1
|
Lin Z, Zhou Q, Liu Y, Chen C, Jie J, Su H. Multiphoton tandem photoredox catalysis of [Ir(dFCF 3ppy) 2(dtbbpy)] + facilitating radical acylation reactions. Chem Sci 2024; 15:11919-11927. [PMID: 39092118 PMCID: PMC11290445 DOI: 10.1039/d4sc03183k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Accepted: 06/26/2024] [Indexed: 08/04/2024] Open
Abstract
Photoredox catalytic radical acylation reactions, utilizing [Ir(dFCF3ppy)2(dtbbpy)]+ (IrIII) as the photocatalyst and α-keto acids as the starting substrates, have recently emerged as an attractive strategy for preparing ketone derivatives. While there is consensus on the importance of detailed mechanistic insights to maximize the formation of desired products, efforts focused on uncovering the underlying elementary mechanisms of IrIII photocatalytic radical acylation reactions are still lacking. Herein, using time-resolved spectroscopy, we observed the efficient quenching of the triplet state, 3IrIII*, via electron transfer from α-keto acids, resulting in the generatation of the reduced IrII. Subsequently, IrII rapidly transforms into a stable IrH+ species through protonation, with α-keto acid acting as a proton donor. Upon absorbing additional photon(s), IrH+ is expected to transform into IrH3, involving further hydrogenation/protonation. Emission and Fourier transform infrared (FTIR) spectroscopy, together with global analysis, identify the character of IrH3/3IrH3* and corroborate its contribution to representative radical acylation reactions (decarboxylative 1,4-addition of α-keto acids with Michael acceptors, decarboxylative coupling of α-keto acids with aryl halides, and decarboxylative cyclization of 2-alkenylarylisocyanides with α-keto acids), where IrH3/3IrH3* serves as the key species to trigger the second photoredox cycle. These results elucidate the existence and generality of the tandem photoredox catalysis mechanism for IrIII photocatalytic radical acylation reactions, providing advanced insights into the mechanism of IrIII-based photoredox processes and potentially expanding their application in the design and development of new synthetic methodologies.
Collapse
Affiliation(s)
- Zhicong Lin
- College of Chemistry, Beijing Normal University Beijing 100875 China
| | - Qian Zhou
- College of Chemistry, Beijing Normal University Beijing 100875 China
| | - Yan Liu
- College of Chemistry, Beijing Normal University Beijing 100875 China
| | - Chenli Chen
- College of Chemistry, Beijing Normal University Beijing 100875 China
| | - Jialong Jie
- College of Chemistry, Beijing Normal University Beijing 100875 China
| | - Hongmei Su
- College of Chemistry, Beijing Normal University Beijing 100875 China
| |
Collapse
|
2
|
Gonzalo-Navarro C, Zafon E, Organero JA, Jalón FA, Lima JC, Espino G, Rodríguez AM, Santos L, Moro AJ, Barrabés S, Castro J, Camacho-Aguayo J, Massaguer A, Manzano BR, Durá G. Ir(III) Half-Sandwich Photosensitizers with a π-Expansive Ligand for Efficient Anticancer Photodynamic Therapy. J Med Chem 2024; 67:1783-1811. [PMID: 38291666 PMCID: PMC10859961 DOI: 10.1021/acs.jmedchem.3c01276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 12/12/2023] [Accepted: 01/11/2024] [Indexed: 02/01/2024]
Abstract
One approach to reduce the side effects of chemotherapy in cancer treatment is photodynamic therapy (PDT), which allows spatiotemporal control of the cytotoxicity. We have used the strategy of coordinating π-expansive ligands to increase the excited state lifetimes of Ir(III) half-sandwich complexes in order to facilitate the generation of 1O2. We have obtained derivatives of formulas [Cp*Ir(C∧N)Cl] and [Cp*Ir(C∧N)L]BF4 with different degrees of π-expansion in the C∧N ligands. Complexes with the more π-expansive ligand are very effective photosensitizers with phototoxic indexes PI > 2000. Furthermore, PI values of 63 were achieved with red light. Time-dependent density functional theory (TD-DFT) calculations nicely explain the effect of the π-expansion. The complexes produce reactive oxygen species (ROS) at the cellular level, causing mitochondrial membrane depolarization, cleavage of DNA, nicotinamide adenine dinucleotide (NADH) oxidation, as well as lysosomal damage. Consequently, cell death by apoptosis and secondary necrosis is activated. Thus, we describe the first class of half-sandwich iridium cyclometalated complexes active in PDT.
