1
|
Hruzd M, Durand R, Gauthier S, le Poul P, Robin-le Guen F, Achelle S. Photoluminescence of Platinum(II) Complexes with Diazine-Based Ligands. CHEM REC 2024; 24:e202300335. [PMID: 38847061 DOI: 10.1002/tcr.202300335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 03/18/2024] [Indexed: 06/27/2024]
Abstract
In the last past twenty years, research on luminescent platinum (II) complexes has been intensively developed for useful application such as organic light emitting diodes (OLEDs). More recently, new photoluminescent complexes based on diazine ligands (pyrimidine, pyrazine, pyridazine, quinazoline and quinoxaline) have been developed in this context. This review will summarize the photophysical properties of most of the phosphorescent diazine Pt(II) complexes described in the literature and compare the results to pyridine analogues whenever possible. Based on the emission color, and the photoluminescence quantum yield (PLQY) values, the relationship between structure modification, and photophysical properties are highlighted. Tuning of emission color, quantum yields in solution and solid state and, for some complexes, aggregation induced emission (AIE) or thermally activated delayed fluorescence (TADF) properties are described. When emitting OLEDs have been built from diazine Pt(II) complexes, the external quantum efficiency (EQE) values and luminance for different emission wavelengths and in some cases, chromaticity coordinates obtained from devices, are given. Finally, this review highlights the growing interest in studies of new luminescent diazine Pt(II) complexes for OLED applications.
Collapse
Affiliation(s)
- Mariia Hruzd
- Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes - UMR 6226, 5000, Rennes, France
| | - Raphaël Durand
- Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes - UMR 6226, 5000, Rennes, France
| | - Sébastien Gauthier
- Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes - UMR 6226, 5000, Rennes, France
| | - Pascal le Poul
- Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes - UMR 6226, 5000, Rennes, France
| | - Françoise Robin-le Guen
- Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes - UMR 6226, 5000, Rennes, France
| | - Sylvain Achelle
- Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes - UMR 6226, 5000, Rennes, France
| |
Collapse
|
2
|
Roy J, Forzatti M, Arnal L, Martín A, Fuertes S, Tordera D, Sicilia V. Pyrazolate-Bridged NHC Cyclometalated [Pt 2] Complexes and [Pt 2Ag(PPh 3)] + Clusters in Electroluminescent Devices. Inorg Chem 2024; 63:7275-7285. [PMID: 38587101 DOI: 10.1021/acs.inorgchem.4c00105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
The ionic transition metal complexes (iTMCs) [{Pt(C∧C*)(μ-Rpz)}2Ag(PPh3)]X (HC∧C* = 1-(4-(ethoxycarbonyl)phenyl)-3-methyl-1H-imidazole-2-ylidene, X = ClO4/PF6; Rpz = pz 1a/2a, 4-Mepz 1b/2b, and 3,5-dppz 1c/2c) were prepared from the neutral [{Pt(C∧C*)(μ-Rpz)}2] (Rpz = pz A, 4-Mepz B, and 3,5-dppz C) and fully characterized. The "Ag(PPh3)" fragment is in between the two square-planar platinum units in an "open book" disposition and bonded through two Pt-Ag donor-acceptor bonds, as shown by X-ray diffraction (dPt-Ag ∼ 2.78 Å, 1a-1c). 195Pt{1H} and 31P{1H} NMR confirmed that these solid-state structures remain in solution. Photoluminescence studies and theoretical calculations on 1a, were performed. The diphenylpyrazolate derivatives show the highest photoluminescence quantum yield (PLQY) in the solid state. Therefore, 2c and its neutral precursor C were selected as active materials on light-emitting devices. OLEDs fabricated with C showed a turn-on voltage of 3.2 V, a luminance peak of 21,357 cd m-2 at 13 V, and a peak current efficiency of 28.8 cd A-1 (9.5% EQE). They showed a lifetime t50 of 15.7 h. OLEDs using 2c showed a maximum luminance of 114 cd m-2, while LECs exhibited a maximum luminance of 20 cd m-2 and a current efficiency of around 0.2 cd A-1, with a t50 value of 50 min.
Collapse
Affiliation(s)
- Jorge Roy
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza 50009, Spain
| | - Michele Forzatti
- Instituto de Ciencia Molecular, Universidad de Valencia, C/Catedrático J. Beltran, 2, Paterna 46980, Spain
| | - Lorenzo Arnal
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza 50009, Spain
| | - Antonio Martín
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza 50009, Spain
| | - Sara Fuertes
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza 50009, Spain
| | - Daniel Tordera
- Instituto de Ciencia Molecular, Universidad de Valencia, C/Catedrático J. Beltran, 2, Paterna 46980, Spain
| | - Violeta Sicilia
- Departamento de Química Inorgánica, Escuela de Ingeniería y Arquitectura de Zaragoza, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Campus Río Ebro, Edificio Torres Quevedo, Zaragoza 50018, Spain
| |
Collapse
|
3
|
Yuan L, Yao H, Shen Y, Zhang Y. A cyclometalated Pt(II)-Pt(II) clamshell dimer with a triplet emission at 887 nm. Dalton Trans 2024; 53:5125-5132. [PMID: 38379520 DOI: 10.1039/d3dt04335e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Here, a cyclometalated Pt(II) clamshell dimer (complex 2) has been synthesized with the primary ligand of dibenzo(f,h)quinoxaline and an ancillary ligand of N,N'-diphenylformamidine. In addition, a mononuclear Pt(II) complex 1a and a binuclear Pt(II) complex 1b were also prepared. Complex 1a was coordinated by one cyclometalated ligand of dibenzo(f,h)quinoxaline, one chloride ion, and one N,N'-diphenylformamidine. Complex 1b was coordinated by one cyclometalated ligand of dibenzo(f,h)quinoxaline, two chloride ions, and two N,N'-diphenylformamidines. All of these three complexes were characterized by nuclear magnetic resonance (NMR) spectroscopy, high-resolution mass spectrometry (HRMS), elemental analyses, and single-crystal X-ray diffraction (XRD). The Pt-Pt distance in complex 2 was 2.8439(2) Å. It also exhibited a near-infrared (near-IR) emission at 887 nm in the pure solid state. On the other hand, complexes 1a and 1b exhibited triplet emission at 589 and 660 nm, respectively, in the pure solid state. Furthermore, in 2 wt% poly(Me methacrylate) (PMMA) films, complex 1a showed a triplet emission at 548 nm (with Φ = 84% and τ = 5.53 μs) and complex 1b showed an emission at 627 nm (with Φ = 79% and τ = 4.07 μs). Due to its great photophysical properties, complex 1b was deposited onto quartz plates for the detection of organic solvent vapors and it showed unique emission quenching for the vapor of tetrahydrofuran.
Collapse
Affiliation(s)
- Lequn Yuan
- Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commission, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, School of Chemistry and Chemical Engineering, Guangxi Minzu University, Nanning 530006, Guangxi, China.
| | - Haibo Yao
- Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commission, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, School of Chemistry and Chemical Engineering, Guangxi Minzu University, Nanning 530006, Guangxi, China.
