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Kirse TM, Maisuls I, Cappellari MV, Niehaves E, Kösters J, Hepp A, Karst U, Wolcan E, Strassert CA. Neutral and Cationic Re(I) Complexes with Pnictogen-Based Coligands and Tunable Functionality: From Phosphorescence to Photoinduced CO Release. Inorg Chem 2024; 63:4132-4151. [PMID: 38382545 DOI: 10.1021/acs.inorgchem.3c03886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
In this work, we have explored Re(I) complexes featuring triphenylpnictogen (PnPh3, Pn = P, As, or Sb)-based coligands and bidentate (neutral or monoanionic) luminophores derived from 1,10-phenantroline (phen), as well as from 2-(3-(tert-butyl)-1H-1,2,4-triazol-5-yl)pyridine (H(N-tBu)). The effect of the increasingly heavy elements on the structural parameters, photoexcited-state properties, and electrochemical behavior as well as the hybridization defects and polarization of the Pn atoms was related to the charges of the main luminophores (i.e., phen vs N-tBu) and explored in terms of photoluminescence spectroscopy, X-ray diffractometry, and quantum-chemical methods. Therefore, an in-depth analysis of the bonding, crystal packing, excited-state energies, and lifetimes was assessed in liquid solutions, frozen glassy matrices, and crystalline phases along with a semiquantitative photoactivation study. Notably, by changing the main ligand from phen to N-tBu, an increase in radiative and radiationless deactivation rates (kr and knr, respectively) at 77 K together with a faster photoinduced CO release and fragmentation at room temperature was detected. In addition, a progressively red-shifted phosphorescence was observed with the growing atomic number of the pnictogen atom, along with a boost in kr and knr at 77 K. Down the Vth main group and upon coordination of the Pn atom to the Re(I) center, an increasingly prominent jump of s-orbital participation on the binding sxp3.00-orbitals of the Pn atoms is evidenced. Based on these findings, the ability of these complexes to act as tunable photoluminescent labels able to perform as light-driven CO-releasing molecules is envisioned.
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Affiliation(s)
- Thomas M Kirse
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany
- CiMiC, SoN and CeNTech, Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Iván Maisuls
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany
- CiMiC, SoN and CeNTech, Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - María Victoria Cappellari
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany
- CiMiC, SoN and CeNTech, Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Erik Niehaves
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany
| | - Jutta Kösters
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany
| | - Uwe Karst
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany
| | - Ezequiel Wolcan
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, UNLP, CCT La Plata-CONICET), Diagonal 113 and 64, Sucursal 4, Casilla de Correo 16, La Plata B1906, Argentina
| | - Cristian A Strassert
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany
- CiMiC, SoN and CeNTech, Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
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Kirse TM, Maisuls I, Spierling L, Hepp A, Kösters J, Strassert CA. One Dianionic Luminophore with Three Coordination Modes Binding Four Different Metals: Toward Unexpectedly Phosphorescent Transition Metal Complexes. Adv Sci (Weinh) 2024; 11:e2306801. [PMID: 38161218 PMCID: PMC10953592 DOI: 10.1002/advs.202306801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/08/2023] [Indexed: 01/03/2024]
Abstract
This work reports on a battery of coordination compounds featuring a versatile dianionic luminophore adopting three different coordination modes (mono, bi, and tridentate) while chelating Pd(II), Pt(II), Au(III), and Hg(II) centers. An in-depth structural characterization of the ligand precursor (H2 L) and six transition metal complexes ([HLPdCNtBu], [LPtCl], [LPtCNtBu], [LPtCNPhen], [HLHgCl], and [LAuCl]) is presented. The influence of the cations and coordination modes of the luminophore and co-ligands on the photophysical properties (including photoluminescence quantum yields (ΦL ), excited state lifetimes (τ), and average (non-)radiative rate constants) are evaluated at various temperatures in different phases. Five complexes show interesting photophysical properties at room temperature (RT) in solution. Embedment in frozen glassy matrices at 77 K significantly boosts their luminescence by suppressing radiationless deactivation paths. Thus, the Pt(II)-based compounds provide the highest efficiencies, with slight variations upon exchange of the ancillary ligand. In the case of [HLPdCNtBu], both ΦL and τ increase over 30-fold as compared to RT. Furthermore, the Hg(II) complex achieves, for the first time in its class, a ΦL exceeding 60% and millisecond-range lifetimes. This demonstrates that a judicious ligand design can pave the way toward versatile coordination compounds with tunable excited state properties.