Collapse
Affiliation(s)
- Carlos Gonzalo-Navarro
- Departamento
de Química Inorgánica, Orgánica y Bioquímica-
IRICA, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. C. J. Cela, 10, 13071 Ciudad Real, Spain
| | - Elisenda Zafon
- Departament
de Biologia, Facultat de Ciències, Universitat de Girona, Maria Aurèlia Capmany 40, 17003 Girona, Spain
| | - Juan Angel Organero
- Departamento
de Química Física, Facultad de Ciencias Ambientales
y Bioquímicas and INAMOL, Universidad
de Castilla-La Mancha, 45071 Toledo, Spain
| | - Félix A. Jalón
- Departamento
de Química Inorgánica, Orgánica y Bioquímica-
IRICA, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. C. J. Cela, 10, 13071 Ciudad Real, Spain
| | - Joao Carlos Lima
- LAQV-REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Gustavo Espino
- Departamento
de Química, Facultad de Ciencias, Universidad de Burgos, Pza. Misael Bañuelos, s/n, 09001 Burgos, Spain
| | - Ana María Rodríguez
- Departamento
de Química Inorgánica, Orgánica y Bioquímica-
IRICA, Escuela Técnica Superior de Ingenieros Industriales, Universidad de Castilla-La Mancha, Avda. C. J. Cela, 3, 13071 Ciudad Real, Spain
| | - Lucía Santos
- Departamento
de Química Física, Facultad de Ciencias y Tecnologías
Químicas, Universidad de Castilla-La
Mancha, Avda. C. J. Cela,
s/n, 13071 Ciudad
Real, Spain
| | - Artur J. Moro
- LAQV-REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Sílvia Barrabés
- Departament
de Biologia, Facultat de Ciències, Universitat de Girona, Maria Aurèlia Capmany 40, 17003 Girona, Spain
| | - Jessica Castro
- Departament
de Biologia, Facultat de Ciències, Universitat de Girona, Maria Aurèlia Capmany 40, 17003 Girona, Spain
| | - Javier Camacho-Aguayo
- Analytical
Chemistry Department, Analytic Biosensors Group, Instituto de Nanociencia
y Nanomateriales de Aragon, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza, Spain
| | - Anna Massaguer
- Departament
de Biologia, Facultat de Ciències, Universitat de Girona, Maria Aurèlia Capmany 40, 17003 Girona, Spain
| | - Blanca R. Manzano
- Departamento
de Química Inorgánica, Orgánica y Bioquímica-
IRICA, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. C. J. Cela, 10, 13071 Ciudad Real, Spain
| | - Gema Durá
- Departamento
de Química Inorgánica, Orgánica y Bioquímica-
IRICA, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. C. J. Cela, 10, 13071 Ciudad Real, Spain
| |
Collapse
|
3
|
Di Girolamo A, Monti F, Mazzanti A, Matteucci E, Armaroli N, Sambri L, Baschieri A. 4-Phenyl-1,2,3-triazoles as Versatile Ligands for Cationic Cyclometalated Iridium(III) Complexes. Inorg Chem 2022; 61:8509-8520. [PMID: 35609179 PMCID: PMC9490865 DOI: 10.1021/acs.inorgchem.2c00567] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
![]()
Five cationic iridium(III)
complexes (1–5) were synthesized
exploiting two triazole-based cyclometalating
ligands, namely, 1-methyl-4-phenyl-1H-1,2,3-triazole
(A) and the corresponding mesoionic carbene 1,3-dimethyl-4-phenyl-1H-1,2,3-triazol-5-ylidene (B). From the combination
of these two ligands and the ancillary one, i.e., 4,4′-di-tert-butyl-2,2′-bipyridine (for 1–3) or tert-butyl isocyanide (for 4 and 5), not only the typical bis-heteroleptic complexes
but also the much less explored tris-heteroleptic analogues (2 and 5) could be synthesized. The redox and
emission properties of all of the complexes are effectively fine-tuned
by the different ligands: (i) cyclometalating ligand A induces a stronger highest occupied molecular orbital (HOMO) stabilization
compared to B and leads to complexes with progressively
narrower HOMO–lowest unoccupied molecular orbital (LUMO) and
redox gaps, and lower emission energy; (ii) complexes 1–3, equipped with the bipyridine ancillary ligand,
display fully reversible redox processes and emit from predominantly
metal-to-ligand charge transfer (MLCT) states with high emission quantum
yields, up to 60% in polymeric matrix; (iii) complexes 4 and 5, equipped with high-field isocyanide ligands,
display irreversible redox processes and high-energy emission from
strongly ligand-centered triplets with long emission lifetimes but
relatively low quantum yields (below 6%, both in room-temperature
solution and in solid state). This work demonstrates the versatility
of phenyl-triazole derivatives as cyclometalating ligands with different
chelation modes (i.e., C∧N and C∧C:) for the synthesis of photoactive iridium(III) complexes with
highly tunable properties. Triazole-based
cyclometalating ligands serving as both standard
C∧N chelators (as in 4-phenyl-triazole) and C∧C: carbene ones (as in 4-phenyl-triazolylidene) have
been used to synthesize a series of cationic iridium(III) complexes.
Accordingly, unusual tris-heteroleptic complexes could be obtained
by simultaneously exploiting both chelation modes. These ligands allow
fine tuning of the properties of the related complexes, which exhibit
luminescence all the way from blue to red and quantum yields up to
60% in a diluted polymeric matrix at 298 K.
