1
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Watanabe H, Iwamura M, Nozaki K. Kinetic Analysis of Excited-State Dynamics of Emissive Oligomers of Pt(II) Complex in Solution. Inorg Chem 2024; 63:5580-5585. [PMID: 38477493 DOI: 10.1021/acs.inorgchem.3c04542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
[Pt(NCN)MeCN]+ (NCN = 1,3-di(2-pyridyl)benzene, MeCN = acetonitrile) forms oligomers, such as dimers and trimers, in solutions due to metallophilic interactions. The emission and absorption spectra in the visible region are considerably changed by the concentrations of the solutions because the excitation energy of the oligomers is dependent on the degree of oligomerization. In this study, excited-state dynamics of [Pt(NCN)MeCN]+ in acetonitrile were investigated by time-resolved emission spectroscopy in time regions from microseconds to nanoseconds at various concentrations. The time-resolved emission spectra recorded with 355 nm photoexcitation showed the decay of the blue-green emission and the rise of the red emission in the microsecond time region. Stern-Volmer analysis of the time-resolved data at various concentrations and wavelengths provides two bimolecular rate constants (4.1 × 109 and 8.2 × 108 M-1 s-1) for the formation processes of the excited-state T1 dimer and T1 trimer, respectively. Kinetic parameters, such as the intrinsic decay rate constants of the T1 monomer, T1 dimer, and T1 trimer, and the association and dissociation rate constants of the T1 dimer and T1 trimer were estimated by fitting the time-resolved emission data at various concentrations.
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Affiliation(s)
- Honoka Watanabe
- Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan
| | - Munetaka Iwamura
- Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan
| | - Koichi Nozaki
- Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan
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2
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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: 0] [Impact Index Per Article: 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.
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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
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3
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Tang Z, Song Y, Zhang S, Wang W, Xu Y, Wu D, Wu W, Su P. XEDA, a fast and multipurpose energy decomposition analysis program. J Comput Chem 2021; 42:2341-2351. [PMID: 34626430 DOI: 10.1002/jcc.26765] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/16/2021] [Accepted: 09/22/2021] [Indexed: 01/06/2023]
Abstract
A fast and multipurpose energy decomposition analysis (EDA) program, called XEDA, is introduced for quantitative analysis of intermolecular interactions. This program contains a series of variational EDA methods, including LMO-EDA, GKS-EDA and their extensions, to analyze non-covalent interactions and strong chemical bonds in various environments. XEDA is highly efficient with a similar computational scaling of single point energy calculations. Its efficiency and universality are validated by a series of test examples including van der Waals interactions, hydrogen bonds, radical-radical interactions and strong covalent bonds.
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Affiliation(s)
- Zhen Tang
- The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Yanlin Song
- The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Shu Zhang
- The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Wei Wang
- The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Yuan Xu
- The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Di Wu
- The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Wei Wu
- The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Peifeng Su
- The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
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4
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Kumar P, Escudero D. Computational Protocol to Calculate the Phosphorescence Energy of Pt(II) Complexes: Is the Lowest Triplet Excited State Always Involved in Emission? A Comprehensive Benchmark Study. Inorg Chem 2021; 60:17230-17240. [PMID: 34702026 DOI: 10.1021/acs.inorgchem.1c02562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The reliable calculation of phosphorescence energies of phosphor materials is at the core of designing efficient phosphorescent organic light-emitting diodes (PhOLEDs). Therefore, it is of paramount importance to have a robust computational protocol to perform those calculations in a black-box manner. In this work, we use Domain-Based Local Pair Natural Orbital Coupled Cluster theory with single, double, and perturbative triple excitation (DLPNO-CCSD(T)) calculations to attain the phosphorescence energies of a large pool of Pt(II) complexes. Several approaches to incorporate relativistic effects in our calculations were tested. In addition, we have used the DLPNO-CCSD(T) values (i.e., our best theoretical values) to assess the performance of different flavors of density functional theory including pure, hybrid, meta-hybrid, and range-separated functionals. Among the tested functionals, the M06HF functional provides the best values compared with the DLPNO-CCSD(T) ones, with a mean absolute deviation (MAD) value of 0.14 eV. In its turn, and thanks to the increased accuracy achieved in the calculation of phosphorescence energies, we also demonstrate that not all of the investigated complexes emit from their lowest-lying triplet state (T1). The outlier complexes include different complex photophysical scenarios and both Kasha and anti-Kasha types of complexes. Finally, we provide a general computational protocol to pre-screen whether T1 is actually the emissive state and to accurately calculate the phosphorescence energies of Pt(II) complexes.