- Engineering Research Center for Industrial Wastewater Treatment and Reuse of Shandong Province, School of Chemical Engineering and Safety, Binzhou University, Binzhou 256603, Shandong, China
| | - Yunjun Shen
- Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commission, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, School of Chemistry and Chemical Engineering, Guangxi Minzu University, Nanning 530006, Guangxi, China.
| | - Yuzhen Zhang
- Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commission, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, School of Chemistry and Chemical Engineering, Guangxi Minzu University, Nanning 530006, Guangxi, China.
| |
Collapse
|
4
|
Gómez de Segura D, Corral-Zorzano A, Alcolea E, Moreno MT, Lalinde E. Phenylbenzothiazole-Based Platinum(II) and Diplatinum(II) and (III) Complexes with Pyrazolate Groups: Optical Properties and Photocatalysis. Inorg Chem 2024; 63:1589-1606. [PMID: 38247362 PMCID: PMC10806813 DOI: 10.1021/acs.inorgchem.3c03532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/21/2023] [Accepted: 12/22/2023] [Indexed: 01/23/2024]
Abstract
Based on 2-phenylbenzothiazole (pbt) and 2-(4-dimethylaminophenyl)benzothiazole (Me2N-pbt), mononuclear [Pt(pbt)(R'2-pzH)2]PF6 (R'2-pzH = pzH 1a, 3,5-Me2pzH 1b, 3,5-iPr2pzH 1c) and diplatinum (PtII-PtII) [Pt(pbt)(μ-R'2pz)]2 (R'2-pz = pz 2a, 3,5-Me2pz 2b, 3,5-iPr2pz 2c) and [Pt(Me2N-pbt)(μ-pz)]2 (3a) complexes have been prepared. In the presence of sunlight, 2a and 3a evolve, in CHCl3 solution, to form the PtIII-PtIII complexes [Pt(R-pbt)(μ-pz)Cl]2 (R = H 4a, NMe2 5a). Experimental and computational studies reveal the negligible influence of the pyrazole or pyrazolate ligands on the optical properties of 1a-c and 2a,b, which exhibit a typical 3IL/3MLCT emission, whereas in 2c the emission has some 3MMLCT contribution. 3a displays unusual dual, fluorescence (1ILCT or 1MLCT/1LC), and phosphorescence (3ILCT) emissions depending on the excitation wavelength. The phosphorescence is lost in aerated solutions due to sensitization of 3O2 and formation of 1O2, whose determined quantum yield is also wavelength dependent. The phosphorescence can be reversibly photoinduced (365 nm, ∼ 15 min) in oxygenated THF and DMSO solutions. In 4a and 5a, the lowest electronic transitions (S1-S3) have mixed characters (LMMCT/LXCT/L'XCT 4a and LMMCT/LXCT/ILCT 5a) and they are weakly emissive in rigid media. The 1O2 generation property of complex 3a is successfully used for the photooxidation of p-bromothioanisol showing its potential application toward photocatalysis.
Collapse
Affiliation(s)
- David Gómez de Segura
- Departamento de Química, Instituto
de Investigación en Química (IQUR), Complejo Científico
Tecnológico, Universidad de La Rioja, Madre de Dios 53, Logroño 26006, Spain
| | - Andrea Corral-Zorzano
- Departamento de Química, Instituto
de Investigación en Química (IQUR), Complejo Científico
Tecnológico, Universidad de La Rioja, Madre de Dios 53, Logroño 26006, Spain
| | - Eduardo Alcolea
- Departamento de Química, Instituto
de Investigación en Química (IQUR), Complejo Científico
Tecnológico, Universidad de La Rioja, Madre de Dios 53, Logroño 26006, Spain
| | - M. Teresa Moreno
- Departamento de Química, Instituto
de Investigación en Química (IQUR), Complejo Científico
Tecnológico, Universidad de La Rioja, Madre de Dios 53, Logroño 26006, Spain
| | - Elena Lalinde
- Departamento de Química, Instituto
de Investigación en Química (IQUR), Complejo Científico
Tecnológico, Universidad de La Rioja, Madre de Dios 53, Logroño 26006, Spain
| |
Collapse
|
5
|
Shafikov MZ, Zaytsev AV, Kozhevnikov VN. Trinuclear Cyclometalated Iridium(III) Complex Exhibiting Intense Phosphorescence of an Unprecedented Rate. Inorg Chem 2024; 63:1317-1327. [PMID: 38154085 DOI: 10.1021/acs.inorgchem.3c03810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2023]
Abstract
Herein, we present two novel cyclometalated Ir(III) complexes of dinuclear and trinuclear design, Ir2(dppm)3(acac)2 and Ir3(dppm)4(acac)3, respectively, where dppm is 4,6-di(4-tert-butylphenyl)pyrimidine ligand and acac is acetylacetonate ligand. In both cases, rac-diastereomers were isolated during the synthesis. The materials show intense phosphorescence of outstanding rates (kr = ΦPL/τ) with corresponding radiative decay times of only τr = 1/kr = 0.36 μs for dinuclear Ir2(dppm)3(acac)2 and still shorter τr = 0.30 μs for trinuclear Ir3(dppm)4(acac)3, as measured for doped polystyrene film samples under ambient temperature. Measured under cryogenic conditions, radiative decay times of the three T1 substates (I, III, and III) and substate energy separations are τI = 11.8 μs, τII = 7.1 μs, τIII = 0.06 μs, ΔE(II-I) = 7 cm-1, and ΔE(III-I) = 175 cm-1 for dinuclear Ir2(dppm)3(acac)2 and τI = 3.1 μs, τII = 3.5 μs, τIII = 0.03 μs, ΔE(II-I) ≈ 1 cm-1, and ΔE(III-I) = 180 cm-1 for trinuclear Ir3(dppm)4(acac)3. The determined T1 state ZFS values (ΔE(III-I)) are smaller compared to that of mononuclear analogue Ir(dppm)2(acac) (ZFS = 210-1 cm). Theoretical analysis suggests that the high phosphorescence rates in multinuclear materials can be associated with the increased number of singlet states lending oscillator strength to the T1 → S0 transition.
Collapse
Affiliation(s)
- Marsel Z Shafikov
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstrasse 31, Regensburg D-93053, Germany
| | - Andrey V Zaytsev
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, U.K
| | - Valery N Kozhevnikov
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, U.K
| |
Collapse
|
6
|
Gupta R, Sahni P, Jana SK, Negi A, Pal AK. Effect of substitution on deep-blue Ir(III) N-heterocyclic carbene (NHC) emitters. Dalton Trans 2023; 52:15597-15607. [PMID: 37840343 DOI: 10.1039/d3dt01947k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
The development of Ir(III)-NHC phosphors that display deep-blue luminescence without sacrificing the high photoluminescence quantum yield (PLQY) has become a pivotal area of research. In this respect, two novel deep-blue Ir-NHC emitters (C1 and C2) with strategically designed pro-carbenic imidazolium ligands (L1 and L2) incorporating a heavy bromine atom at the ligand-scaffold were synthesized in good yields (∼80% for L1, L2 and 65% for C1, C2). The ground and excited state properties of the complexes were photophysically determined and the results were found to be in accordance with theoretical calculations at the DFT and TD-DFT levels. Due to the strong σ-donation of the carbene ligands, complexes C1 and C2 displayed oxidation at low anodic potentials. Both the complexes showed deep-blue emission either in solution (λem ∼ 400-425 nm) or as PMMA-doped films of varying concentrations (λem ∼ 400 nm) with an ∼15 times enhanced PLQY with respect to benchmark Ir-NHC complexes. The strategy of incorporating the heavy bromine atom to reduce the molecular vibrations in C1 and C2 was further supported by ∼250 times reduced non-radiative decay constants (knr) and Huang-Rhys constants of C1 and C2 in comparison to those of the benchmark complexes. These facts were also supported by triplet frequency calculations of C1 and C2 to identify the absence of vibrations.
Collapse
Affiliation(s)
- Rahat Gupta
- Department of Chemistry, Indian Institute of Technology Jammu, Nagrota Bypass Road, Jammu and Kashmir-181221, India.
| | - Priya Sahni
- Department of Chemistry, Indian Institute of Technology Jammu, Nagrota Bypass Road, Jammu and Kashmir-181221, India.
| | - Salil K Jana
- Department of Chemistry, Indian Institute of Technology Jammu, Nagrota Bypass Road, Jammu and Kashmir-181221, India.
| | - Anshul Negi
- Department of Chemistry, Indian Institute of Technology Jammu, Nagrota Bypass Road, Jammu and Kashmir-181221, India.
| | - Amlan K Pal
- Department of Chemistry, Indian Institute of Technology Jammu, Nagrota Bypass Road, Jammu and Kashmir-181221, India.
| |
Collapse
|
7
|
Sun Y, Zhan F, Huang D, Wang X, Dou L, Xu K, Yang YF, Li G, She Y. 8-Phenylquinoline-Based Tetradentate 6/6/6 Platinum(II) Complexes for Near-Infrared Emitters. Inorg Chem 2023; 62:13156-13164. [PMID: 37531143 DOI: 10.1021/acs.inorgchem.3c02356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
A series of novel tetradentate 6/6/6 Pt(II) complexes containing an 8-phenylquinoline-benzo[d]imidazole-carbazole ligand was designed; the Pt(II) complexes could be synthesized by metalizing the corresponding ligand with K2PtCl4 in high isolated yields of 60-90%. Experimental and theoretical studies suggested that the ligand modification of the quinoline moieties of the Pt(II) complexes could tune their electrochemical, photophysical, and excited-state properties. Notably, all the Pt(II) complexes exhibited highly electrochemical stabilities with reversible redox processes except the quasi-reversible reduction of PtYL3. The large π-conjugation of the ligand together with increased metal-to-ligand charge-transfer (3MLCT) characters in T1 states enabled the Pt(II) complexes to show broad Gaussian-type NIR emission spectra with high photoluminescence quantum efficiencies of 1.2-1.5% and short τ of 0.8-1.5 μs in dichloromethane at room temperature. This work should provide a valuable reference for the design and development of monomer NIR emitters.