Collapse
Affiliation(s)
- Alessandro Di Girolamo
- Department of Industrial Chemistry "Toso Montanari", University of Bologna, Bologna 40136, Italy
| | - Filippo Monti
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche (ISOF-CNR), Bologna 40129, Italy
| | - Andrea Mazzanti
- Department of Industrial Chemistry "Toso Montanari", University of Bologna, Bologna 40136, Italy
| | - Elia Matteucci
- Department of Industrial Chemistry "Toso Montanari", University of Bologna, Bologna 40136, Italy
| | - Nicola Armaroli
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche (ISOF-CNR), Bologna 40129, Italy
| | - Letizia Sambri
- Department of Industrial Chemistry "Toso Montanari", University of Bologna, Bologna 40136, Italy
| | - Andrea Baschieri
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche (ISOF-CNR), Bologna 40129, Italy
| |
Collapse
|
4
|
Ion-pair reorganization regulates reactivity in photoredox catalysts. Nat Chem 2022; 14:746-753. [DOI: 10.1038/s41557-022-00911-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 02/17/2022] [Indexed: 11/08/2022]
|
5
|
Yiu SC, Ho PY, Kwok YY, He X, Wang Y, Yu WH, Ho CL, Huang S. Development of Strong Visible-Light-Absorbing Cyclometalated Iridium(III) Complexes for Robust and Efficient Light-Driven Hydrogen Production. Chemistry 2022; 28:e202104575. [PMID: 35170133 DOI: 10.1002/chem.202104575] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Indexed: 12/12/2022]
Abstract
Weak light absorption of common Ir(III) complexes (e. g., using phenylpyridine as the ligand) has hindered their applications in photocatalytic hydrogen generation from water as an efficient photosensitizer. To address this issue, a series of cyclometalated Ir(III) complexes (Ir1-Ir5), featuring different electron-donating substituents to enhance the absorptivity, have been synthesized and studied as photosensitizers (PSs) for light-driven hydrogen production from water. Ir6-Ir7 were prepared as fundamental systems for comparisons. Electron donors, including 9-phenylcarbazole, triphenylamine, 4,4'-dimethoxytriphenylamine, 4,4'-di(N-hexylcarbazole)triphenylamine moieties were introduced on 6-(thiophen-2-yl)phenanthridine-based cyclometalating (C^N) ligands to explore the donor effect on the hydrogen evolution performance of these cationic Ir(III) complexes. Remarkably, Ir4 with 4,4'-dimethoxytriphenylamine achieved the highest turn-over number (TON) of 12 300 and initial turnover frequency (TOFi ) of 394 h-1 , with initial activity (activityi ) of 547 000 μmol g-1 h-1 and initial apparent quantum yield (AQYi ) of 9.59 %, under the illumination of blue light-emitting diodes (LEDs) for 105 hours, which demonstrated a stable three-component photocatalytic system with high efficiency. The TON (based on n(H2 )/n(PSr)) in this study is the highest value reported to date among the similar photocatalytic systems using Ir(III) complexes with Pt nanoparticles as catalyst. The great potential of using triphenylamine-based Ir(III) PSs in boosting photocatalytic performance has also been shown.
Collapse
Affiliation(s)
- Sze-Chun Yiu
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hung Hom, Hong Kong, P. R. China.,PolyU Shenzhen Research Institute, Shenzhen, P. R. China.,Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Hong Kong, P. R. China
| | - Po-Yu Ho
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hung Hom, Hong Kong, P. R. China.,PolyU Shenzhen Research Institute, Shenzhen, P. R. China.,Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Hong Kong, P. R. China.,Biological Inorganic Chemistry Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, United Kingdom.,Department of Chemistry, King's College London Britannia House, 7 Trinity Street, London, SE1 1DB, United Kingdom
| | - Yan-Yi Kwok
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hung Hom, Hong Kong, P. R. China.,PolyU Shenzhen Research Institute, Shenzhen, P. R. China
| | - Xiaojie He
- College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China
| | - Yi Wang
- Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Hong Kong, P. R. China
| | - Wai-Hong Yu
- Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Hong Kong, P. R. China
| | - Cheuk-Lam Ho
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hung Hom, Hong Kong, P. R. China.,PolyU Shenzhen Research Institute, Shenzhen, P. R. China.,Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Hong Kong, P. R. China
| | - Shuping Huang
- College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China
| |
Collapse
|
6
|
Visible light-driven efficient palladium catalyst turnover in oxidative transformations within confined frameworks. Nat Commun 2022; 13:928. [PMID: 35177599 PMCID: PMC8854557 DOI: 10.1038/s41467-022-28474-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 01/07/2022] [Indexed: 11/08/2022] Open
Abstract
Palladium catalyst turnover by reoxidation of a low-valent Pd species dominates the proceeding of an efficient oxidative transformation, but the state-of-the-art catalysis approaches still have great challenges from the perspectives of high efficiency, atom-economy and environmental-friendliness. Herein, we report a new strategy for addressing Pd reoxidation problem by the fabrication of spatially proximate IrIII photocatalyst and PdII catalyst into metal-organic framework (MOF), affording MOFs based Pd/photoredox catalysts UiO-67-Ir-PdX2 (X = OAc, TFA), which are systematically evaluated using three representative Pd-catalyzed oxidation reactions. Owing to the stabilization of single-site Pd and Ir catalysts by MOFs framework as well as the proximity of them favoring fast electron transfer, UiO-67-Ir-PdX2, under visible light, exhibits up to 25 times of Pd catalyst turnover number than the existing catalysis systems. Mechanism investigations theoretically corroborate the capability of MOFs based Pd/photoredox catalysis to regulate the competitive processes of Pd0 aggregation and reoxidation in Pd-catalyzed oxidation reactions.