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Affiliation(s)
- Thomas M. Kirse
- Institut für Anorganische und Analytische ChemieUniversität MünsterCorrensstr. 28/3048149MünsterGermany
- CiMiCSoN and CeNTechUniversität MünsterHeisenbergstr. 1148149MünsterGermany
| | - Iván Maisuls
- Institut für Anorganische und Analytische ChemieUniversität MünsterCorrensstr. 28/3048149MünsterGermany
- CiMiCSoN and CeNTechUniversität MünsterHeisenbergstr. 1148149MünsterGermany
| | - Leander Spierling
- Institut für Anorganische und Analytische ChemieUniversität MünsterCorrensstr. 28/3048149MünsterGermany
- CiMiCSoN and CeNTechUniversität MünsterHeisenbergstr. 1148149MünsterGermany
| | - Alexander Hepp
- Institut für Anorganische und Analytische ChemieUniversität MünsterCorrensstr. 28/3048149MünsterGermany
| | - Jutta Kösters
- Institut für Anorganische und Analytische ChemieUniversität MünsterCorrensstr. 28/3048149MünsterGermany
| | - Cristian A. Strassert
- Institut für Anorganische und Analytische ChemieUniversität MünsterCorrensstr. 28/3048149MünsterGermany
- CiMiCSoN and CeNTechUniversität MünsterHeisenbergstr. 1148149MünsterGermany
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Jordan R, Maisuls I, Nair SS, Dietzek-Ivanšić B, Strassert CA, Klein A. Enhanced luminescence properties through heavy ancillary ligands in [Pt(C^N^C)(L)] complexes, L = AsPh 3 and SbPh 3. Dalton Trans 2023. [PMID: 38013458 DOI: 10.1039/d3dt03225f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
In the frame of our research aiming to develop efficient triplet-emitting materials, we are exploring the concept of introducing additional heavy atoms into cyclometalated transition metal complexes to enhance intersystem-crossing (ISC) and thus triplet emission through increased spin-orbit coupling (SOC). In an in-depth proof-of-principle study we investigated the double cyclometalated Pt(II) complexes [Pt(C^N^C)(PnPh3)] (HC^N^CH = 2,6-diphenyl-pyridine (H2dpp) or dibenzoacridine (H2dba); Pn = pnictogen atoms P, As, Sb, or Bi) through a combined experimental and theoretical approach. The derivatives containing Pn = P, As, and Sb were synthesised and characterised comprehensively using single crystal X-ray diffraction (scXRD), UV-vis absorption and emission spectroscopy, transient absorption (TA) spectroscopy and cyclic voltammetry (CV). Across the series P < As < Sb, a red-shift is observed concerning absorption and emission maxima as well as optical and electrochemical HOMO-LUMO gaps. Increased photoluminescence quantum yields ΦL and radiative rates kr from mixed metal-to-ligand charge transfer (MLCT)/ligand centred (LC) triplet states are observed for the heavier homologues. Transient absorption spectroscopy showed processes in the ps range that were assigned to the population of the T1 state by ISC. The heavy PnPh3 ancillary ligands are found to enhance the emission efficiency due to both higher Pt-Pn bond strength and stronger SOC related to increased MLCT character of the excited states. The experimental findings are mirrored in hybrid (TD-)DFT calculations. This allowed for extrapolation to the rather elusive Bi derivatives, which were synthetically not accessible. This shortcoming is attributed to the transmetalation of phenyl groups from BiPh3 to Pt, as supported by experimental NMR/MS as well as DFT studies.
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Affiliation(s)
- Rose Jordan
- University of Cologne, Faculty for Mathematics and Natural Sciences, Department of Chemistry, Institute for Inorganic Chemistry, Greinstrasse 6, D-50939 Köln, Germany.
| | - Iván Maisuls
- Universität Münster, Institut für Anorganische und Analytische Chemie, CiMIC, CeNTech, Heisenbergstraße 11, D-48149 Münster, Germany.
| | - Shruthi S Nair
- Friedrich Schiller University Jena, Institute for Physical Chemistry (IPC), Helmholtzweg 4, 07743 Jena, Germany.
