Positively Charged Iridium(III) Triazole Derivatives as Blue Emitters for Light‐Emitting Electrochemical Cells

Abstract

Cationic blue‐emitting complexes with (2,4‐difluoro)phenylpyridine and different 1,2,3‐triazole ligands are synthesized with different counterions. The influence of the substituents on the triazole ligand is investigated as well as the influence of the counterions. The substituents do not change the emission energy but, in some cases, slightly modify the excited‐state lifetimes and the emission quantum yields. The excited‐state lifetimes, in apolar solvents, are slightly dependent on the nature of the counterion. A crystal structure of one of the compounds confirms the geometry and symmetry postulated on the basis of the other spectroscopic data. Light‐emitting electrochemical cell devices are prepared and the recorded emission is the bluest with the fastest response time ever reported for iridium complexes.

Smart responsive phosphorescent materials for data recording and security protection

“…1b). The complexes were characterized via FTIR, 1 H NMR, 13 C NMR, 19 F NMR, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), electrospray ionization mass spectrometry (ESI-MS), (see Supplementary Figs 1-11) X-ray crystal structure analysis (see Supplementary Data 1-4 and Supplementary Table 1), UV/Vis absorption spectrometry and steady-state fluorescence spectrometry.…”

“…We envision the potential commercial applications of electrochromic luminescent materials because they can be conveniently integrated into semiconductor-based electronic devices. In addition, it is conceivable that compounds simultaneously showing mechanochromic, vapochromic and electrochromic luminescence are of great use to the development of multifunctional materials.Phosphorescent transition-metal complexes, such as those of Ir(III) and Pt(II), have been extensively studied for various photonic and electronic applications because of their rich excited-state properties, including high luminescence quantum yields, long emission lifetimes, large Stokes shifts, high photostability and various luminescence colours [17][18][19][20] . These complexes have also been utilized as external stimuli-responsive materials because of their highly sensitive photophysical properties to the microenvironment [21][22][23] .…”

Luminescent Ionic Transition‐Metal Complexes for Light‐Emitting Electrochemical Cells

“…Indeed, recent examples by De Cola and co-workers show that, by using Ir-iTMCs with 1,2,3-triazole-pyridine as ancillary ligands, PL peaks are in the range 460-490 nm and LECs exhibiting true-blue emission are obtainable; [116] one of these compounds (15) is depicted in Figure 19. Following a similar approach, Chen et al [117] used the isomeric 1,2,4-triazole-pyridine with different substituents in the 4 and 5 position of the triazole ring as the ancillary ligand to make an Ir-iTMC (16) displaying an EL band further shifted to the blue (457-486 nm).…”

“…[76] As discussed in Section 3, there are several reasons that justify their selection over Ru II complexes: 1) high PLQY; [19,86,98,156] 2) easily tunable HOMO-LUMO energy gap by independent chemical modifications of the ligands; [29,37,75,81,82,85,91,99,103,105,111,113,116,118,[157][158][159][160] 3) high stability against degradation processes owing to higher ligand-field splitting. [19,86,97,98,156,[161][162][163][164] Over the last eight years, the use of Ir-iTMCs has brought very significant advances in LEC performances, that is, color, efficiency, stability, and turn-on times.…”

Towards Water Soluble Mitochondria-Targeting Theranostic Osmium(II) Triazole-Based Complexes

“…We, and others, have paid particular attention to the use of copper-catalysed coupling of alkynes and azides to form 1,2,3-triazole-based ligands [7][8][9][10] and have investigated the photophysical properties of their resultant complexes. A significant number of reports have appeared detailing the photophysical and photochemical properties of triazole-based complexes of Re(I), Ru(II) and Ir(III) [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Examples of triazole-containing complexes of osmium(II)…”