Collapse
Affiliation(s)
- Yulu Sun
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Feng Zhan
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Disheng Huang
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Xia Wang
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Lijie Dou
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Kewei Xu
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Yun-Fang Yang
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Guijie Li
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Yuanbin She
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| |
Collapse
|
8
|
Salthouse R, Sil A, Gildea LF, Yufit DS, Williams JAG. Platinum(II) Complexes of Nonsymmetrical NCN-Coordinating Ligands: Unimolecular and Excimeric Luminescence Properties and Comparison with Symmetrical Analogues. Inorg Chem 2023; 62:12356-12371. [PMID: 37498694 PMCID: PMC10410614 DOI: 10.1021/acs.inorgchem.3c01439] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Indexed: 07/29/2023]
Abstract
A series of seven new platinum(II) complexes PtLnCl have been prepared, where Ln is an NCN-coordinating ligand comprising a benzene ring 1,3-disubstituted with two different azaheterocycles. In PtL1-5Cl, one heterocycle is a simple pyridine ring, while the other is an isoquinoline, a quinoline, a pyrimidine (L1, L2, L3), or a p-CF3- or p-OMe-substituted pyridine (L4 and L5). PtL6Cl incorporates both a p-CF3 and a p-OMe-substituted pyridine. The synthesis of the requisite proligands HLn is achieved using Pd-catalyzed cross-coupling methodology. The molecular structures of six of the Pt(II) complexes have been determined by X-ray diffraction. All the complexes are brightly luminescent in deoxygenated solution at room temperature. The absorption and emission properties are compared with those of the corresponding symmetrical complexes featuring two identical heterocycles, PtLnsymCl, and of the parent Pt(dpyb)Cl containing two unsubstituted pyridines [dpybH = 1,3-di(2-pyridyl)benzene]. While the absorption spectra of the nonsymmetrical complexes show features of both PtLnsymCl and Pt(dpyb)Cl, the emission generally resembles that of whichever of the corresponding symmetrical complexes has the lower-energy emission. PtL1Cl differs in that─at room temperature but not at 77 K─it displays emission bands that can be attributed to excited states involving both the pyridine and the isoquinoline rings, despite the latter being unequivocally lower in energy. This unusual behavior is attributed to thermally activated repopulation of the former excited state from the latter, facilitated by the very long-lived nature of the isoquinoline-based excited state. At elevated concentrations, all the complexes show an additional red-shifted emission band attributable to excimers. For PtL1Cl, the excimer strikingly dominates the emission spectra at all but the lowest concentrations (<10-5 M). Trends in the energies of the excimers and their propensity to form are compared with those of the symmetrical analogues.
Collapse
Affiliation(s)
| | - Amit Sil
- Department of Chemistry, Durham
University, South Road, Durham DH1
3LE, U.K.
| | - Louise F. Gildea
- Department of Chemistry, Durham
University, South Road, Durham DH1
3LE, U.K.
| | - Dmitry S. Yufit
- Department of Chemistry, Durham
University, South Road, Durham DH1
3LE, U.K.
| | | |
Collapse
|
9
|
Hruzd M, Kahlal S, le Poul N, Wojcik L, Cordier M, Saillard JY, Rodríguez-López J, Robin-le Guen F, Gauthier S, Achelle S. Phosphorescent cyclometalated platinum(II) complexes with phenyldiazine N^C ligands. Dalton Trans 2023; 52:1927-1938. [PMID: 36722926 DOI: 10.1039/d2dt03690h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A series of phosphorescent platinum(II) complexes containing various phenyldiazine-type bidentate N^C ligands have been successfully synthesized and characterized. Structural modifications have been made to bidentate cyclometalating ligands regarding the nature of the diazine ring (pyrimidine, pyrazine and quinazoline), the substituent groups at the C4 position of the pyrimidine ring (OCH3, CF3) and the EDGs at the para position of the Pt atom (OCH3, Ph, NPh2, carbazol). In addition, the electronic properties of the azaheterocyclic ancillary ligand have been modulated in this series of complexes (pyridine, 4-methoxy-pyridine or pyrimidine). X-ray diffraction studies have been performed on three complexes, revealing Pt(II) ions in a distorted square-planar geometrical environment with no Pt(II)⋯Pt(II) interactions but with moderate π-π interactions in the solid-state structure. Electrochemical and computational studies suggest a ligand-centered reduction on the diazine ligands with, in some cases, additional contribution from the azaheterocyclic ancillary ligand, whereas oxidation occurs on the Pt-phenyl ring substituent moieties. All complexes exhibit phosphorescence emission ranging from green to red/near-infrared, both in solution and in the solid state. Complexes bearing a 2-(3-methoxyphenyl)pyrimidine ligand show the best PLQY of the series, up to 52% in a CH2Cl2 solution and 20% in the solid state. Furthermore, the solid state PLQY of one of the near-infrared emitting phenylquinazoline complex has been found to be 6%.
Collapse
Affiliation(s)
- Mariia Hruzd
- Univ. Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35000 Rennes, France.
| | - Samia Kahlal
- Univ. Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35000 Rennes, France.
| | - Nicolas le Poul
- Université de Bretagne Occidentale, Laboratoire de Chimie, Electrochimie Moléculaires et Chimie Analytique, UMR CNRS 6521, UFR Science et Techniques, 6 Avenue Victor le Gorgeu, CS 93837, Brest Cedex 3, France
| | - Laurianne Wojcik
- Université de Bretagne Occidentale, Laboratoire de Chimie, Electrochimie Moléculaires et Chimie Analytique, UMR CNRS 6521, UFR Science et Techniques, 6 Avenue Victor le Gorgeu, CS 93837, Brest Cedex 3, France
| | - Marie Cordier
- Univ. Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35000 Rennes, France.
| | - Jean-Yves Saillard
- Univ. Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35000 Rennes, France.
| | - Julián Rodríguez-López
- Universidad de Castilla-La Mancha, Área de Química Orgánica, Facultad de Ciencias y Tecnologías Químicas, Avda. Camilo José Cela 10, 13071, Ciudad Real, Spain
| | - Françoise Robin-le Guen
- Univ. Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35000 Rennes, France.
| | - Sébastien Gauthier
- Univ. Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35000 Rennes, France.
| | - Sylvain Achelle
- Univ. Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35000 Rennes, France.
| |
Collapse
|
10
|
Salthouse RJ, Pander P, Yufit DS, Dias FB, Williams JAG. Near-infrared electroluminescence beyond 940 nm in Pt(N^C^N)X complexes: influencing aggregation with the ancillary ligand X. Chem Sci 2022; 13:13600-13610. [PMID: 36507161 PMCID: PMC9682897 DOI: 10.1039/d2sc05023d] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/24/2022] [Indexed: 11/13/2022] Open
Abstract
We present a study of aggregate excited states formed by complexes of the type Pt(N^C^N)X, where N^C^N represents a tridentate cyclometallating ligand, and X = SCN or I. These materials display near-infrared (NIR) photoluminescence in film and electroluminescence in NIR OLEDs with λ max EL = 720-944 nm. We demonstrate that the use of X = SCN or I modulates aggregate formation compared to the parent complexes where X = Cl. While the identity of the monodentate ligand affects the energy of Pt-Pt excimers in solution in only a subtle way, it strongly influences aggregation in film. Detailed calculations on aggregates of different sizes support the experimental conclusions from steady-state and time-resolved luminescence studies at variable temperatures. The use of X = I appears to limit aggregation to the formation of dimers, while X = SCN promotes the formation of larger aggregates, such as tetramers and pentamers, leading in turn to NIR photo- and electroluminescence > 850 nm. A possible explanation for the contrasting influence of the monodentate ligands is the lesser steric hindrance associated with the SCN group compared to the bulkier I ligand. By exploiting the propensity of the SCN complexes to form extended aggregates, we have prepared an NIR-emitting OLED that shows very long wavelength electroluminescence, with λ max EL = 944 nm and a maximum EQE = 0.3 ± 0.1%. Such data appear to be unprecedented for a device relying on a Pt(ii) complex aggregate as the emitter.
