Mononuclear copper(I) complexes bearing a 3-phenyl-5-(pyridin-4-yl)-1,2,4-triazole ligand: synthesis, crystal structure, TADF-luminescence, and mechanochromic effects

Alexey Gusev; Elena Braga; Ekaterina Zamnius; Mikhail Kiskin; Amjad Ali; Glib Baryshnikov; Wolfgang Linert

doi:10.1039/d3dt02633g

Mononuclear copper(I) complexes bearing a 3-phenyl-5-(pyridin-4-yl)-1,2,4-triazole ligand: synthesis, crystal structure, TADF-luminescence, and mechanochromic effects

Dalton Trans. 2023 Oct 24;52(41):14995-15008. doi: 10.1039/d3dt02633g.

Authors

Alexey Gusev¹, Elena Braga¹, Ekaterina Zamnius¹, Mikhail Kiskin², Amjad Ali³, Glib Baryshnikov³, Wolfgang Linert⁴

Affiliations

¹ Crimean Federal University, Simferopol, 295007, Crimea, Russia. galex0330@gmail.com.
² N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
³ Linköping University, Department of Science and Technology, Laboratory of Organic Electronics, Norrköping, SE-60174, Sweden.
⁴ Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163-AC, A-1060 Vienna, Austria.

PMID: 37811719
DOI: 10.1039/d3dt02633g

Abstract

Three new mononuclear heteroleptic copper(I) halide complexes, [CuL(PPh₃)₂X] (X = Cl, Br, I), based on 3-phenyl-5-(pyridin-4-yl)-1,2,4-triazole (L) and triphenylphosphine (PPh₃) ligands, have been prepared by reaction of CuX (X = Cl, Br, I), L and PPh₃ in a molar ratio of 1 : 1 : 2 in MeCN solutions. The synthesized complexes exhibit blue light emission in solutions and bright green emission in the crystal state with quantum yields of up to 100%. The luminescence decay analysis and density functional theory calculations revealed that the emission of solid samples at room temperature corresponds to the thermally activated delayed fluorescence, while that at 77 K is assigned to phosphorescence. Utilizing the studied complexes in OLED heterostructures resulted in high-performing green-emitting devices with an external quantum efficiency of up to 13.4%.