Pd‐Catalyzed Functionalization of the Thenoyltrifluoroacetone Coligands by Aromatic Dyes in Bis(cyclometallated) Ir<sup>III</sup> Complexes: From Phosphorescence to Fluorescence?­

Dang, Tung T.; Bonneau, Mickaële; Williams, J. A. Gareth; Bozec, Hubert Le; Doucet, Henri; Guerchais, Véronique

doi:10.1002/ejic.201500227

Cited by 11 publications

(5 citation statements)

References 58 publications

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“…[1,9,17,23,24,26,27] The complexes containing β-diketonate ligands as L^L chelates are an important part of this family of emitters. [5,[28][29][30][31][32] These type of compounds differ from the other complexes containing neutral chelates (for example, aromatic diimines) by zero complex charge and stronger (covalent/electrostatic) binding to metal center. The simplest from the synthetic viewpoint and widely used β-diketonate ligands are symmetrical and do not contain the substituents with developed aromatic systems, [8,29,32,33] that prevents effective contribution of these ligands into MLCT or LC excited states due to high energy of their LUMO orbitals.…”

Section: Introductionmentioning

confidence: 99%

Red‐to‐NIR Iridium(III) Emitters: Synthesis, Photophysical and Computational Study, the Effects of Cyclometallating and β‐Diketonate Ligands

et al. 2021

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In this work nine novel heteroleptic Ir(III) complexes of general formulae [Ir(N^C#) 2 (O^O#)] containing four different cyclometallating and four β-diketonate ligands were synthesized and fully characterized. Six of them display phosphorescence in the deep red and NIR regions with quantum yields reaching 24.6 % in degassed solution for one of the NIR emitters. Variation in the nature of orthometalating ligands results in dramatic changes in photophysical behavior: the compounds containing 2phenylpyridine (N^C1) and 2-(benzo[b]thiophen-2-yl)pyridine ( N^C2) ligands give non-emissive complexes, whereas those with methyl 2-phenylquinoline-4-carboxylate (N^C3) and 6-(benzo[b]thiophen-2-yl)phenanthridine) (N^C4) are luminescent, but display different character of electronic transitions respon-sible for absorption and emission. Complexes with the N^C3 ligand luminesce from 3 LC excited state and do not change their emission characteristics upon variations in the nature of βdiketonates. On the contrary, the compounds based on the N^C4 cyclometalating ligand emit from the excited state with considerable contribution of 3 MLCT character and show systematic bathochromic shift of absorption and emission bands upon increase in electron donicity of O^O# ligands. This conclusion was supported by DFT and TD-DFT calculations and by the analysis of correlations between the 13 C chemical shift of the diketonate C(H) carbon and emission maxima of the compounds under study.

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Section: Introductionmentioning

confidence: 99%

Red‐to‐NIR Iridium(III) Emitters: Synthesis, Photophysical and Computational Study, the Effects of Cyclometallating and β‐Diketonate Ligands

et al. 2021

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“…As a consequence, the spectra of the four compounds are similar, which is consistent with almost identical DFT-calculated HOMO−LUMO gaps (3.13−3.18 eV). In contrast, the groups of Ziessel and Castellano 23 and Doucet and Guerchais 24 have observed that the incorporation of a polyaromatic fragment to the β-diketonate ligand of related 2-phenylpyridine complexes has a dramatic influence on the photophysical properties of the resulting iridium derivatives. Vibronic structure of the spectra, particularly in MeTHF at 77 K, is consistent with the contribution of ligand-centered 3 π−π* transitions to the excited states in addition to 3 MLCT.…”

Section: ■ Results and Discussionmentioning

confidence: 93%

Insertion of Unsaturated C–C Bonds into the O–H Bond of an Iridium(III)-Hydroxo Complex: Formation of Phosphorescent Emitters with an Asymmetrical β-Diketonate Ligand