- Leibniz Institute for Photonic Technologies Jena (IPHT), Research Department Functional Interfaces, Albert-Einstein-Str. 9, 07745 Jena, Germany.
| | - Benjamin Dietzek-Ivanšić
- Friedrich Schiller University Jena, Institute for Physical Chemistry (IPC), Helmholtzweg 4, 07743 Jena, Germany.
- Leibniz Institute for Photonic Technologies Jena (IPHT), Research Department Functional Interfaces, Albert-Einstein-Str. 9, 07745 Jena, Germany.
| | - Cristian A Strassert
- Universität Münster, Institut für Anorganische und Analytische Chemie, CiMIC, CeNTech, Heisenbergstraße 11, D-48149 Münster, Germany.
| | - Axel Klein
- University of Cologne, Faculty for Mathematics and Natural Sciences, Department of Chemistry, Institute for Inorganic Chemistry, Greinstrasse 6, D-50939 Köln, Germany.
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Gutierrez Suburu ME, Blanke M, Hepp A, Maus O, Schwab D, Doltsinis NL, Zeier WG, Giese M, Voskuhl J, Strassert CA. Pt(II) Complexes with Tetradentate C^N*N^C Luminophores: From Supramolecular Interactions to Temperature-Sensing Materials with Memory and Optical Readouts. Molecules 2023; 28:7353. [PMID: 37959770 PMCID: PMC10649584 DOI: 10.3390/molecules28217353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 10/10/2023] [Accepted: 10/17/2023] [Indexed: 11/15/2023] Open
Abstract
A series of four regioisomeric Pt(II) complexes (PtLa-n and PtLb-n) bearing tetradentate luminophores as dianionic ligands were synthesized. Hence, both classes of cyclometallating chelators were decorated with three n-hexyl (n = 6) or n-dodecyl (n = 12) chains. The new compounds were unambiguously characterized by means of multiple NMR spectroscopies and mass spectrometry. Steady-state and time-resolved photoluminescence spectroscopy as well quantum chemical calculations show that the effect of the regioisomerism on the emission colour and on the deactivation rate constants can be correlated with the participation of the Pt atom on the excited state. The thermal properties of the complexes were studied by DSC, POM and temperature-dependent steady-state photoluminescence spectroscopy. Three of the four complexes (PtLa-12, PtLb-6 and PtLb-12) present an intriguing thermochromism resulting from the responsive metal-metal interactions involving adjacent monomeric units. Each material has different transition temperatures and memory capabilities, which can be tuned at the intermolecular level. Hence, dipole-dipole interactions between the luminophores and disruption of the crystalline packing by the alkyl groups are responsible for the final properties of the resulting materials.
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Affiliation(s)
- Matias E. Gutierrez Suburu
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany
- Center of Nanotechnology (CeNTech), Center for Soft Nanosciences (SoN), Cells in Motion Interfaculty Cluster (CiMIC), Universität Münster, Heisenbergstraße 11, D-48149 Munster, Germany
| | - Meik Blanke
- Center for Nanointegration Duisburg-Essen (CENIDE), Faculty of Chemistry (Organic Chemistry), University of Duisburg-Essen, Universitätsstraße 7, D-45141 Essen, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany
| | - Oliver Maus
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany
| | - Dominik Schwab
- Center for Multiscale Theory and Computation, Institut für Festkörpertheorie, Universität Münster, Wilhelm-Klemm-Straße 10, D-48149 Münster, Germany
| | - Nikos L. Doltsinis
- Center for Multiscale Theory and Computation, Institut für Festkörpertheorie, Universität Münster, Wilhelm-Klemm-Straße 10, D-48149 Münster, Germany
| | - Wolfgang G. Zeier
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany
| | - Michael Giese
- Center for Nanointegration Duisburg-Essen (CENIDE), Faculty of Chemistry (Organic Chemistry), University of Duisburg-Essen, Universitätsstraße 7, D-45141 Essen, Germany
| | - Jens Voskuhl
- Center for Nanointegration Duisburg-Essen (CENIDE), Faculty of Chemistry (Organic Chemistry), University of Duisburg-Essen, Universitätsstraße 7, D-45141 Essen, Germany
| | - Cristian A. Strassert
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany
- Center of Nanotechnology (CeNTech), Center for Soft Nanosciences (SoN), Cells in Motion Interfaculty Cluster (CiMIC), Universität Münster, Heisenbergstraße 11, D-48149 Munster, Germany
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Korzun A, Crespi S, Golz C, Bismuto A. Replacing the BO in BODIPY: unlocking the path to SBDIPY and BIDIPY chromophores. Chem Sci 2023; 14:6579-6584. [PMID: 37350824 PMCID: PMC10284139 DOI: 10.1039/d3sc01493b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/28/2023] [Indexed: 06/24/2023] Open
Abstract
Boron-based dipyrrin chromophores (BODIPY) have found widespread application over the last twenty years in fields as diverse as medicine and materials. Thus, several efforts have been placed to exchange boron with other elements, with the aim of developing materials with complementary luminescent properties. However, despite these attempts, the incorporation of other main-group elements in dipyrrin scaffolds remains still rare. We have successfully synthesized and characterized novel chromophores based on antimony and bismuth, SBDIPY and BIDIPY. Solution stabilities have been investigated by VT-UV/vis spectroscopy and the fluorescence emission studied and supported by computational analysis. We were also able to isolate the first direct analogue of BODIPY containing fluoride handles, disclosing preliminary luminescent features.