Collapse
Affiliation(s)
| | - Piotr Pander
- Faculty of Chemistry, Silesian University of Technology M. Strzody 9 Gliwice 44-100 Poland
- Department of Physics, Durham University South Road Durham DH1 3LE UK
| | - Dmitry S Yufit
- Department of Chemistry, Durham University South Road Durham DH1 3LE UK
| | - Fernando B Dias
- Department of Physics, Durham University South Road Durham DH1 3LE UK
| | | |
Collapse
|
11
|
Shen Y, Kong X, Yang F, Bian HD, Cheng G, Cook TR, Zhang Y. Deep Blue Phosphorescence from Platinum Complexes Featuring Cyclometalated N-Pyridyl Carbazole Ligands with Monocarborane Clusters (CB 11H 12-). Inorg Chem 2022; 61:16707-16717. [PMID: 36205461 DOI: 10.1021/acs.inorgchem.2c02467] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The utilization of deep blue phosphorescent materials in high-performance displays and solid-state lighting requires high quantum efficiencies and color purities. Here, we describe the preparation and luminescent properties of novel platinum triplet emitters featuring cyclometalated N-pyridyl-carbazole ligands functionalized with closo-monocarborane clusters [CB11H12]-. All reported complexes were fully characterized by using standard small molecule techniques (UV-vis, cyclic voltammetry, nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HRMS)), and their solid-state structures were elucidated by X-ray diffraction. These platinum phosphors emit in the blue region of the visible wavelength spectrum in both the solid and solution states. Complex 4a exhibits the highest luminous efficiency at λem = 439 nm with a photoluminescent quantum yield (PLQY) of 60% by dispersing in a PMMA matrix. Electrochemical and computational studies of complexes 4a and 4b revealed that the blue phosphorescence originates mainly from intraligand 3π → π* (3ILCT) transitions with relatively small 3MLCT mixing. A deep-blue OLED containing 4a as the light-emitting dopant was successfully fabricated using a solution-processed method, and the device exhibited blue photoluminescence with CIE coordinates of (0.17, 0.15) and a maximum external quantum efficiency (EQEmax) value of 6.2%. This article represents the pioneering study of a deep blue PhOLED using a Pt complex bearing a closo-monocarborane anion substituent, providing a new avenue into the preparation of novel triplet emitters based on boron-rich cluster anions.
Collapse
Affiliation(s)
- Yunjun Shen
- Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commission, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, School of Chemistry and Chemical Engineering, Guangxi Minzu University, No. 158, Daxue West Road, Nanning, Guangxi 530006, China
| | - Xiangjun Kong
- Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commission, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, School of Chemistry and Chemical Engineering, Guangxi Minzu University, No. 158, Daxue West Road, Nanning, Guangxi 530006, China
| | - Fengjie Yang
- Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commission, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, School of Chemistry and Chemical Engineering, Guangxi Minzu University, No. 158, Daxue West Road, Nanning, Guangxi 530006, China
| | - He-Dong Bian
- Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commission, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, School of Chemistry and Chemical Engineering, Guangxi Minzu University, No. 158, Daxue West Road, Nanning, Guangxi 530006, China
| | - Gang Cheng
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Timothy R Cook
- Department of Chemistry, University at Buffalo, The State University of New York, 856 Natural Sciences Complex, Buffalo, New York 14260, United States
| | - Yuzhen Zhang
- Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commission, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, School of Chemistry and Chemical Engineering, Guangxi Minzu University, No. 158, Daxue West Road, Nanning, Guangxi 530006, China
| |
Collapse
|
12
|
Roy R, Khan A, Dutta T, Koner AL. Red to NIR-emissive anthracene-conjugated PMI dyes with dual functions: singlet-oxygen response and lipid-droplet imaging. J Mater Chem B 2022; 10:5352-5363. [PMID: 35583595 DOI: 10.1039/d2tb00349j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The rich chemistry of solution-processable red and near-infrared (NIR) organic emitters has emerged as an attractive and progressive research field because of their particular applications in organic optoelectronics and bioimaging. Also, one can see that the research area of perylene monoimide-based red and NIR-emissive fluorophores is underexplored, which prompted us to design and synthesize three anthracene-conjugated PMI dyes exhibiting strong emission in the red and NIR window in solution. Three PMI-based fluorophores were synthesized via conjoining anthracene and donor moieties (-Ph, -N,N-PhNMe2) with a PMI core via an acetylene linkage at the peri-position, which helped to attain extensive electronic conjugation, which was reflected in red and NIR-emission in solution. The key molecular features to be highlighted here are: all three dyes are strongly emissive in solution, as unveiled by the excellent absolute fluorescence QYs; and they possess tuneable emission properties, guided by the donor strength and a profound Stokes shift (100-200 nm). The three fluorescent dyes demonstrated appreciable singlet-oxygen (1O2) sensitivity when photoirradiated with methylene blue (MB) in solution, showing a substantial blue-shift in emission in a ratiometric manner. Further, the treatment of dye-MB solution with α-tocopherol (1O2 scavenger) validated the presence of 1O2 as the only oxidizing species generated by MB in solution. Computational investigations gave insight into the twisting of donor moieties in their ground-state optimized geometries, the modulation of the FMO energy gap, and the thermodynamic feasibility of the 1O2 reaction. Finally, via taking advantage of the red and NIR-emission, we successfully utilized one of the fluorophores as a lipid-droplet marker for bioimaging in HepG2 cells.
Collapse
Affiliation(s)
- Rupam Roy
- Bionanotechnology Laboratory, Department of Chemistry Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh, India.
| | - Aasif Khan
- Bionanotechnology Laboratory, Department of Chemistry Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh, India.
| | - Tanoy Dutta
- Bionanotechnology Laboratory, Department of Chemistry Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh, India.
| | - Apurba Lal Koner
- Bionanotechnology Laboratory, Department of Chemistry Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh, India.
| |
Collapse
|
13
|
Coffey B, Clough L, Bartkus DD, McClellan IC, Greenberg MW, LaFratta CN, Tanski JM, Anderson CM. Photophysical Properties of Cyclometalated Platinum(II) Diphosphine Compounds in the Solid State and in PMMA Films. ACS OMEGA 2021; 6:28316-28325. [PMID: 34723028 PMCID: PMC8552474 DOI: 10.1021/acsomega.1c04509] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 10/04/2021] [Indexed: 05/06/2023]
Abstract
Platinum(II) compounds were synthesized with both chelate cyclometalated ligands and chelate diphosphine ligands. The cyclometalated ligands include phenylpyridine and a benzothiophene-containing ligand. The three new benzothiophene compounds were characterized by nuclear magnetic resonance (NMR) spectroscopy, high-resolution mass spectrometry (HR-MS), and photophysical measurements. In the case of one compound, L1-DPPM, the structure was determined by single crystal X-ray diffraction. The structural coherence of the noncrystalline emissive solid state was measured by X-ray total scattering real space pair distribution function analysis. Quantum yield values of all of the platinum compounds measured in the solid state and in PMMA films were much greater than in solution.