Collapse
|
7
|
Hüttenschmidt M, Lange H, Cordero MAA, Villinger A, Lochbrunner S, Seidel WW. Development and application of redox-active cyclometallating ligands based on W(II) alkyne complexes. Dalton Trans 2022; 51:852-856. [PMID: 35006216 DOI: 10.1039/d1dt02393d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The assembly of dinuclear complexes with the ultimate smallest ditopic ligands based on side-on complexes of methyl substituted alkynes is presented. In fact, the coordination of Ru(II) and Ir(III) by a W alkyne complex based cyclometallating metalla-ligand causes close intermetallic electronic cooperation, which substantially changes the electrochemical and photophysical properties of the single isolated moieties.
Collapse
Affiliation(s)
| | - Helge Lange
- Institut für Chemie, Universität Rostock, 18055 Rostock, Germany.
| | | | | | - Stefan Lochbrunner
- Institute for Physics and Department of Life, Light and Matter, Universität Rostock, 18051 Rostock, Germany
| | - Wolfram W Seidel
- Institut für Chemie, Universität Rostock, 18055 Rostock, Germany. .,Leibniz-Institut für Katalyse e.V., 18059 Rostock, Germany
| |
Collapse
|
8
|
Kim S, Choi J, Cho DW, Ahn M, Eom S, Kim J, Wee KR, Ihee H. Solvent-modulated proton-coupled electron transfer in an iridium complex with an ESIPT ligand. Chem Sci 2022; 13:3809-3818. [PMID: 35432886 PMCID: PMC8966730 DOI: 10.1039/d1sc07250a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/03/2022] [Indexed: 11/21/2022] Open
Abstract
Proton-coupled electron transfer (PCET), an essential process in nature with a well-known example of photosynthesis, has recently been employed in metal complexes to improve the energy conversion efficiency; however, a profound understanding of the mechanism of PCET in metal complexes is still lacking. In this study, we synthesized cyclometalated Ir complexes strategically designed to exploit the excited-state intramolecular proton transfer (ESIPT) of the ancillary ligand and studied their photoinduced PCET in both aprotic and protic solvent environments using femtosecond transient absorption spectroscopy and density functional theory (DFT) and time-dependent DFT calculations. The data reveal solvent-modulated PCET, where charge transfer follows proton transfer in an aprotic solvent and the temporal order of charge transfer and proton transfer is reversed in a protic solvent. In the former case, ESIPT from the enol form to the keto form, which precedes the charge transfer from Ir to the ESIPT ligand, improves the efficiency of metal-to-ligand charge transfer. This finding demonstrates the potential to control the PCET reaction in the desired direction and the efficiency of charge transfer by simply perturbing the external hydrogen-bonding network with the solvent. The iridium complex with an ESIPT ligand shows solvent-modulated proton-coupled electron transfer, in which the temporal order of proton transfer and charge transfer is altered by the solvent environment.![]()
Collapse
Affiliation(s)
- Siin Kim
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science Daejeon 34141 Republic of Korea
| | - Jungkweon Choi
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science Daejeon 34141 Republic of Korea
| | - Dae Won Cho
- Department of Advanced Materials Chemistry, Korea University, Sejong Campus Sejong 30019 Korea
| | - Mina Ahn
- Department of Chemistry and Institute of Natural Science, Daegu University Gyeongsan 38453 Republic of Korea
| | - Seunghwan Eom
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science Daejeon 34141 Republic of Korea
| | - Jungmin Kim
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science Daejeon 34141 Republic of Korea
| | - Kyung-Ryang Wee
- Department of Chemistry and Institute of Natural Science, Daegu University Gyeongsan 38453 Republic of Korea
| | - Hyotcherl Ihee
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science Daejeon 34141 Republic of Korea
| |
Collapse
|
9
|
Smortsova Y, Falaise C, Fatima A, Ha-Thi MH, Méallet-Renault R, Steenkeste K, Al-Bacha S, Chaib T, Assaud L, Lepeltier M, Haouas M, Leclerc N, Pino T, Cadot E. Time-Resolved Spectroscopy and High-Efficiency Light-Driven Hydrogen Evolution of a {Mo 3 S 4 }-Containing Polyoxometalate-Based System. Chemistry 2021; 27:17094-17103. [PMID: 34590748 DOI: 10.1002/chem.202102693] [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: 07/23/2021] [Indexed: 11/05/2022]
Abstract
Polyoxothiometalate ions (ThioPOM) are active hydrogen-evolution reaction (HER) catalysts based on modular assembly built from electrophilic clusters {MoSx } and vacant polyoxotungstates. Herein, the dumbbell-like anion [{(PW11 O39 )Mo3 S4 (H2 O)3 (OH)}2 ]8- exhibits very high light-driven HER activity, while the active cores {Mo3 S4 } do not contain any exposed disulfido ligands, which were suspected to be the origin of the HER activity. Moreover, in the catalyst architecture, the two central {Mo3 S4 } cores are sandwiched by two {PW11 O39 }7- subunits that act as oxidant-resistant protecting groups and behave as electron-collecting units. A detailed photophysical study was carried out confirming the reductive quenching mechanism of the photosensitizer [Ir(ppy)2 (dtbbpy)]+ by the sacrificial donor triethanolamine (TEOA) and highlighting the very high rate constant of the electron transfer from the reduced photosensitizer to the ThioPOM catalyst. Such results provide new insights into the field of molecular catalytic systems able to promote high HER activity.