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Affiliation(s)
- André Korzun
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen Tammannstr. 2 37077 Göttingen Germany
| | - Stefano Crespi
- Department of Chemistry - Ångström Laboratory Uppsala University Box 523, 751 20 Uppsala Sweden
| | - Christopher Golz
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen Tammannstr. 2 37077 Göttingen Germany
| | - Alessandro Bismuto
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen Tammannstr. 2 37077 Göttingen Germany
- Institut für Anorganische Chemie Gerhard-Domagk-Straße 1 53121 Bonn Germany
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Friedel J, Krause M, Jordan R, Maisuls I, Brünink D, Schwab D, Doltsinis NL, Strassert CA, Klein A. Triplet Emitting C^N^C Cyclometalated Dibenzo[c,h]Acridine Pt(II) Complexes. Molecules 2022; 27. [PMID: 36432153 DOI: 10.3390/molecules27228054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/11/2022] [Accepted: 11/15/2022] [Indexed: 11/22/2022] Open
Abstract
In a series of Pt(II) complexes [Pt(dba)(L)] containing the very rigid, dianionic, bis-cyclometalating, tridentate C^N^C2− heterocyclic ligand dba2− (H2dba = dibenzo[c,h]acridine), the coligand (ancillary ligand) L = dmso, PPh3, CNtBu and Me2Imd (N,N’-dimethylimidazolydene) was varied in order to improve its luminescence properties. Beginning with the previously reported dmso complex, we synthesized the PPh3, CNtBu and Me2Imd derivatives and characterized them by elemental analysis, 1H (and 31P) NMR spectroscopy and MS. Cyclic voltammetry showed partially reversible reduction waves ranging between −1.89 and −2.10 V and increasing along the series Me2Imd < dmso ≈ PPh3 < CNtBu. With irreversible oxidation waves ranging between 0.55 (L = Me2Imd) and 1.00 V (dmso), the electrochemical gaps range between 2.65 and 2.91 eV while increasing along the series Me2Imd < CNtBu < PPh3 < dmso. All four complexes show in part vibrationally structured long-wavelength absorption bands peaking at around 530 nm. TD-DFT calculated spectra agree quite well with the experimental spectra, with only a slight redshift. The photoluminescence spectra of all four compounds are very similar. In fluid solution at 298 K, they show broad, only partially structured bands, with maxima at around 590 nm, while in frozen glassy matrices at 77 K, slightly blue-shifted (~580 nm) bands with clear vibronic progressions were found. The photoluminescence quantum yields ΦL ranged between 0.04 and 0.24, at 298 K, and between 0.80 and 0.90 at 77 K. The lifetimes τ at 298 K ranged between 60 and 14040 ns in Ar-purged solutions and increased from 17 to 43 µs at 77 K. The TD-DFT calculated emission spectra are in excellent agreement with the experimental findings. In terms of high ΦL and long τ, the dmso and PPh3 complexes outperform the CNtBu and Me2Imd derivatives. This is remarkable in view of the higher ligand strength of Me2Imd, compared with all other coligands, as concluded from the electrochemical data.