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Affiliation(s)
- Prashant Kumar
- Quantum Chemistry and Physical Chemistry Section, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Daniel Escudero
- Quantum Chemistry and Physical Chemistry Section, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
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5
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Sicilia V, Arnal L, Escudero D, Fuertes S, Martin A. Chameleonic Photo- and Mechanoluminescence in Pyrazolate-Bridged NHC Cyclometalated Platinum Complexes. Inorg Chem 2021; 60:12274-12284. [PMID: 34339189 PMCID: PMC8892954 DOI: 10.1021/acs.inorgchem.1c01470] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
DFT investigations on the ground (GS) and the first triplet (T1) excited state potential energy surfaces (PES) were performed on a new series of platinum-butterfly complexes, [{Pt(C∧C*)(μ-Rpz)}2] (Rpz: pz, 1; 4-Mepz, 2; 3,5-dmpz, 3; 3,5-dppz, 4), containing a cyclometalated NHC in their wings. The geometries of two close-lying local minima corresponding to butterfly spread conformers, 1s-4s, and butterfly folded ones, 1f-4f, with long and short Pt-Pt separations, respectively, were optimized in the GS and T1 PES. A comparison of the GS and T1 energy profiles revealed that an opposite trend is obtained in the relative stability of folded and spread conformers, the latter being more stabilized in their GS. Small ΔG (s/f) along with small-energy barriers in the GS support the coexistence of both kinds of conformers, which influence the photo- and mechanoluminescence of these complexes. In 5 wt % doped PMMA films in the air, these complexes exhibit intense sky-blue emissions (PLQY: 72.0-85.9%) upon excitation at λ ≤ 380 nm arising from 3IL/MLCT excited states, corresponding to the predominant 1s-4s conformers. Upon excitation at longer wavelengths (up to 450 nm), the minor 1f-4f conformers afford a blue emission as well, with PLQY still significant (40%-60%). In the solid state, the as-prepared powder of 4 exhibits a greenish-blue emission with QY ∼ 29%, mainly due to 3IL/3MLCT excited states of butterfly spread molecules, 4s. Mechanical grinding resulted in an enhanced and yellowish-green emission (QY ∼ 51%) due to the 3MMLCT excited states of butterfly folded molecules, 4f, in such a way that the mechanoluminescence has been associated with an intramolecular structural change induced by mechanical grinding.
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Affiliation(s)
- Violeta Sicilia
- Departamento de Quimica Inorganica, Escuela de Ingenieria y Arquitectura de Zaragoza, Instituto de Sintesis Quimica y Catalisis Homogenea (ISQCH), CSIC - Universidad de Zaragoza, Campus Rio Ebro, Edificio Torres Quevedo, 50018, Zaragoza, Spain
| | - Lorenzo Arnal
- Departamento de Quimica Inorganica, Facultad de Ciencias, Instituto de Sintesis Quimica y Catalisis Homogenea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Daniel Escudero
- Department of Chemistry, KU Leuven, Celestijnenlaan 200f - box 2404, 3001 Leuven, Belgium
| | - Sara Fuertes
- Departamento de Quimica Inorganica, Facultad de Ciencias, Instituto de Sintesis Quimica y Catalisis Homogenea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Antonio Martin
- Departamento de Quimica Inorganica, Facultad de Ciencias, Instituto de Sintesis Quimica y Catalisis Homogenea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
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6
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Su BK, Wei YC, Chuang WT, Weng SC, Wang SF, Chen DG, Huang ZX, Chi Y, Chou PT. The Observation of Interchain Motion in Self-Assembled Crystalline Platinum(II) Complexes: An Exquisite Case but By No Means the Only One in Molecular Solids. J Phys Chem Lett 2021; 12:7482-7489. [PMID: 34342467 DOI: 10.1021/acs.jpclett.1c01677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In organic and organometallic solids, upon electronic excitation, most intermolecular structural relaxations follow a pathway along the π-π stacking direction or metal-metal bond with significant coupling strength. Differently, we discovered that the self-assembled platinum(II) complexes, Pt(fppz)2, exhibit an unusual interchain contraction. The ground-state and excited-state multiple local minima were distinguished by temperature-dependent excitation/emission spectra, indicating the existence of multiple local minima. The time-resolved emission decay revealed the excited-state structural relaxation lifetime with τobs = 41 ns at 298 K. Temperature-dependent X-ray diffraction analysis showed that the packing geometries contract 0.6 Å along the interchain direction (a-axis) at 50 K compared to the geometries at 298 K. Such structural displacements render the slow internal conversion rate in the excited states. We thus demonstrate the correlation between the packing geometries and the excited-state dynamics of the self-assembled Pt(II) complexes, shedding light on the unique direction of interchain structural deformation of the molecular aggregates.