et al. 2020

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Structural Analysis of Complexes 4, 5, and 7 S3 Computational Details S5 Energies of Optimized Structures S5 UV-vis Spectra of Complexes 4-7 (Observed and Calculated) S9 Analysis of Computed UV/Vis Data for 4-7 S10 Cyclic Voltammograms of Complexes 4-7 S15 Theoretical Analysis of Molecular Orbitals of Complexes 4-7 S16 Normalized Excitation and Emission Spectra of Complexes 4-7 S25 NMR Spectra of Complexes 2-7 S29 References S42 S3 Experimental Section: General Information. All reactions were carried out with rigorous exclusion of air using Schlenk-tube techniques. Solvents were dried by the usual procedures and distilled under argon prior to use or obtained oxygen-and water-free from an MBraun solvent purification apparatus. C, H, and N analyses were carried out in a Perkin-Elmer 2400B SeriesII-Analyzer. High-resolution (HRMS) were acquired using a MicroTOF-Q hybrid quadrupole time-of-flight spectrometer (Bruker Daltonics, Bremen, Germany). MALDI-TOF mass spectra were acquired using a Bruker Autoflex III, MALDI-TOF/TOF equipped with a DCTB matrix. IR spectra were measured using a PerkinElmer Spectrum 100 FT-IR spectrometer, equipped with an ATR accessory, as pure solids. 1 H and 13 C{ 1 H} NMR spectra were recorded on a Bruker Avance 300 or 400 MHz instrument. Chemical shifts (expressed in parts per million) are referenced to residual solvent peaks. Coupling constants J are given in hertz. UV-visible spectra were registered on an Evolution 600 spectrophotomer. Steady-state photoluminescence spectra were recorded on a Jobin-Yvon Horiba Fluorolog FL-3-11 spectrofluorimeter. Lifetimes were measured using an IBH 5000F coaxial nanosecond flash lamp. Quantum yields were measured using the Hamamatsu Absolute PL Quantum Yield Measurement System C11347-11. Cyclic voltammetry measurements were performed using a Voltalab PST050 potentiostat with Pt wire as working electrode, Pt wire as counter electrode, and saturated calomel (SCE) as reference electrode. The experiments were carried out under argon in dichloromethane or acetonitrile solutions (10-3 M), with Bu 4 NPF 6 as supporting electrolyte (0.1 M). Scan rate was 100 mV s-1. The potentials were referenced to the ferrocene/ferrocenium (Fc/Fc +) couple. Preparation of [Ir(μ-Cl)(κ 2-C,N-C 6 H 4-isoqui) 2 (1). A suspension of [Ir(μ-Cl)(η 2-COE) 2 ] 2 (500 mg, 0.56 mmol) in 10 mL of 2-ethoxyethanol was treated with 1phenylisoquinoline (470 mg, 2.30 mmol) and the mixture was refluxed for 12 h. The resulting suspension was filtered and the red solid was washed with diethyl ether (3 x 10 mL). Yield: 620 mg (87%). 1 H NMR (300 MHz, CD 2 Cl 2 , 298 K): δ 9.00 (m, 4H), 8.20 (d,

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“…Since the Claisen condensation is accompanied by formation of side products, purification of a diketone is usually difficult. Steam distillation of the reaction mixture followed by precipitation of metal (Cu, Mg, Mn, Fe) chelates and their acidic decomposition [22–23] or preparative chromatography [33–34] were used to obtain a pure product. We have found that in most cases, simple vacuum distillation of the crude reaction mixture is sufficient to obtain pure β-diketones with fluorinated side-chain.…”

Section: Resultsmentioning

confidence: 99%

A convenient and practical synthesis of β-diketones bearing linear perfluorinated alkyl groups and a 2-thienyl moiety

Taydakov¹,

Kreshchenova²,

Dolotova³

2018

Beilstein J. Org. Chem.

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A versatile and robust synthetic protocol for the preparation of β-diketones bearing 2-thienyl and perfluorinated alkyl radicals of different length or a methyl group was developed. This protocol is suitable for the preparation of multigram quantities of diketones without cumbersome purification procedures. Moreover, the known method for purification of diketones via copper chelates was improved considerably.

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Pd‐Catalyzed Functionalization of the Thenoyltrifluoroacetone Coligands by Aromatic Dyes in Bis(cyclometallated) Ir^III Complexes: From Phosphorescence to Fluorescence?

Cited by 11 publications

References 58 publications

Red‐to‐NIR Iridium(III) Emitters: Synthesis, Photophysical and Computational Study, the Effects of Cyclometallating and β‐Diketonate Ligands

Red‐to‐NIR Iridium(III) Emitters: Synthesis, Photophysical and Computational Study, the Effects of Cyclometallating and β‐Diketonate Ligands

Insertion of Unsaturated C–C Bonds into the O–H Bond of an Iridium(III)-Hydroxo Complex: Formation of Phosphorescent Emitters with an Asymmetrical β-Diketonate Ligand

A convenient and practical synthesis of β-diketones bearing linear perfluorinated alkyl groups and a 2-thienyl moiety

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Pd‐Catalyzed Functionalization of the Thenoyltrifluoroacetone Coligands by Aromatic Dyes in Bis(cyclometallated) IrIII Complexes: From Phosphorescence to Fluorescence?­

Cited by 11 publications

References 58 publications

Red‐to‐NIR Iridium(III) Emitters: Synthesis, Photophysical and Computational Study, the Effects of Cyclometallating and β‐Diketonate Ligands

Red‐to‐NIR Iridium(III) Emitters: Synthesis, Photophysical and Computational Study, the Effects of Cyclometallating and β‐Diketonate Ligands

Insertion of Unsaturated C–C Bonds into the O–H Bond of an Iridium(III)-Hydroxo Complex: Formation of Phosphorescent Emitters with an Asymmetrical β-Diketonate Ligand

A convenient and practical synthesis of β-diketones bearing linear perfluorinated alkyl groups and a 2-thienyl moiety

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Pd‐Catalyzed Functionalization of the Thenoyltrifluoroacetone Coligands by Aromatic Dyes in Bis(cyclometallated) Ir^III Complexes: From Phosphorescence to Fluorescence?