Collapse
Affiliation(s)
- Belle Coffey
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road, Annandale-on-Hudson, New York 12504, United States
| | - Lily Clough
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road, Annandale-on-Hudson, New York 12504, United States
| | - Daphne D. Bartkus
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road, Annandale-on-Hudson, New York 12504, United States
| | - Ian C. McClellan
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road, Annandale-on-Hudson, New York 12504, United States
| | - Matthew W. Greenberg
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road, Annandale-on-Hudson, New York 12504, United States
| | - Christopher N. LaFratta
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road, Annandale-on-Hudson, New York 12504, United States
| | - Joseph M. Tanski
- Department
of Chemistry, Vassar College, Poughkeepsie, New York 12604, United States
| | - Craig M. Anderson
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road, Annandale-on-Hudson, New York 12504, United States
| |
Collapse
|
14
|
Sun Y, Liu B, Guo Y, Chen X, Lee YT, Feng Z, Adachi C, Zhou G, Chen Z, Yang X. Developing Efficient Dinuclear Pt(II) Complexes Based on the Triphenylamine Core for High-Efficiency Solution-Processed OLEDs. ACS APPLIED MATERIALS & INTERFACES 2021; 13:36020-36032. [PMID: 34283914 DOI: 10.1021/acsami.1c06148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The various applications of dinuclear complexes have attracted increasing attention. However, the electroluminescence efficiencies of dinuclear Pt(II) complexes are far from satisfactory. Herein, based on the triphenylamine core, we develop four dinuclear Pt(II) complexes that cover the emission colors from yellow to red with high photoluminescence quantum efficiencies of up to 0.79 in doped films. The solid-state structure of PyDPt is revealed by the single-crystal X-ray diffraction investigation. Besides, solution-processed OLEDs have been fabricated with different electron transport materials. With higher electron mobility and excellent hole-blocking ability, 1,3,5-tri(m-pyridin-3-ylphenyl)benzene (TmPyPB) can help to realize good charge balance in related OLEDs. In addition, angle-dependent PL spectra reveal the preferentially horizontal orientation of these dinuclear Pt(II) complexes in doped CBP films, which benefits the outcoupling efficiencies. Therefore, the yellow OLED based on PyDPt shows unexpected high performance with a peak current efficiency of up to 78.7 cd/A and an external quantum efficiency of up to 22.4%, which is the highest EQE reported for OLEDs based on dinuclear Pt(II) complexes so far. This study demonstrates the great potential of developing dinuclear Pt(II) complexes for achieving excellent electroluminescence efficiencies.
Collapse
Affiliation(s)
- Yuanhui Sun
- School of Chemistry, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Key Laboratory of Sustainable Energy Material Chemistry, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - Bochen Liu
- School of Applied Physics and Materials, Wuyi University, Jiangmen 529020, P. R. China
| | - Yue Guo
- School of Applied Physics and Materials, Wuyi University, Jiangmen 529020, P. R. China
| | - Xi Chen
- School of Chemistry, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Key Laboratory of Sustainable Energy Material Chemistry, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - Yi-Ting Lee
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Zhao Feng
- School of Chemistry, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Key Laboratory of Sustainable Energy Material Chemistry, Xi'an Jiaotong University, Xi'an 710049, P. R. China
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Guijiang Zhou
- School of Chemistry, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Key Laboratory of Sustainable Energy Material Chemistry, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - Zhao Chen
- School of Applied Physics and Materials, Wuyi University, Jiangmen 529020, P. R. China
| | - Xiaolong Yang
- School of Chemistry, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Key Laboratory of Sustainable Energy Material Chemistry, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| |
Collapse
|
15
|
Mauro M. Phosphorescent multinuclear complexes for optoelectronics: tuning of the excited-state dynamics. Chem Commun (Camb) 2021; 57:5857-5870. [PMID: 34075949 DOI: 10.1039/d1cc01077h] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Luminescent transition metal complexes have attracted a great deal of attention in the last two decades from both fundamental and application points of view. The majority of the investigated and most efficient systems consist of monometallic compounds with judiciously selected ligand sphere, providing excellent triplet emitters for both lab-scale and real-market light-emitting devices for display technologies. More recently, chemical architectures comprising multimetallic compounds have appeared as an emerging and valuable alternative. Herein, the most recent trends in the field are showcased in a systematic approach, where the different examples are classified by metal center and ligand(s) scaffold. Their optical and electroluminescence properties are presented and compared as well. Indeed, the multimetallic strategy has proven to be highly suitable for compounds emitting efficiently in the challenging red to near-infrared region, yielding metal-based emitters with improved optical properties in terms of enhanced emission efficiency, shortened excited-state lifetime, and faster radiative rate constant. Finally, the advantages and drawbacks of the multimetallic approach will be discussed.
Collapse
Affiliation(s)
- Matteo Mauro
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), UMR7504 Université de Strasbourg & CNRS 23 rue du Loess, 67083 Strasbourg, France.
| |
Collapse
|
16
|
Herrero ACG, Féron M, Bendiab N, Den Hertog M, Reita V, Salut R, Palmino F, Coraux J, Chérioux F. Nano-sheets of two-dimensional polymers with dinuclear (arene)ruthenium nodes, synthesised at a liquid/liquid interface. NANOTECHNOLOGY 2021; 32:355603. [PMID: 34030148 DOI: 10.1088/1361-6528/ac0472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/24/2021] [Indexed: 06/12/2023]
Abstract
We developed a new class of mono- or few-layered two-dimensional polymers based on dinuclear (arene)ruthenium nodes, obtained by combining the imine condensation with an interfacial chemistry process, and use a modified Langmuir-Schaefer method to transfer them onto solid surfaces. Robust nano-sheets of two-dimensional polymers including dinuclear complexes of heavy ruthenium atoms as nodes were synthesised. These nano-sheets, whose thickness is of a few tens of nanometers, were suspended onto solid porous membranes. Then, they were thoroughly characterised with a combination of local probes, including Raman spectroscopy, Fourier transform infrared spectroscopy and transmission electron microscopy in imaging and diffraction mode.
Collapse
Affiliation(s)
| | - Michel Féron
- University Bourgogne Franche-Comté, FEMTO-ST, UFC, CNRS, 15B avenue des Montboucons, F-25030 Besançon Cedex, France
| | - Nedjma Bendiab
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut NÉEL, F-38000 Grenoble, France
| | - Martien Den Hertog
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut NÉEL, F-38000 Grenoble, France
| | - Valérie Reita
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut NÉEL, F-38000 Grenoble, France
| | - Roland Salut
- University Bourgogne Franche-Comté, FEMTO-ST, UFC, CNRS, 15B avenue des Montboucons, F-25030 Besançon Cedex, France
| | - Frank Palmino
- University Bourgogne Franche-Comté, FEMTO-ST, UFC, CNRS, 15B avenue des Montboucons, F-25030 Besançon Cedex, France
| | - Johann Coraux
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut NÉEL, F-38000 Grenoble, France
| | - Frédéric Chérioux
- University Bourgogne Franche-Comté, FEMTO-ST, UFC, CNRS, 15B avenue des Montboucons, F-25030 Besançon Cedex, France
| |
Collapse
|
17
|
Pander P, Daniels R, Zaytsev AV, Horn A, Sil A, Penfold TJ, Williams JAG, Kozhevnikov VN, Dias FB. Exceptionally fast radiative decay of a dinuclear platinum complex through thermally activated delayed fluorescence. Chem Sci 2021; 12:6172-6180. [PMID: 33996015 PMCID: PMC8098751 DOI: 10.1039/d1sc00160d] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 03/19/2021] [Indexed: 12/13/2022] Open
Abstract
A novel dinuclear platinum(ii) complex featuring a ditopic, bis-tetradentate ligand has been prepared. The ligand offers each metal ion a planar O^N^C^N coordination environment, with the two metal ions bound to the nitrogen atoms of a bridging pyrimidine unit. The complex is brightly luminescent in the red region of the spectrum with a photoluminescence quantum yield of 83% in deoxygenated methylcyclohexane solution at ambient temperature, and shows a remarkably short excited state lifetime of 2.1 μs. These properties are the result of an unusually high radiative rate constant of around 4 × 105 s-1, a value which is comparable to that of the very best performing Ir(iii) complexes. This unusual behaviour is the result of efficient thermally activated reverse intersystem crossing, promoted by a small singlet-triplet energy difference of only 69 ± 3 meV. The complex was incorporated into solution-processed OLEDs achieving EQEmax = 7.4%. We believe this to be the first fully evidenced report of a Pt(ii) complex showing thermally activated delayed fluorescence (TADF) at room temperature, and indeed of a Pt(ii)-based delayed fluorescence emitter to be incorporated into an OLED.
