alkyl chain size suggested enhanced spin-orbit coupling (SOC), attributed to a more tetrahedral coordination environment. Quantum chemical calculations revealed that the imidazole moiety does not participate directly in the frontier molecular orbitals, indicating that the alkyl chains primarily influence the emission by modulating the geometry around the Cu-(I) center.
More Related Videos
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
12:19Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
Published on: November 29, 2018
Related Concept Videos
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
01:26Variables Affecting Phosphorescence and Fluorescence
02:42Valence Bond Theory
01:18Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...