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Kiseleva MA, Churakov AV, Taydakov IV, Metlin MT, Kozyukhin SA, Bezzubov SI. Aggregation-induced emission of cyclometalated rhodium(III) and iridium(III) phenylpyridine complexes with ancillary 1,3-diketones. Dalton Trans 2023; 52:17861-17872. [PMID: 37975537 DOI: 10.1039/d3dt02651e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
A joint structural and spectroscopic study of simple bis-cyclometataled rhodium(III) and iridium(III) complexes with 2-phenylpyridine and aromatic β-diketones (dibenzoylmethane, benzoylacetone, benzoyltrifluoroacetone, and 2-thenoyltrifluoroacetone) reveals an interplay between the solid-state emission efficiency and crystal packing peculiarities of the complexes. Although the prepared rhodium(III) cyclometalates are isostructural with iridium(III) analogues, different types of π-π interactions are responsible for the aggregation-induced emission (AIE) of the complexes depending on the metal ion. For iridium(III) complexes, pyridyl-pyridyl contacts are essential for AIE because they lower the energy of the emissive metal-to-ligand charge transfer state below that of the non-emissive state located at the ancillary ligand. Enabled by phenyl-pyridyl interactions partially blocking the population of non-emissive d-d states, solid-state phosphorescence enhancement is successfully achieved in a rhodium(III) complex with ancillary benzoyltrifluoroacetone, which is the first example of a rhodium complex exhibiting AIE.
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Affiliation(s)
- Marina A Kiseleva
- Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow 119991, Russia.
- Department of Chemistry, Lomonosov Moscow State University, Lenin's Hills 1, Moscow, 119991, Russia
| | - Andrei V Churakov
- Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow 119991, Russia.
| | - Ilya V Taydakov
- P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Prospect, Moscow 119991, Russia
| | - Mikhail T Metlin
- P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Prospect, Moscow 119991, Russia
- Bauman Moscow State Technical University, 2-ya Baumanskaya Str. 5/1, Moscow, 105005, Russia
| | - Sergey A Kozyukhin
- Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow 119991, Russia.
| | - Stanislav I Bezzubov
- Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow 119991, Russia.
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Tatarin SV, Kalle P, Taydakov IV, Varaksina EA, Korshunov VM, Bezzubov SI. Sterically hindered phenanthroimidazole ligands drive the structural flexibility and facile ligand exchange in cyclometalated iridium(III) complexes. Dalton Trans 2021; 50:6889-6900. [PMID: 33913992 DOI: 10.1039/d1dt00820j] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of bis-cyclometalated iridium(iii) complexes with 2-arylphenanthroimidazole "antenna" ligands containing electron-donor or withdrawing substituents and a more flexible ancillary aromatic β-diketone bearing the "anchoring" carboxymethyl function has been prepared. Thorough X-ray study of the complexes revealed significant structural strains caused by bulky cyclometalated 2-arylphenanthroimidazoles resulting in dramatic distortions of the iridium octahedron and even in twist of the phenanthrene fragment. The crystal data were corroborated by gas-phase DFT calculations whereby the geometry of the complexes was distorted in the same way. While redox potentials, absorption and emission maxima of the complexes displayed expected change upon the variation of the electron-donating ability of the cyclometalated ligands, the complexes readily exchanged the bidentate ancillary ligand in the presence of a negligible amount of protons that was inspected in solution by UV-Vis spectroscopy. Moreover, after hydrolysis of the carboxymethyl group the resulting complexes readily react with the surface of titanium dioxide giving unique binuclear structures in which the deprotonated carboxy group of the coordinated β-diketonate binds the second bis-cyclometalated unit by forming a four-membered metallacycle. Though the enhanced reactivity of the complexes is contrary to the common idea of the high inertness of iridium(iii) compounds it can be seen as a consequence of the interplay between the steric hindrance induced by the ligands and the strong preference of the iridium(iii) ion for octahedral geometry. This study demonstrates that the use of bulky ligands provides access to light-harvesting iridium(iii) complexes with required extent of lability which may be promising as photocatalysts and biologically active molecules.
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Affiliation(s)
- Sergei V Tatarin
- N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky pr. 31, Moscow 119991, Russia. and Lomonosov Moscow State University, Lenin's Hills, 1-3, Moscow, 119991, Russia
| | - Paulina Kalle
- N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky pr. 31, Moscow 119991, Russia. and Lomonosov Moscow State University, Lenin's Hills, 1-3, Moscow, 119991, Russia
| | - Ilya V Taydakov
- P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Prospect, Moscow 119991, Russia and G.V. Plekhanov Russian University of Economics, 36 Stremyanny Per., Moscow, 117997 Russian Federation
| | - Evgenia A Varaksina
- P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Prospect, Moscow 119991, Russia
| | - Vladislav M Korshunov
- P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Prospect, Moscow 119991, Russia and Bauman Moscow State Technical University, 2-ya Baumanskaya Str. 5/1, 105005, Moscow, Russia
| | - Stanislav I Bezzubov
- N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky pr. 31, Moscow 119991, Russia.
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Cazzaniga M, Cargnoni F, Penconi M, Bossi A, Ceresoli D. Ab Initio Many-Body Perturbation Theory Calculations of the Electronic and Optical Properties of Cyclometalated Ir(III) Complexes. J Chem Theory Comput 2020; 16:1188-1199. [PMID: 31860292 DOI: 10.1021/acs.jctc.9b00763] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cyclometalated Ir(III) compounds are the preferred choice as organic emitters in organic light-emitting diodes. In practice, the presence of the transition metal surrounded by carefully designed ligands allows fine-tuning of the emission frequency as well as good efficiency of the device. To support the development of new compounds, experimental measurements are generally compared with absorption and emission spectra obtained from ab initio calculations. The standard approach for these calculations is time-dependent density functional theory (TDDFT) with a hybrid exchange-correlation functional like B3LYP. Because of the size of these compounds, the application of more complex quantum chemistry approaches can be challenging. In this work, we used many-body perturbation theory approaches, in particular the GW approximation with the Bethe-Salpeter equation (BSE) implemented in Gaussian basis sets, to calculate the quasiparticle properties and the absorption spectra of six cyclometalated Ir(III) complexes, going beyond TDDFT. In the presented results, we compared standard TDDFT simulations with BSE calculations performed on top of perturbative G0W0 and accounting for eigenvalue self-consistency. Moreover, in order to investigate in detail the effect of the DFT starting point, we concentrated on Ir(ppy)3 and performed GW-BSE simulations starting from different DFT exchange-correlation potentials.
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Affiliation(s)
- Marco Cazzaniga
- Consiglio Nazionale delle Ricerche , Istituto di Scienze e Tecnologie Chimiche (CNR-SCITEC) , 20133 Milano , Italy
| | - Fausto Cargnoni
- Consiglio Nazionale delle Ricerche , Istituto di Scienze e Tecnologie Chimiche (CNR-SCITEC) , 20133 Milano , Italy
| | - Marta Penconi
- Consiglio Nazionale delle Ricerche , Istituto di Scienze e Tecnologie Chimiche (CNR-SCITEC) , 20133 Milano , Italy
| | - Alberto Bossi
- Consiglio Nazionale delle Ricerche , Istituto di Scienze e Tecnologie Chimiche (CNR-SCITEC) , 20133 Milano , Italy
| | - Davide Ceresoli
- Consiglio Nazionale delle Ricerche , Istituto di Scienze e Tecnologie Chimiche (CNR-SCITEC) , 20133 Milano , Italy
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