Collapse
Affiliation(s)
- Piotr Pander
- Department of Physics, Durham University South Road Durham DH1 3LE UK
| | - Ruth Daniels
- Department of Applied Sciences, Northumbria University Ellison Building Newcastle upon Tyne NE1 8ST UK
| | - Andrey V Zaytsev
- Department of Applied Sciences, Northumbria University Ellison Building Newcastle upon Tyne NE1 8ST UK
| | - Ashleigh Horn
- Department of Applied Sciences, Northumbria University Ellison Building Newcastle upon Tyne NE1 8ST UK
| | - Amit Sil
- Department of Chemistry, Durham University South Road Durham DH1 3LE UK
| | - Thomas J Penfold
- Chemistry - School of Natural and Environmental Sciences, Newcastle University Newcastle upon Tyne NE1 7RU UK
| | | | - Valery N Kozhevnikov
- Department of Applied Sciences, Northumbria University Ellison Building Newcastle upon Tyne NE1 8ST UK
| | - Fernando B Dias
- Department of Physics, Durham University South Road Durham DH1 3LE UK
| |
Collapse
|
18
|
|
19
|
Shafikov MZ, Martinscroft R, Hodgson C, Hayer A, Auch A, Kozhevnikov VN. Non-Stereogenic Dinuclear Ir(III) Complex with a Molecular Rack Design to Afford Efficient Thermally Enhanced Red Emission. Inorg Chem 2021; 60:1780-1789. [DOI: 10.1021/acs.inorgchem.0c03251] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marsel Z. Shafikov
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstrasse 31, Regensburg 93053, Germany
- Ural Federal University, Mira 19, Ekaterinburg 620002, Russia
| | - Ross Martinscroft
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, United Kingdom
| | - Craig Hodgson
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, United Kingdom
| | - Anna Hayer
- Merck KGaA, Frankfurter Str. 250, 64293 Darmstadt, Germany
| | - Armin Auch
- Merck KGaA, Frankfurter Str. 250, 64293 Darmstadt, Germany
| | - Valery N. Kozhevnikov
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, United Kingdom
| |
Collapse
|
20
|
Shafikov MZ, Zaytsev AV, Kozhevnikov VN. Halide-Enhanced Spin-Orbit Coupling and the Phosphorescence Rate in Ir(III) Complexes. Inorg Chem 2021; 60:642-650. [PMID: 33405901 DOI: 10.1021/acs.inorgchem.0c02469] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The spin-forbidden nature of phosphorescence in Ir(III) complexes is relaxed by the metal-induced effect of spin-orbit coupling (SOC). A further increase of the phosphorescence rate could potentially be achieved by introducing additional centers capable of further enhancing the SOC effect, such as metal-coordinated halides. Herein, we present a dinuclear Ir(III) complex Ir2I2 that contains two Ir(III)-iodide moieties. The complex shows intense phosphorescence with a quantum yield of ΦPL(300 K) = 90% and a submicrosecond decay time of only τ(300 K) = 0.34 μs, as measured under ambient temperature for the degassed toluene solution. These values correspond to a top value T1 → S0 phosphorescence rate of kr = 2.65 × 106 s-1. Investigations at cryogenic temperatures allowed us to determine the zero-field splitting (ZFS) of the emitting state T1 ZFS(III-I) = 170 cm-1 and unusually short individual decay times of T1 substates: τ(I) = 6.4 μs, τ(II) = 7.6 μs, and τ(III) = 0.05 μs. This indicates a strong SOC of state T1 with singlet states. Theoretical investigations suggest that the SOC of state T1 with singlets is also contributed by halides. Strongly contributing to the higher occupied molecular orbitals of the complex (e.g., HOMO, HOMO - 1, and so forth), iodides work as important SOC centers that operate in tandem with metals. The examples of Ir2I2 and of earlier reported analogous complex Ir2Cl2 reveal that the metal-coordinated halides can enhance the SOC of state T1 with singlets and, consequently, the phosphorescence rate. A comparative study of Ir2I2 and Ir2Cl2 shows that the share of halides in total contribution (halides plus metals) to the SOC of state T1 with singlets increases strongly upon exchange of chlorides for iodides. The exchange also led to the decrease in values of ZFS of the T1 state from ZFS(III-I) = 205 cm-1 for Ir2Cl2 to T1 ZFS(III-I) = 170 cm-1 for Ir2I2. This results in a more efficient thermal population of the fastest emitting T1 substate III, thus further enhancing the room-temperature phosphorescence rate.
Collapse
Affiliation(s)
- Marsel Z Shafikov
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstrasse 31, Regensburg D-93053, Germany.,Department for Technology of Organic Synthesis, Institute of Chemical Technology, Ural Federal University, Mira 19, Ekaterinburg 620002, Russia
| | - Andrey V Zaytsev
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, U.K
| | - Valery N Kozhevnikov
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, U.K
| |
Collapse
|
21
|
Beucher H, Kumar S, Kumar R, Merino E, Hu WH, Stemmler G, Cuesta-Galisteo S, González JA, Bezinge L, Jagielski J, Shih CJ, Nevado C. Phosphorescent κ 3 -(N^C^C)-Gold(III) Complexes: Synthesis, Photophysics, Computational Studies and Application to Solution-Processable OLEDs. Chemistry 2020; 26:17604-17612. [PMID: 32780903 DOI: 10.1002/chem.202003571] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Indexed: 12/19/2022]
Abstract
Efficient OLED devices have been fabricated using organometallic complexes of platinum group metals. Still, the high material cost and low stability represent central challenges for their application in commercial display technologies. Based on its innate stability, gold(III) complexes are emerging as promising candidates for high-performance OLEDs. Here, a series of alkynyl-, N-heterocyclic carbene (NHC)- and aryl-gold(III) complexes stabilized by a κ3 -(N^C^C) template have been prepared and their photophysical properties have been characterized in detail. These compounds exhibit good photoluminescence quantum efficiency (ηPL ) of up to 33 %. The PL emission can be tuned from sky-blue to yellowish green colors by variations on both the ancillary ligands as well as on the pincer template. Further, solution-processable OLED devices based on some of these complexes display remarkable emissive properties (ηCE 46.6 cd.A-1 and ηext 14.0 %), thus showcasing the potential of these motifs for the low-cost fabrication of display and illumination technologies.
Collapse
Affiliation(s)
- Hélène Beucher
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Sudhir Kumar
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Roopender Kumar
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Estíbaliz Merino
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Wei-Hsu Hu
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Gerrit Stemmler
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Sergio Cuesta-Galisteo
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Jorge A González
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Léonard Bezinge
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Jakub Jagielski
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Chih-Jen Shih
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Cristina Nevado
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| |
Collapse
|
22
|
Zheng Q, Borsley S, Tu T, Cockroft SL. Reversible stimuli-responsive chromism of a cyclometallated platinum(II) complex. Chem Commun (Camb) 2020; 56:14705-14708. [PMID: 33170199 DOI: 10.1039/d0cc06775j] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We report the reversible chromism and luminescence of a cyclometalated platinum(ii) complex that forms dimers, with close PtPt interactions that can be modulated by solvent and temperature. The precise reversible control may be exploited in future stimuli-responsive chemosensing or optoelectronic devices.
Collapse
Affiliation(s)
- Qingshu Zheng
- EaStCHEM School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, UK. and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Stefan Borsley
- EaStCHEM School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, UK.
| | - Tao Tu
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Scott L Cockroft
- EaStCHEM School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, UK.
| |
Collapse
|
23
|
Hao Z, Zhang K, Chen K, Lu Z, Wang P, Zhu W, Liu Y. An Effective Approach to Obtain Near-Infrared Emission from Binuclear Platinum(II) Complexes Involving Thiophenpyridine-Isoquinoline Bridging Ligand in Solution-Processed OLEDs. Chem Asian J 2020; 15:3003-3012. [PMID: 32721097 DOI: 10.1002/asia.202000544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/28/2020] [Indexed: 11/08/2022]
Abstract
Bimetallic complexes have become an emerging hot topic in field of luminous applications in recent years. Unlike the traditional modification on a cyclometalated ligand, grafting an additional metal ion provides a novel approach to tune molecular conjugation as well as the spin orbital coupling (SOC). Herein, we demonstrate a new kind of binuclear platinum(II) complex Pt-3 that possesses an asymmetric thiophenpyridine-isoquinoline bridging ligand. Compared to its mononuclear analogues of Pt-1 and Pt-2, an extremely large redshift emission from 576 and 618 nm to 721 nm was observed in solution. Binding of two metal ions helps to enhance molecular planarity, extend conjugation and suppress excited state distortion. However, their quantum yields tend to remarkably decrease with increasing red-shift emission as following the "energy gap law". The relatively larger HOMO/LUMO separation that induced by the second platinum ion also decreases the oscillator strength at the lowest singlet state, and goes against the fast radiative decay process. Solution-processed organic light-emitting diodes (OLEDs) based on Pt-1, Pt-2 and Pt-3 achieved external quantum efficiencies (EQEs) and luminance/radiant emittance of 13.6% and 13640 cd/m2 , 3.5% and 3754 cd/m2 , 0.9% and 7981 mW/Sr/m2 with the corresponding electroluminescent (EL) emission peaked at 580 nm, 625 nm and 708 nm, respectively. This work emphasizes the complement argument of the commonly largely reported symmetric binuclear configurations, and provides a new view to photophysical mechanism and design strategies for bimetallic species.
Collapse
Affiliation(s)
- Zhaoran Hao
- College of Chemistry, Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan, 411105, China
| | - Kai Zhang
- School of Materials Science and Engineering, Jiangsu Collaboration Innovation, Center of Photovoltaic Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-, Converting Materials and Applications, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou, 213164, China
| | - Kuan Chen
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Zhiyun Lu
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Pu Wang
- College of Chemistry, Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan, 411105, China
| | - Weiguo Zhu
- School of Materials Science and Engineering, Jiangsu Collaboration Innovation, Center of Photovoltaic Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-, Converting Materials and Applications, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou, 213164, China
| | - Yu Liu
- School of Materials Science and Engineering, Jiangsu Collaboration Innovation, Center of Photovoltaic Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-, Converting Materials and Applications, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou, 213164, China.,College of Chemistry, Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan, 411105, China
| |
Collapse
|
24
|
Chakraborty S, Aliprandi A, De Cola L. Multinuclear Pt II Complexes: Why Three is Better Than Two to Enhance Photophysical Properties. Chemistry 2020; 26:11007-11012. [PMID: 32329122 PMCID: PMC7496982 DOI: 10.1002/chem.202001510] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Indexed: 01/31/2023]
Abstract
The self-assembly of platinum complexes is a well-documented process that leads to interesting changes of the photophysical and electrochemical behavior as well as to a change in reactivity of the complexes. However, it is still not clear how many metal units must interact in order to achieve the desired properties of a large assembly. This work aimed to clarify the role of the number of interacting PtII units leading to an enhancement of the spectroscopic properties and how to address inter- versus intramolecular processes. Therefore, a series of neutral multinuclear PtII complexes were synthesized and characterized, and their photophysical properties at different concentration were studied. Going from the monomer to dimers, the growth of a new emission band and the enhancement of the emission properties were observed. Upon increasing the platinum units up to three, the monomeric blue emission could not be detected anymore and a concentration independent bright-yellow/orange emission, due to the establishment of intramolecular metallophilic interactions, was observed.
Collapse
Affiliation(s)
- Sourav Chakraborty
- Institut de Science et d'Ingénierie SupramoléculairesCNRS, UMR 7006, Université de Strasbourg8 rue Gaspard Monge67000StrasbourgFrance
| | - Alessandro Aliprandi
- Institut de Science et d'Ingénierie SupramoléculairesCNRS, UMR 7006, Université de Strasbourg8 rue Gaspard Monge67000StrasbourgFrance
| | - Luisa De Cola
- Institut de Science et d'Ingénierie SupramoléculairesCNRS, UMR 7006, Université de Strasbourg8 rue Gaspard Monge67000StrasbourgFrance
- Institute for Nanotechnology (INT)Karlsruhe Institute of TechnologyHermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
| |
Collapse
|
25
|
Hao Z, Zhang K, Chen K, Wang P, Lu Z, Zhu W, Liu Y. More efficient spin-orbit coupling: adjusting the ligand field strength to the second metal ion in asymmetric binuclear platinum(ii) configurations. Dalton Trans 2020; 49:8722-8733. [PMID: 32555914 DOI: 10.1039/d0dt00939c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Two types of asymmetric binuclear platinum(ii) complexes (Pt-1 and Pt-3) bearing bridging ligands of 2-(2,4-difluorophenyl)-5-(pyridin-2-yl)pyridine and 2-(2,4-difluorophenyl)-4-(pyridin-2-yl)pyridine as well as their corresponding mononuclear counterparts (Pt-2, Pt-4, and Pt-5) were synthesized and characterized. Different chelating constructions of the second platinum(ii) ions and the bridging ligands in Pt-1 and Pt-3 gave rise to two kinds of electron-transition pathway during their photophysical processes. The meta-/para-carbon of nitrogen on the center pyridyl segments set different levels of ligand field strength to the second platinum(ii) ions, lowering their occupied d orbital to varying degrees. Pt-1 showed an enhanced spin-orbit coupling (SOC), caused by the additional metal component through direct orbital hybridization at higher states, where the fixed molecular skeleton induced by the additional metal-ligand bonding also helped to suppress molecular distortion in the excited state, ensuring a high quantum yield (Φ, 0.89 in toluene), which is among the best results in bimetallic complexes. While the second platinum(ii) ion in Pt-3 seemed to make no contribution to the radiative transition, and only contributed to the HOMO, it provided a benefit by enlarging the conjugate system. Solution-processed organic lighting emitting devices (OLEDs) fabricated with the bimetallic Pt-1 emitter achieved superior efficiencies and up to 21% external quantum efficiency (EQE) in the Kelly-green region.
Collapse
Affiliation(s)
- Zhaoran Hao
- College of Chemistry, Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, China.
| | | | | | | | | | | | | |
Collapse
|
26
|
Sicilia V, Arnal L, Chueca AJ, Fuertes S, Babaei A, Igual Muñoz AM, Sessolo M, Bolink HJ. Highly Photoluminescent Blue Ionic Platinum-Based Emitters. Inorg Chem 2020; 59:1145-1152. [PMID: 31880921 DOI: 10.1021/acs.inorgchem.9b02782] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
New cycloplatinated N-heterocyclic carbene (NHC) compounds with chelate diphosphines (P^P) as ancillary ligands: [Pt(R-C^C*)(P^P)]PF6 (R = H, P^P = dppm (1A), dppe (2A), dppbz (3A); R = CN, P^P = dppm (1B), dppe (2B), dppbz (3B)) have been prepared from the corresponding starting material [{Pt(R-C^C*)(μ-Cl)}2] (R = H, A, R = CN, B) and fully characterized. The new compound A has been prepared by a stepwise protocol. The photophysical properties of 1A-3A and 1B-3B have been widely studied and supported by the time-dependent-density functional theory. These compounds show an efficient blue (dppe, dppbz) or cyan (dppm) emission in PMMA films (5 wt %), with photoluminescence quantum yield (PLQY) ranging from 30% to 87% under an argon atmosphere. This emission has been assigned mainly to transitions from 3ILCT [π(NHC) → π*(NHC)] excited states with some 3LL'CT [π(NHC) → π*(P^P)] character. The electroluminescence of these materials in proof-of-concept solution-processed organic light-emitting diodes containing 3A and 3B as dopants was investigated. The CIE coordinates for devices based on 3A (0.22, 0.41) and 3B (0.24, 0.44) fit within the sky blue region.