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Krause M, Maisuls I, Buss S, Strassert CA, Winter A, Schubert US, Nair SS, Dietzek-Ivanšić B, Klein A. Photophysical Study on the Rigid Pt(II) Complex [Pt(naphen)(Cl)] (Hnaphen = Naphtho[1,2-b][1,10]Phenanthroline and Derivatives. Molecules 2022; 27:molecules27207022. [PMID: 36296617 PMCID: PMC9606891 DOI: 10.3390/molecules27207022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/05/2022] [Accepted: 10/10/2022] [Indexed: 11/16/2022] Open
Abstract
The electrochemistry and photophysics of the Pt(II) complexes [Pt(naphen)(X)] (Hnaphen = naphtho[1,2-b][1,10]phenanthroline, X = Cl or C≡CPh) containing the rigid tridentate C^N^N-coordinating pericyclic naphen ligand was studied alongside the complexes of the tetrahydro-derivative [Pt(thnaphen)(X)] (Hthnaphen = 5,6,8,9-tetrahydro-naphtho[1,2-b][1,10]phenanthroline) and the N^C^N-coordinated complex [Pt(bdq)(Cl)] (Hbdq = benzo[1,2-h:5,4-h’]diquinoline. The cyclic voltammetry showed reversible reductions for the C^N^N complexes, with markedly fewer negative potentials (around −1.6 V vs. ferrocene) for the complexes containing the naphen ligand compared with the thnaphen derivatives (around −1.9 V). With irreversible oxidations at around +0.3 V for all of the complexes, the naphen made a difference in the electrochemical gap of about 0.3 eV (1.9 vs. 2.2 eV) compared with thnaphen. The bdq complex was completely different, with an irreversible reduction at around −2 V caused by the N^C^N coordination pattern, which lacked a good electron acceptor such as the phenanthroline unit in the C^N^N ligand naphen. Long-wavelength UV-Vis absorption bands were found around 520 to 530 nm for the C^N^N complexes with the C≡CPh coligand and were red-shifted when compared with the Cl derivatives. The N^C^N-coordinated bdq complex was markedly blue-shifted (493 nm). The steady-state photoluminescence spectra showed poorly structured emission bands peaking at around 630 nm for the two naphen complexes and 570 nm for the thnaphen derivatives. The bdq complex showed a pronounced vibrational structure and an emission maximum at 586 nm. Assuming mixed 3LC/3MLCT excited states, the vibronic progression for the N^C^N bdq complex indicated a higher LC character than assumed for the C^N^N-coordinated naphen and thnaphen complexes. The blue-shift was a result of the different N^C^N vs. C^N^N coordination. The photoluminescence lifetimes and quantum yields ΦL massively increased from solutions at 298 K (0.06 to 0.24) to glassy frozen matrices at 77 K (0.80 to 0.95). The nanosecond time-resolved study on [Pt(naphen)(Cl)] showed a phosphorescence emission signal originating from the mixed 3LC/3MLCT with an emission lifetime of around 3 µs.
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Affiliation(s)
- Maren Krause
- University of Cologne, Faculty of Mathematics and Natural Sciences, Department of Chemistry, Institute for Inorganic Chemistry, Greinstrasse 6, 50939 Köln, Germany
| | - Iván Maisuls
- Westfälische Wilhelms-Universität Münster, Institut für Anorganische und Analytische Chemie, CeNTech, CiMIC, SoN, Heisenbergstr. 11, 48149 Münster, Germany
| | - Stefan Buss
- Westfälische Wilhelms-Universität Münster, Institut für Anorganische und Analytische Chemie, CeNTech, CiMIC, SoN, Heisenbergstr. 11, 48149 Münster, Germany
| | - Cristian A. Strassert
- Westfälische Wilhelms-Universität Münster, Institut für Anorganische und Analytische Chemie, CeNTech, CiMIC, SoN, Heisenbergstr. 11, 48149 Münster, Germany
| | - Andreas Winter
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstr. 10, 07743 Jena, Germany
- Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
| | - Ulrich S. Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstr. 10, 07743 Jena, Germany
- Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
| | - Shruthi S. Nair
- Institute for Physical Chemistry (IPC), Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
- Leibniz Institute for Photonic Technologies Jena (IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
| | - Benjamin Dietzek-Ivanšić
- Institute for Physical Chemistry (IPC), Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
- Leibniz Institute for Photonic Technologies Jena (IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
- Correspondence: (B.D.-I.); (A.K.); Tel.: +49-221-470-4006 (A.K.)
| | - Axel Klein
- University of Cologne, Faculty of Mathematics and Natural Sciences, Department of Chemistry, Institute for Inorganic Chemistry, Greinstrasse 6, 50939 Köln, Germany
- Correspondence: (B.D.-I.); (A.K.); Tel.: +49-221-470-4006 (A.K.)