Collapse
Affiliation(s)
- Yevheniia Smortsova
- ILV-CNRS UMR 8180, UVSQ, Université Paris-Saclay, 45, Avenue des Etats Unis, 78035, Versailles Cedex, France
| | - Clément Falaise
- ILV-CNRS UMR 8180, UVSQ, Université Paris-Saclay, 45, Avenue des Etats Unis, 78035, Versailles Cedex, France
| | - Anam Fatima
- ISMO-CNRS UMR 8214, Université Paris-Saclay, Rue André Rivière, 91400, Orsay, France
| | - Minh-Huong Ha-Thi
- ISMO-CNRS UMR 8214, Université Paris-Saclay, Rue André Rivière, 91400, Orsay, France
| | | | - Karine Steenkeste
- ISMO-CNRS UMR 8214, Université Paris-Saclay, Rue André Rivière, 91400, Orsay, France
| | - Serge Al-Bacha
- ICMMO-CNRS UMR 8182, Université Paris-Saclay, Rue du Doyen Georges Poitou, 91400, Orsay, France
| | - Tesnim Chaib
- ILV-CNRS UMR 8180, UVSQ, Université Paris-Saclay, 45, Avenue des Etats Unis, 78035, Versailles Cedex, France
| | - Loïc Assaud
- ICMMO-CNRS UMR 8182, Université Paris-Saclay, Rue du Doyen Georges Poitou, 91400, Orsay, France
| | - Marc Lepeltier
- ILV-CNRS UMR 8180, UVSQ, Université Paris-Saclay, 45, Avenue des Etats Unis, 78035, Versailles Cedex, France
| | - Mohamed Haouas
- ILV-CNRS UMR 8180, UVSQ, Université Paris-Saclay, 45, Avenue des Etats Unis, 78035, Versailles Cedex, France
| | - Nathalie Leclerc
- ILV-CNRS UMR 8180, UVSQ, Université Paris-Saclay, 45, Avenue des Etats Unis, 78035, Versailles Cedex, France
| | - Thomas Pino
- ISMO-CNRS UMR 8214, Université Paris-Saclay, Rue André Rivière, 91400, Orsay, France
| | - Emmanuel Cadot
- ILV-CNRS UMR 8180, UVSQ, Université Paris-Saclay, 45, Avenue des Etats Unis, 78035, Versailles Cedex, France
| |
Collapse
|
10
|
Sayre H, Ripberger HH, Odella E, Zieleniewska A, Heredia DA, Rumbles G, Scholes GD, Moore TA, Moore AL, Knowles RR. PCET-Based Ligand Limits Charge Recombination with an Ir(III) Photoredox Catalyst. J Am Chem Soc 2021; 143:13034-13043. [PMID: 34378919 DOI: 10.1021/jacs.1c01701] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Upon photoinitiated electron transfer, charge recombination limits the quantum yield of photoredox reactions for which the rates for the forward reaction and back electron transfer are competitive. Taking inspiration from a proton-coupled electron transfer (PCET) process in Photosystem II, a benzimidazole-phenol (BIP) has been covalently attached to the 2,2'-bipyridyl ligand of [Ir(dF(CF3)ppy)2(bpy)][PF6] (dF(CF3)ppy = 2-(2,4-difluorophenyl)-5-(trifluoromethyl)pyridine; bpy = 2,2'-bipyridyl). Excitation of the [Ir(dF(CF3)ppy)2(BIP-bpy)][PF6] photocatalyst results in intramolecular PCET to form a charge-separated state with oxidized BIP. Subsequent reduction of methyl viologen dication (MV2+), a substrate surrogate, by the reducing moiety of the charge separated species demonstrates that the inclusion of BIP significantly slows the charge recombination rate. The effect of ∼24-fold slower charge recombination in a photocatalytic phthalimide ester reduction resulted in a greater than 2-fold increase in reaction quantum efficiency.