Collapse
Affiliation(s)
- Violeta Sicilia
- Departamento de Química Inorgánica, Escuela de Ingeniería y Arquitectura de Zaragoza, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH) , CSIC - Universidad de Zaragoza , Campus Río Ebro, Edificio Torres Quevedo , 50018 , Zaragoza , Spain
| | - Lorenzo Arnal
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH) , CSIC - Universidad de Zaragoza , Pedro Cerbuna 12 , 50009 , Zaragoza , Spain
| | - Andrés J Chueca
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH) , CSIC - Universidad de Zaragoza , Pedro Cerbuna 12 , 50009 , Zaragoza , Spain
| | - Sara Fuertes
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH) , CSIC - Universidad de Zaragoza , Pedro Cerbuna 12 , 50009 , Zaragoza , Spain
| | - Azin Babaei
- Instituto de Ciencia Molecular , Universidad de Valencia , C/J. Beltran 2 , 46980 , Paterna , Spain
| | - Ana María Igual Muñoz
- Instituto de Ciencia Molecular , Universidad de Valencia , C/J. Beltran 2 , 46980 , Paterna , Spain
| | - Michele Sessolo
- Instituto de Ciencia Molecular , Universidad de Valencia , C/J. Beltran 2 , 46980 , Paterna , Spain
| | - Henk J Bolink
- Instituto de Ciencia Molecular , Universidad de Valencia , C/J. Beltran 2 , 46980 , Paterna , Spain
| |
Collapse
|
27
|
Zhang Z, Tizzard GJ, Williams JAG, Goldup SM. Rotaxane Pt II-complexes: mechanical bonding for chemically robust luminophores and stimuli responsive behaviour. Chem Sci 2020; 11:1839-1847. [PMID: 34123277 PMCID: PMC8148368 DOI: 10.1039/c9sc05507j] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report an approach to rotaxanes in which the metal ion of a cyclometallated PtII luminophore is embedded in the space created by the mechanical bond. Our results show that the interlocked ligand environment stabilises a normally labile PtII–triazole bond against displacement by competing ligands and that the crowded environment of the mechanical bond retards oxidation of the PtII centre, without perturbing the photophysical properties of the complex. When an additional pyridyl binding site is included in the axle, the luminescence of the PtII centre is quenched, an effect that can be selectively reversed by the binding of AgI. Our results suggest that readily available interlocked metal-based phosphors can be designed to be stimuli responsive and have advantages as stabilised triplet harvesting dopants for device applications. We report an approach to interlocked PtII luminophores in which the mechanical bond stabilises the coordination environment of the embedded metal ion.![]()
Collapse
Affiliation(s)
- Zhihui Zhang
- Chemistry, University of Southampton Southampton SO51 5PG UK
| | | | | | | |
Collapse
|
28
|
Kabir E, Wu Y, Sittel S, Nguyen BL, Teets TS. Improved deep-red phosphorescence in cyclometalated iridium complexes via ancillary ligand modification. Inorg Chem Front 2020. [DOI: 10.1039/c9qi01584a] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Bis-cyclometalated iridium complexes with electron-rich ancillary ligands exhibit high phosphorescence quantum yields in the deep red region.
Collapse
Affiliation(s)
- Evanta Kabir
- Department of Chemistry
- University of Houston
- Houston
- USA
| | - Yanyu Wu
- Department of Chemistry
- University of Houston
- Houston
- USA
| | - Steven Sittel
- Department of Chemistry
- University of Houston
- Houston
- USA
| | | | | |
Collapse
|
29
|
Puttock EV, Sil A, Yufit DS, Williams JAG. Mono and dinuclear iridium(iii) complexes featuring bis-tridentate coordination and Schiff-base bridging ligands: the beneficial effect of a second metal ion on luminescence. Dalton Trans 2020; 49:10463-10476. [DOI: 10.1039/d0dt01964j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ditopic bis-N^N^O-coordinating ligands, prepared by Schiff base chemistry, lead to dinuclear iridium complexes that emit much more brightly than their mononuclear counterparts.
Collapse
Affiliation(s)
| | - Amit Sil
- Department of Chemistry
- Durham University
- Durham
- UK
| | | | | |
Collapse
|
30
|
Shafikov MZ, Daniels R, Kozhevnikov VN. Unusually Fast Phosphorescence from Ir(III) Complexes via Dinuclear Molecular Design. J Phys Chem Lett 2019; 10:7015-7024. [PMID: 31638816 DOI: 10.1021/acs.jpclett.9b03002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The design and detailed photophysical study of two novel Ir(III) complexes featuring mono- and dinuclear design are presented. Emission quantum yield and decay times in solution are ΦPL = 90% and τ(300 K) = 1.16 μs for the mononuclear complex 5, and ΦPL = 95% and τ(300 K) = 0.44 μs for the dinuclear complex 6. These data indicate an almost 3-fold increase in the phosphorescence rate for dinuclear complex 6 compared to 5. Zero-field splitting (ZFS) of the T1 state also increases from ZFS = 65 cm-1 for the mononuclear complex to ZFS = 205 cm-1 for the dinuclear complex and is accompanied by a drastic shortening of the individual decay times of T1 substates. With the help of TD-DFT calculations, we rationalize that the drastic changes in the T1 state properties in the dinuclear complex originate from an increased number of excited states available for direct spin-orbit coupling (SOC) routes as a result of electronic coupling of Ir-Cl antibonding molecular orbitals of the two coordination sites.
Collapse
Affiliation(s)
- Marsel Z Shafikov
- Institut für Physikalische und Theoretische Chemie , Universität Regensburg , Universitätsstrasse 31 , Regensburg D-93053 , Germany
- Ural Federal University , Mira 19 , Ekaterinburg 620002 , Russia
| | - Ruth Daniels
- Department of Applied Sciences , Northumbria University , Newcastle upon Tyne NE1 8ST , United Kingdom
| | - Valery N Kozhevnikov
- Department of Applied Sciences , Northumbria University , Newcastle upon Tyne NE1 8ST , United Kingdom
| |
Collapse
|
31
|
Mandapati P, Braun JD, Killeen C, Davis RL, Williams JAG, Herbert DE. Luminescent Platinum(II) Complexes of N^N–^N Amido Ligands with Benzannulated N-Heterocyclic Donor Arms: Quinolines Offer Unexpectedly Deeper Red Phosphorescence than Phenanthridines. Inorg Chem 2019; 58:14808-14817. [DOI: 10.1021/acs.inorgchem.9b02480] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Pavan Mandapati
- Department of Chemistry and the Manitoba Institute for Materials, University of Manitoba, 144 Dysart Road, Winnipeg, Manitoba R3T 2N2, Canada
| | - Jason D. Braun
- Department of Chemistry and the Manitoba Institute for Materials, University of Manitoba, 144 Dysart Road, Winnipeg, Manitoba R3T 2N2, Canada
| | - Charles Killeen
- Department of Chemistry and the Manitoba Institute for Materials, University of Manitoba, 144 Dysart Road, Winnipeg, Manitoba R3T 2N2, Canada
| | - Rebecca L. Davis
- Department of Chemistry and the Manitoba Institute for Materials, University of Manitoba, 144 Dysart Road, Winnipeg, Manitoba R3T 2N2, Canada
| | | | - David E. Herbert
- Department of Chemistry and the Manitoba Institute for Materials, University of Manitoba, 144 Dysart Road, Winnipeg, Manitoba R3T 2N2, Canada
| |
Collapse
|
32
|
Wei F, Lai SL, Zhao S, Ng M, Chan MY, Yam VWW, Wong KMC. Ligand Mediated Luminescence Enhancement in Cyclometalated Rhodium(III) Complexes and Their Applications in Efficient Organic Light-Emitting Devices. J Am Chem Soc 2019; 141:12863-12871. [PMID: 31310721 DOI: 10.1021/jacs.9b06308] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A series of luminescent cyclometalated rhodium(III) complexes have been designed and prepared. The improved luminescence property is realized by the judicious choice of a strong σ-donor cyclometalating ligand with a lower-lying intraligand (IL) state that would raise the d-d excited state and introduction of a lower-lying emissive IL excited state. These complexes exhibit high thermal stability and considerable luminescence quantum yields as high as up to 0.65 in thin film, offering themselves as promising light-emitting materials in OLEDs. Respectable external quantum efficiencies of up to 12.2% and operational half-lifetimes of over 3000 h at 100 cd m-2 have been achieved. This work demonstrates a breakthrough as the first example of an efficient rhodium(III) emitter for OLED application and opens up a new avenue for diversifying the development of OLED materials with rhodium metal being utilized as phosphors.
Collapse
Affiliation(s)
- Fangfang Wei
- Department of Chemistry , Southern University of Science and Technology , 1088 Xueyuan Blvd. , Shenzhen 518055 , PR China
| | - Shiu-Lun Lai
- Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee, Hong Kong) and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| | - Shunan Zhao
- Department of Chemistry , Southern University of Science and Technology , 1088 Xueyuan Blvd. , Shenzhen 518055 , PR China
| | - Maggie Ng
- Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee, Hong Kong) and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| | - Mei-Yee Chan
- Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee, Hong Kong) and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| | - Vivian Wing-Wah Yam
- Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee, Hong Kong) and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| | - Keith Man-Chung Wong
- Department of Chemistry , Southern University of Science and Technology , 1088 Xueyuan Blvd. , Shenzhen 518055 , PR China
| |
Collapse
|