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Maisuls I, Kirse TM, Hepp A, Kösters J, Wolcan E, Strassert CA. Rhenium(I) Complexes with Neutral Monodentate Coligands and Monoanionic 2-(1,2,4-Triazol-5-yl)pyridine-Based Chelators as Bidentate Luminophores with Tunable Color and Photosensitized Generation of 1O 2: An Integrated Case Study Involving Photophysics and Theory. Inorg Chem 2022; 61:13775-13791. [PMID: 35998339 DOI: 10.1021/acs.inorgchem.2c01572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this work, we describe the synthesis as well as structural, photophysical, and theoretical investigation of a new coordination chemical concept involving rhenium(I) complexes bearing monoanionic 1,2,4-triazolylpyridine-based bidentate chromophores. The X-ray diffractometric analysis of single crystals revealed particular packing features: the trifluoromethylated exemplar displayed two kinds of arrangements of the coordination centers, where the bidentate ligands at the edges of the unit cell are staggered parallel to each other, whereas those inside show antiparallel stacking with respect to the external ligands. On the other hand, the complexes bearing an adamantyl substituent yield a linear arrangement, where the bulky moiety of one luminophore points to the pyridine center of the adjacent ligand of the neighboring complex while including methanol molecules hydrogen-bonded to the triazolato unit. We observed that the photophysical properties of the complexes (photoexcited-state lifetimes, photoluminescence maxima and quantum yields) can be adjusted by tuning of the substitution pattern at the bidentate luminophore as well as by variation of the monodentate coligand. The photoluminescence spectra and photoexcited-state lifetimes of the crystalline phases were measured by phosphorescence lifetime micro(spectro)scopy. Interestingly, the vibrationally resolved emission spectra of the crystals closely resemble those of diluted frozen glassy matrixes at 77 K, in contrast with the broad bands observed in amorphous solids and in fluid solutions, where the charge-transfer character is enhanced. While the photoluminescence quantum yields (ΦL) reach up to 15%, the complexes are able to attain up to 55% efficiency regarding the photosensitization of 1O2 (ΦΔ), depending on the combination of luminophore and coligand. Theoretical calculations showed that the photoexcited triplet (T1) state has a metal-ligand-to-ligand charge-transfer character, where promotion to the excited electronic configuration shortens the Re(I)-N bond involving the bidentate triazolylpyridine while stretching the three fac-CO-Re(I) bonds as well as the linkage to the axial monodentate coligand. The calculated vertical (Evl) and 0-0 (E(0-0)) radiative transition energies are in very good agreement with the experimental values (Eexplum).
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Affiliation(s)
- Iván Maisuls
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, Münster D-48149, Germany.,CeNTech, CiMIC, SoN, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 11, Münster D-48149, Germany
| | - Thomas M Kirse
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, Münster D-48149, Germany.,CeNTech, CiMIC, SoN, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 11, Münster D-48149, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, Münster D-48149, Germany
| | - Jutta Kösters
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, Münster D-48149, Germany
| | - Ezequiel Wolcan
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, UNLP, CCT La Plata-CONICET), Diagonal 113 and 64, Sucursal 4, Casilla de Correo 16, La Plata B1906, Argentina
| | - Cristian A Strassert
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, Münster D-48149, Germany.,CeNTech, CiMIC, SoN, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 11, Münster D-48149, Germany
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9
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Gutierrez Suburu ME, Maisuls I, Kösters J, Strassert CA. Room-temperature luminescence from Pd(II) and Pt(II) complexes: from mechanochromic crystals to flexible polymer matrices. Dalton Trans 2022; 51:13342-13350. [PMID: 35983882 DOI: 10.1039/d2dt01693a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of Pd(II) (PdLOMe, PdLOHex) and Pt(II) (PtLOMe, PtLOHex) complexes bearing tetradentate ligands as dianionic luminophores were synthesized. Hence, the cyclometallating chelators were alternatively decorated with two n-hexyloxy (LOHex) or two methoxy (LOMe) moieties to promote crystallization and processability. The new compounds were unambiguously characterized by means of multiple NMR spectroscopies and mass spectrometry as well as by single crystal X-ray diffractometric analysis (PtLOMe and PdLOMe). Steady state and time-resolved photoluminescence spectroscopic studies were carried out in crystalline phases, in fluid solutions at room temperature, in frozen glassy matrices at 77 K and in a flexible polymeric matrix (PMMA). PtLOMe presents an intriguing mechanochromism resulting from the responsive metal-metal interactions involving adjacent monomeric units. Incorporation of the Pd(II) complexes into the polymeric matrix boosts their photophysical properties by stiffening of the coordination environment while reducing non-radiative deactivation pathways mediated by dissociative metal-centred states, which also become thermally inaccessible at 77 K.