Collapse
Affiliation(s)
- Hannah Sayre
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Hunter H Ripberger
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Emmanuel Odella
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Anna Zieleniewska
- National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Daniel A Heredia
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Garry Rumbles
- National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Gregory D Scholes
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Thomas A Moore
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Ana L Moore
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Robert R Knowles
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| |
Collapse
|
11
|
Two Excited State Collaboration of Heteroleptic Ir(III)-Coumarin Complexes for H2 Evolution Dye-Sensitized Photocatalysts. ENERGIES 2021. [DOI: 10.3390/en14092425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Interfacial electron injection from a photoexcited surface-immobilized dye to a semiconductor substrate is a key reaction for dye-sensitized photocatalysts. We previously reported that the molecular orientation of heteroleptic Ir(III) photosensitizer on the TiO2 nanoparticle surface was important for efficient interfacial electron injection. In this work, to overcome the weak light absorption ability of heteroleptic Ir(III) photosensitizer and to improve the photoinduced charge-separation efficiency at the dye–semiconductor interface, we synthesized two heteroleptic Ir(III) complexes with different coumarin dyes, [Ir(C6)2(H4CPbpy)]Cl and [Ir(C30)2(H4CPbpy)]Cl [Ir-CX; X = 6 or 30; HC6 = 3-(2-enzothiazolyl)-7-(diethylamino)coumarin, HC30 = 3-(2-N-methylbenzimidazolyl)-7-N,N-diethylaminocoumarin, H4CPbpy = 4,4′-bis(methylphosphonic acid)-2,2′-bipyridine], as the cyclometalated ligands and immobilized them on the surface of Pt-cocatalyst-loaded TiO2 nanoparticles. Ultraviolet-visible absorption and emission spectroscopy revealed that the singlet ligand-centered (1LC) absorption and triplet 3LC emission bands of Ir-C30 occurred at shorter wavelengths than those of Ir-C6, while time-dependent density-functional-theory data suggested that the ligand-to-ligand charge transfer (LLCT) excited states of the two complexes were comparable. The photocatalytic H2 evolution activity of the Ir-C6-sensitized Pt-TiO2 nanoparticles (Ir-C6@Pt-TiO2) under visible light irradiation (λ > 420 nm) was higher than that of Ir-C30@Pt-TiO2. In contrast, their activities were comparable under irradiation with monochromatic light (λ = 450 ± 10 nm), which is absorbed comparably by both Ir-CX complexes. These results suggest that the internal conversion from the higher-lying LC state to the LLCT state effectively occurs in both Ir-CX complexes to trigger electron injection to TiO2.
Collapse
|
12
|
Daubit IM, Wortmann S, Siegmund D, Hahn S, Nuernberger P, Metzler‐Nolte N. Unveiling Luminescent Ir I and Rh I N-Heterocyclic Carbene Complexes: Structure, Photophysical Specifics, and Cellular Localization in the Endoplasmic Reticulum. Chemistry 2021; 27:6783-6794. [PMID: 33755263 PMCID: PMC8252781 DOI: 10.1002/chem.202100375] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Indexed: 01/28/2023]
Abstract
Complexes of RhI and IrI of the [M(COD)(NHC)X] type (where M=Rh or Ir, COD=1,5-cyclooctadiene, NHC=N-heterocyclic carbene, and X=halide) have recently shown promising cytotoxic activities against several cancer cell lines. Initial mechanism of action studies provided some knowledge about their interaction with DNA and proteins. However, information about their cellular localization remains scarce owing to luminescence quenching within this complex type. Herein, the synthesis of two rare examples of luminescent RhI and IrI [M(COD)(NHC)I] complexes with 1,8-naphthalimide-based emitting ligands is reported. All new complexes are comprehensively characterized, including with single-crystal X-ray structures. Steric crowding in one derivative leads to two distinct rotamers in solution, which apparently can be distinguished both by pronounced NMR shifts and by their respective spectral and temporal emission signatures. When the photophysical properties of these new complexes are exploited for cellular imaging in HT-29 and PT-45 cancer cell lines, it is demonstrated that the complexes accumulate predominantly in the endoplasmic reticulum, which is an entirely new finding and provides the first insight into the cellular localization of such IrI (NHC) complexes.
Collapse
Affiliation(s)
- Isabelle Marie Daubit
- Faculty of Chemistry and BiochemistryInorganic Chemistry I—Bioinorganic ChemistryRuhr-Universität BochumUniversitätsstraße 15044780BochumGermany
| | - Svenja Wortmann
- Institut für Physikalische und Theoretische ChemieUniversität RegensburgUniversitätsstraße 3193053RegensburgGermany
| | - Daniel Siegmund
- Division EnergyFraunhofer UMSICHTOsterfelder Str. 346047OberhausenGermany
| | - Stephan Hahn
- Molecular GI OncologyRuhr-Universität BochumUniversitätsstraße 15044780BochumGermany
| | - Patrick Nuernberger
- Institut für Physikalische und Theoretische ChemieUniversität RegensburgUniversitätsstraße 3193053RegensburgGermany
| | - Nils Metzler‐Nolte
- Faculty of Chemistry and BiochemistryInorganic Chemistry I—Bioinorganic ChemistryRuhr-Universität BochumUniversitätsstraße 15044780BochumGermany
| |
Collapse
|
13
|
Britz A, Bokarev SI, Assefa TA, Bajnóczi ÈG, Németh Z, Vankó G, Rockstroh N, Junge H, Beller M, Doumy G, March AM, Southworth SH, Lochbrunner S, Kühn O, Bressler C, Gawelda W. Site-Selective Real-Time Observation of Bimolecular Electron Transfer in a Photocatalytic System Using L-Edge X-Ray Absorption Spectroscopy*. Chemphyschem 2021; 22:693-700. [PMID: 33410580 PMCID: PMC8048488 DOI: 10.1002/cphc.202000845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/21/2020] [Indexed: 12/19/2022]
Abstract
Time-resolved X-ray absorption spectroscopy has been utilized to monitor the bimolecular electron transfer in a photocatalytic water splitting system. This has been possible by uniting the local probe and element specific character of X-ray transitions with insights from high-level ab initio calculations. The specific target has been a heteroleptic [IrIII (ppy)2 (bpy)]+ photosensitizer, in combination with triethylamine as a sacrificial reductant and Fe 3 ( CO ) 12 as a water reduction catalyst. The relevant molecular transitions have been characterized via high-resolution Ir L-edge X-ray absorption spectroscopy on the picosecond time scale and restricted active space self-consistent field calculations. The presented methods and results will enhance our understanding of functionally relevant bimolecular electron transfer reactions and thus will pave the road to rational optimization of photocatalytic performance.
Collapse
Affiliation(s)
- Alexander Britz
- European XFELHolzkoppel 422869SchenefeldGermany
- The Hamburg Centre for Ultrafast ImagingLuruper Chaussee 14922761HamburgGermany
- Department of Experimental Physics, Universität HamburgJungiusstraße 920355HamburgGermany
| | - Sergey I. Bokarev
- Institut für PhysikUniversität RostockAlbert-Einstein-Str. 23–2418059RostockGermany
| | - Tadesse A. Assefa
- European XFELHolzkoppel 422869SchenefeldGermany
- Department of Experimental Physics, Universität HamburgJungiusstraße 920355HamburgGermany
- Stanford Institute for Materials and Energy SciencesSLAC National Accelerator LaboratoryMenlo ParkCA94025USA
| | | | - Zoltán Németh
- Wigner Research Centre for PhysicsH-1525BudapestHungary
| | - György Vankó
- Wigner Research Centre for PhysicsH-1525BudapestHungary
| | - Nils Rockstroh
- Leibniz-Institut für KatalyseAlbert-Einstein-Str. 29a18059RostockGermany
| | - Henrik Junge
- Leibniz-Institut für KatalyseAlbert-Einstein-Str. 29a18059RostockGermany
| | - Matthias Beller
- Leibniz-Institut für KatalyseAlbert-Einstein-Str. 29a18059RostockGermany
| | - Gilles Doumy
- Chemical Sciences and Engineering DivisionArgonne National Laboratory9700 S. Cass Ave60439LemontILUSA
| | - Anne Marie March
- Chemical Sciences and Engineering DivisionArgonne National Laboratory9700 S. Cass Ave60439LemontILUSA
| | - Stephen H. Southworth
- Chemical Sciences and Engineering DivisionArgonne National Laboratory9700 S. Cass Ave60439LemontILUSA
| | - Stefan Lochbrunner
- Institut für PhysikUniversität RostockAlbert-Einstein-Str. 23–2418059RostockGermany
| | - Oliver Kühn
- Institut für PhysikUniversität RostockAlbert-Einstein-Str. 23–2418059RostockGermany
| | - Christian Bressler
- European XFELHolzkoppel 422869SchenefeldGermany
- The Hamburg Centre for Ultrafast ImagingLuruper Chaussee 14922761HamburgGermany
- Department of Experimental Physics, Universität HamburgJungiusstraße 920355HamburgGermany
| | - Wojciech Gawelda
- European XFELHolzkoppel 422869SchenefeldGermany
- Faculty of PhysicsAdam Mickiewicz Universityul. Uniwersytetu Poznańskiego 2Poznań61-614Poland
- Department of ChemistryFaculty of SciencesUniversidad Autónoma de Madrid and IMDEA-NanoscienceCiudad Universitaria de Cantoblanco28049MadridSpain
| |
Collapse
|
14
|
Bevernaegie R, Wehlin SAM, Elias B, Troian‐Gautier L. A Roadmap Towards Visible Light Mediated Electron Transfer Chemistry with Iridium(III) Complexes. CHEMPHOTOCHEM 2021. [DOI: 10.1002/cptc.202000255] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Robin Bevernaegie
- Laboratoire de Chimie Organique CP160/06 Université libre de Bruxelles 50 avenue F. R. Roosevelt 1050 Brussels Belgium
- Institut de la Matière Condensée et des Nanosciences (IMCN) Molecular Chemistry, Materials and Catalysis (MOST) Université catholique de Louvain (UCLouvain) Place Louis Pasteur 1 box L4.01.02 1348 Louvain-la-Neuve Belgium
| | - Sara A. M. Wehlin
- Laboratoire de Chimie Organique CP160/06 Université libre de Bruxelles 50 avenue F. R. Roosevelt 1050 Brussels Belgium
| | - Benjamin Elias
- Institut de la Matière Condensée et des Nanosciences (IMCN) Molecular Chemistry, Materials and Catalysis (MOST) Université catholique de Louvain (UCLouvain) Place Louis Pasteur 1 box L4.01.02 1348 Louvain-la-Neuve Belgium
| | - Ludovic Troian‐Gautier
- Laboratoire de Chimie Organique CP160/06 Université libre de Bruxelles 50 avenue F. R. Roosevelt 1050 Brussels Belgium
| |
Collapse
|
15
|
Choi J, Ahn M, Lee JH, Ahn DS, Ki H, Oh I, Ahn CW, Choi EH, Lee Y, Lee S, Kim J, Cho DW, Wee KR, Ihee H. Ultrafast excited state relaxation dynamics in a heteroleptic Ir( iii) complex, fac-Ir(ppy) 2(ppz), revealed by femtosecond X-ray transient absorption spectroscopy. Inorg Chem Front 2021. [DOI: 10.1039/d0qi01510e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The experimental and calculation results demonstrate that the 3MLppzCT state generated by the spin-forbidden transition rapidly relaxes to 3MLppyCT through internal conversion process with a time constant of ∼450 fs.
Collapse
|
16
|
Hwang J, Ahn M, Choi J, Wee KR. Inter-Ligand Energy Transfer Process in an Ir-Complex with Expanding π-Conjugated Ligand. Chemphyschem 2020; 21:2320-2326. [PMID: 32812341 DOI: 10.1002/cphc.202000565] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/10/2020] [Indexed: 11/11/2022]
Abstract
The inter-ligand energy transfer (ILET) process in heteroleptic iridium complex, [Ir(dfppy)2 (bpy-Im2 )]+ , where dfppy=2-(2,4-difluorophenyl)pyridine and bpy-Im2 =4,4'-bis(1,2-diphenyl-1H-benzo[d]imidazole)-2,2',-bipyridine, was investigated using a femtosecond transient absorption (fs-TA) spectroscopic technique. The photophysical properties of [Ir(dfppy)2 (bpy-Im2 )]+ with significantly expanding π-conjugated ligand are compared to those of [Ir(dfppy)2 (bpy)]+ (bpy=2,2'-bipyridine) and a free bpy-Im2 ligand. The emission spectrum of [Ir(dfppy)2 (bpy-Im2 )]+ shows no shift upon changing the solvent polarity, whereas the free ligand bpy-Im2 showed bathochromic fluorescence shifts with increasing solvent polarity, which is attributed to intramolecular charge transfer (ICT). The unique photophysical properties of [Ir(dfppy)2 (bpy-Im2 )]+ are due to the fast ILET process from 3 MLCTdfppy to 3 MLCT/3 LCbpy-Im2 , resulting in the phosphorescence emission originating from 3 MLCT/3 LCbpy-Im2 . On the other hand, the TA bands of bpy-Im2 are observed at 540 and 480 nm, corresponding to the singlet and triplet manifolds, respectively. In contrast, the TA spectrum of [Ir(dfppy)2 (bpy-Im2 )]+ showes broad bands centered at 420 and 600 nm, attributed to the transitions from 3 MLCTdfppy and 3 MLCT/3 LCbpy-Im2 , respectively. Time-resolved spectroscopic results confirm the efficient ILET dynamics from 3 MLCTdfppy to 3 MLCT/3 LCbpy-Im2 in [Ir(dfppy)2 (bpy-Im2 )]+ . From the relaxation times determined by singular value decomposition analysis and simple sequential kinetic model, we infer that the ILET process from 3 MLCTdfppy to 3 MLCT/3 LCbpy-Im2 occurs with a time constant of ca. 4 ps. The presented results in this study show that the introduction of an expanding π-conjugated ligand can lead to the efficient ILET dynamics for improving the OLED performance.
Collapse
Affiliation(s)
- Jeongwook Hwang
- Department of chemistry, Daegu University, Gyeongsan, 38453, Republic of Korea
| | - Mina Ahn
- