Enantiopure, luminescent, cyclometalated Ir(<scp>iii</scp>) complexes with N-heterocyclic carbene-naphthalimide chromophore: design, vibrational circular dichroism and TD-DFT calculations

Amouri, Hani; Crassous, Jeanne; Cooksy, Andrew L.; Rager, Marie Noëlle; Vanthuyne, Nicolas; Barbieri, Andrea; Moncada, Alejandra Saavedra; Montier-Sorkine, Eve; Cheng, Ying-Sheng; Lopez, Amalia C.; Jean, Marion; Groué, Antoine

doi:10.1039/d1dt04006e

Cited by 11 publications

(11 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most relevant tris-chelates bearing C∧C* ligands are homoleptic Ir(III) complexes mer / fac -[Ir(C∧C*) 3 ] ,,, and mixed-carbene variations, which can achieve blue phosphorescent emissions, thanks to the large π–π* gap of the ligands. Heteroleptic tris-chelates of the type [Ir(C∧C*)(C∧N) 2 ] have also been reported, in which the arylcarbene acts as a supporting, nonchromophoric ligand, whereas the emission is mostly determined by the C∧N ligands, ,,− except for a few cases that incorporate C∧C* ligands featuring low π–π* gaps. − However, very few heteroleptic tris-chelates bearing two C∧C* ligands are known, which include complexes [Ir(C*∧C∧C∧C*)(C∧N)] bearing a bis-aryl-NHC and [Ir(C∧C*) 2 (N∧N)] or [Ir(C∧C*) 2 (N∧N)] + , where N∧N is a pyridylpyrazolate, pyridyltriazolate, pyridylbenzimidazolate, − or bipyridyl . Such systems are interesting because the Ir(C∧C*) 2 subunit functions as a robust platform for the development of efficient emitters whose properties can be tuned by incorporating different chromophoric C∧N or N∧N ligands.…”

Section: Introductionmentioning

confidence: 99%

Phosphorescent Tris-cyclometalated Pt(IV) Complexes with Mesoionic N-Heterocyclic Carbene and 2-Arylpyridine Ligands

2022

View full text Add to dashboard Cite

The synthesis, structure, photophysical properties, and electrochemistry of the first series of Pt(IV) tris-chelates bearing cyclometalated aryl-NHC ligands are reported. The complexes have the general formula [Pt(trz) 2 (C∧N)] + , combining two units of the cyclometalated, mesoionic aryl-NHC ligand 4-butyl-3-methyl-1-phenyl-1 H -1,2,3-triazol-5-ylidene (trz) with a cyclometalated 2-arylpyridine [C∧N = 2-(2,4-difluorophenyl)pyridine (dfppy), 2-phenylpyridine (ppy), 2-( p -tolyl)pyridine (tpy), 2-(2-thienyl)pyridine (thpy), 2-(9,9-dimethylfluoren-2-yl)pyridine (flpy)], and presenting a mer arrangement or metalated aryls. They exhibit a significant photostability under UV irradiation and long-lived phosphorescence in the blue to yellow color range, arising from 3 LC excited states involving the C∧N ligands, with quantum yields of up to 0.34 in fluid solution and 0.77 in the rigid matrix at 298 K. The time-dependent density functional theory (TD-DFT) calculations reveal that nonemissive, deactivating excited states of ligand-to-metal charge-transfer (LMCT) character are pushed to high energies as a consequence of the strong σ-donating ability of the carbenic moieties, making the Pt(trz) 2 subunit an essential structural component that enables efficient emissions from the chromophoric C∧N ligands, with potential application for the development of different Pt(IV) emitters with tunable properties.

show abstract

Section: Introductionmentioning

confidence: 99%

Phosphorescent Tris-cyclometalated Pt(IV) Complexes with Mesoionic N-Heterocyclic Carbene and 2-Arylpyridine Ligands

2022

View full text Add to dashboard Cite

show abstract

“…For all the complexes, a weak and broad absorption band above 370 nm was observed, which is attributed to metal-to-ligand charge transfer (MLCT) transitions, along with ligandcentered (LC) contribution from the ligands. In addition to these transitions, a long tail extended to the visible region can be attributed to the strong spin-orbit coupling (SOC) applied by the Ir atom, which can cause the direct singlet-triplet transition [2,6,23,[31][32][33]. The Rh(III) derivative 4 displayed a similar envelope of absorption bands, with the obvious absence of the low energy singlet-triplet direct absorption above 380 nm [34].…”

Section: Luminescence Propertiesmentioning

confidence: 99%

“…Cyclometalated iridium (III) complexes are an important class of molecules because they display remarkable photophysical properties [1] for a wide range of applications [2][3][4][5][6][7]. Moreover, they show high stability, which makes them adequate emitters for organic lightemitting devices (OLEDs) [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Rational Design of Mono- and Bi-Nuclear Cyclometalated Ir(III) Complexes Containing Di-Pyridylamine Motifs: Synthesis, Structure, and Luminescent Properties

et al. 2022

View full text Add to dashboard Cite

Heteroleptic cyclometalated iridium (III) complexes (1–3) containing di-pyridylamine motifs were prepared in a stepwise fashion. The presence of the di-pyridylamine ligands tunes their electronic and optical properties, generating blue phosphorescent emitters at room temperature. Herein we describe the synthesis of the mononuclear iridium complexes [Ir(ppy)2(DPA)][OTf] (1), (ppy = phenylpyridine; DPA = Dipyridylamine) and [Ir(ppy)2(DPA-PhI)][OTf] (2), (DPA-PhI = Dipyridylamino-phenyliodide). Moreover, the dinuclear iridium complex [Ir(ppy)2(L)Ir(ppy)2][OTf]2 (3) containing a rigid angular ligand “L = 3,5-bis[4-(2,2′-dipyridylamino)phenylacetylenyl]toluene” and displaying two di-pyridylamino groups was also prepared. For comparison purposes, the related dinuclear rhodium complex [Rh (ppy)2(L)Rh(ppy)2][OTf]2 (4) was also synthesized. The x-ray molecular structure of complex 2 was reported and confirmed the formation of the target molecule. The rhodium complex 4 was found to be emissive only at low temperature; in contrast, all iridium complexes 1–3 were found to be phosphorescent in solution at 77 K and room temperature, displaying blue emissions in the range of 478–481 nm.

show abstract

“…In order to study the importance of the dfppy cyclometalated ligand in the emission properties, 6, with the highest emission strength, was selected. When dfppy in 6 is replaced by ppy, 6′, the emission strength 51 is intensely reduced and the bands are markedly redshifted (Figure S19).…”

Section: ■ Introductionmentioning

confidence: 99%

Fine-Tuning of Luminescence Properties of Cyclometalated Platinum(II) Complexes via Aminopyridine Derivatives

et al. 2022

View full text Add to dashboard Cite

The present work describes two families of cycloplatinated(II) complexes [PtR(dfppy)(L)], dfppy = 2-(2,4-difluorophenyl)pyridinate, R = Me and p-MeC 6 H 4 and L = pyridine, py, and aminopyridine derivatives, x-NH 2 -py, x = 2, 3, and 4. The complexes show similar UV−vis spectra possessing intense bands in the 250−400 region, which are assigned as π−π* transitions and mixed metal-to-ligand charge transfer (MLCT)/π−π*. The MLCTs are observed as weak broad bands in the range 400−500 nm. Meanwhile, structured emission bands are observed for the complexes in the range 450−600 nm with quantum efficiencies up to 0.7, wherein the p-MeC 6 H 4 derivatives show higher emission strengths compared to their Me-containing counterparts. Moreover, the NH 2 position on the pyridine significantly affects the emission efficiency of the Me derivatives and conversely does not show a large impact on the emission intensity of the p-MeC 6 H 4 -containing complexes. DFT and TD-DFT calculations reveal that 3 π−π* (dfppy)/ 3 MLCT are responsible for the emissions in the Me complexes. However, in the p-MeC 6 H 4 complexes, the emissions originate from 3 L″LCT and 3 MLCT (L = dfppy, L″ = p-MeC 6 H 4 ).

show abstract

Enantiopure, luminescent, cyclometalated Ir(iii) complexes with N-heterocyclic carbene-naphthalimide chromophore: design, vibrational circular dichroism and TD-DFT calculations

Abstract: A series of chiral cyclometalated iridium complexes of the type [Ir(C^N)2(C^C:)], {(C^N) = ppy (2); dfppy (3)} featuring a naphthalimide N-heterocyclic carbene ligand (C^C:) = (Naphthalimide-NHC) are described and...

Cited by 11 publications

References 38 publications

Phosphorescent Tris-cyclometalated Pt(IV) Complexes with Mesoionic N-Heterocyclic Carbene and 2-Arylpyridine Ligands

Phosphorescent Tris-cyclometalated Pt(IV) Complexes with Mesoionic N-Heterocyclic Carbene and 2-Arylpyridine Ligands

Rational Design of Mono- and Bi-Nuclear Cyclometalated Ir(III) Complexes Containing Di-Pyridylamine Motifs: Synthesis, Structure, and Luminescent Properties

Fine-Tuning of Luminescence Properties of Cyclometalated Platinum(II) Complexes via Aminopyridine Derivatives

Contact Info

Product

Resources

About