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Affiliation(s)
- Bo-Kang Su
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Yu-Chen Wei
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Wei-Tsung Chuang
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Shih-Chang Weng
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Sheng-Fu Wang
- Department of Chemistry and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Deng-Gao Chen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Zhi-Xuan Huang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Yun Chi
- Department of Chemistry and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Materials Science and Engineering, Department of Chemistry, and Center of Super-Diamond and Advanced Films, City University of Hong Kong, Kowloon 999077, Hong Kong SAR
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
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7
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Veclani D, Tolazzi M, Cerón-Carrasco JP, Melchior A. Intercalation Ability of Novel Monofunctional Platinum Anticancer Drugs: A Key Step in Their Biological Action. J Chem Inf Model 2021; 61:4391-4399. [PMID: 34156233 PMCID: PMC8479807 DOI: 10.1021/acs.jcim.1c00430] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
Phenanthriplatin
(PtPPH) is a monovalent platinum(II)-based complex
with a large cytotoxicity against cancer cells. Although the aqua-activated
drug has been assumed to be the precursor for DNA damage, it is still
under debate whether the way in which that metallodrug attacks to
DNA is dominated by a direct binding to a guanine base or rather by
an intercalated intermediate product. Aiming to capture the mechanism
of action of PtPPH, the present contribution used theoretical tools
to systematically assess the sequence of all possible mechanisms on
drug activation and reactivity, for example, hydrolysis, intercalation,
and covalent damage to DNA. Ab initio quantum mechanical
(QM) methods, hybrid QM/QM′ schemes, and independent gradient
model approaches are implemented in an unbiased protocol. The performed
simulations show that the cascade of reactions is articulated in three
well-defined stages: (i) an early and fast intercalation of the complex
between the DNA bases, (ii) a subsequent hydrolysis reaction that
leads to the aqua-activated form, and (iii) a final formation of the
covalent bond between PtPPH and DNA at a guanine site. The permanent
damage to DNA is consequently driven by that latter bond to DNA but
with a simultaneous π–π intercalation of the phenanthridine
into nucleobases. The impact of the DNA sequence and the lateral backbone
was also discussed to provide a more complete picture of the forces
that anchor the drug into the double helix.
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Affiliation(s)
- Daniele Veclani
- Dipartimento Politecnico di Ingegneria e Architettura (DPIA), Laboratori di Chimica, Università di Udine, via delle Scienze 99, 33100 Udine, Italy
| | - Marilena Tolazzi
- Dipartimento Politecnico di Ingegneria e Architettura (DPIA), Laboratori di Chimica, Università di Udine, via delle Scienze 99, 33100 Udine, Italy
| | - José P Cerón-Carrasco
- Reconocimiento y Encapsulación Molecular, Universidad Católica San Antonio de Murcia (UCAM). Campus de los Jerónimos, 30107 Murcia, Spain
| | - Andrea Melchior
- Dipartimento Politecnico di Ingegneria e Architettura (DPIA), Laboratori di Chimica, Università di Udine, via delle Scienze 99, 33100 Udine, Italy
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