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Affiliation(s)
- Matias E Gutierrez Suburu
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany. .,CeNTech, SoN, CiMIC, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 11, D-48149 Munster, Germany
| | - Iván Maisuls
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany. .,CeNTech, SoN, CiMIC, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 11, D-48149 Munster, Germany
| | - Jutta Kösters
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany.
| | - Cristian A Strassert
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany. .,CeNTech, SoN, CiMIC, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 11, D-48149 Munster, Germany
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10
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Maisuls I, Boisten F, Hebenbrock M, Alfke J, Schürmann L, Jasper-Peter B, Hepp A, Esselen M, Müller J, Strassert CA. Monoanionic C^N^N Luminophores and Monodentate C-Donor Co-Ligands for Phosphorescent Pt(II) Complexes: A Case Study Involving Their Photophysics and Cytotoxicity. Inorg Chem 2022; 61:9195-9204. [PMID: 35666659 DOI: 10.1021/acs.inorgchem.2c00753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A family of Pt(II) complexes bearing monoanionic C^N^N ligands as luminophoric units as well as a set of monodentate ligands derived from allenylidene and carbene species were synthesized and characterized in terms of structure and photophysical properties. In addition, we present the extraordinary molecular structure of a phosphorescent complex carrying an allenylidene ligand. Depending on the co-ligand, an effect can be observed in the photoluminescence lifetimes and quantum yields as well as in the radiative and radiation less deactivation rate constants. Their correlation with the substitution pattern was analyzed by comparing the photoluminescence in fluid solution at room temperature and in frozen glassy matrices at 77 K. Moreover, in order to gain a deeper understanding of the electronic states responsible for the optical properties, density functional theory calculations were performed. Finally, the cytotoxicity of the complexes was evaluated in vitro, showing that the cationic complexes exhibit strong effects at low micromolar concentrations. The calculated half-maximum effective concentrations (EC50 values) were 4 times lower in comparison to the established antitumor agent oxaliplatin. In contrast, the neutral species are less toxic, rendering them as potential bioimaging agents.
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Affiliation(s)
- Iván Maisuls
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, Münster 48149, Germany.,CeNTech, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 11, Münster 48149, Germany.,Cells in Motion Interfaculty Centre (CiMIC) and Center for Soft Nanoscience (SoN), Westfälische Wilhelms-Universität Münster, Corrensstraße 30, Münster 48149, Germany
| | - Felix Boisten
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, Münster 48149, Germany
| | - Marian Hebenbrock
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, Münster 48149, Germany
| | - Julian Alfke
- Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 45, Münster 48149, Germany
| | - Lina Schürmann
- Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 45, Münster 48149, Germany
| | - Beate Jasper-Peter
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, Münster 48149, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, Münster 48149, Germany
| | - Melanie Esselen
- Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 45, Münster 48149, Germany
| | - Jens Müller
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, Münster 48149, Germany.,Cells in Motion Interfaculty Centre (CiMIC) and Center for Soft Nanoscience (SoN), Westfälische Wilhelms-Universität Münster, Corrensstraße 30, Münster 48149, Germany
| | - Cristian A Strassert
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, Münster 48149, Germany.,CeNTech, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 11, Münster 48149, Germany.,Cells in Motion Interfaculty Centre (CiMIC) and Center for Soft Nanoscience (SoN), Westfälische Wilhelms-Universität Münster, Corrensstraße 30, Münster 48149, Germany
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11
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Maisuls I, Singh J, Salto IP, Steiner ST, Kirse TM, Niemann S, Strassert CA, Faust A. Conjugated Pt(II) Complexes as Luminescence-Switch-On Reporters Addressing the Microenvironment of Bacterial Biofilms. Inorg Chem 2021; 60:11058-11069. [PMID: 34255500 DOI: 10.1021/acs.inorgchem.1c00860] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work, the synthesis, structural and photophysical characterization of six phosphorescent H2O-soluble Pt(II) complexes are reported while addressing their emission maxima, photoluminescence quantum yields (ΦL), lifetimes (τ), aggregation tendency, and microenvironment sensitivity as a function of the substitution pattern on the main tridentate luminophore. Different ancillary ligands, namely, a trisulfonated phosphane and maltohexaose-conjugated pyridines (with or without amide bridges), were introduced and evaluated for the realization of switch-on-photoluminescent labels reporting on the microenvironment sensed in biofilms of Gram+ and Gram- models, namely, Staphylococcus aureus and Escherichia coli. With the aid of confocal luminescence micro(spectro)scopy, we observed that selected complexes specifically interact with the biofilms while leaving planktonic cells unlabeled. By using photoluminescence lifetime imaging microscopy, excited-state lifetimes within S. aureus biofilms were measured. The photoluminescence intensities were drastically boosted, and the excited state lifetimes were significantly prolonged upon binding to the viscous biofilm matrix, mainly due to the suppression of radiationless deactivation pathways upon shielding from physical quenching processes, such as interactions with solvent molecules and 3O2. The best performances were attained for non-aggregating complexes with maltohexaose targeting units and without amide bridges. Notably, in the absence of the maltodextrin, a hydrophobic adamantyl moiety suffices to attain a sizeable labeling capacity. Moreover, photoluminescence studies showed that selected complexes can also effectively interact with E. coli biofilms, where the bacterial cells are able to partially uptake the maltodextrin-based agents. In summary, the herein introduced concepts enable the development of specific biofilm reporters providing spatial resolution as well as lifetime- and spectrum-based readouts. Considering that most theragnostic agents reported so far mainly address metabolically active bacteria at the surface of biofilms but without reaching cells deeply immersed in the matrix, a new platform with a clear structure-property correlation is provided for the early detection of such bacterial arrays.
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Affiliation(s)
- Iván Maisuls
- Institut für Anorganische und Analytische Chemie, CiMiC, SoN and CeNTech, Wesfälische Wilhelms-Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Jasveer Singh
- Institut für Anorganische und Analytische Chemie, CiMiC, SoN and CeNTech, Wesfälische Wilhelms-Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Ileana P Salto
- Institute of Medical Microbiology, University Hospital Münster, Domagkstr. 10, 48149 Münster, Germany
| | - Simon T Steiner
- European Institute for Molecular Imaging, University of Münster, Münster, Waldeyerstr. 15, 48159 Münster, Germany
| | - Thomas M Kirse
- Institut für Anorganische und Analytische Chemie, CiMiC, SoN and CeNTech, Wesfälische Wilhelms-Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Silke Niemann
- Institute of Medical Microbiology, University Hospital Münster, Domagkstr. 10, 48149 Münster, Germany.,Interdisciplinary Center of Clinical Research (IZKF), University Hospital Münster, 48149 Münster, Germany
| | - Cristian A Strassert
- Institut für Anorganische und Analytische Chemie, CiMiC, SoN and CeNTech, Wesfälische Wilhelms-Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Andreas Faust
- European Institute for Molecular Imaging, University of Münster, Münster, Waldeyerstr. 15, 48159 Münster, Germany.,Interdisciplinary Center of Clinical Research (IZKF), University Hospital Münster, 48149 Münster, Germany
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Kumar S, Balakrishna MS. Transition metal complexes of imidazole appended pyridyline linked bisphosphine, 2,6-bis(2-(diphenylphosphanyl)-1H-imidazol-1-yl)pyridine. Results in Chemistry 2021; 3:100161. [DOI: 10.1016/j.rechem.2021.100161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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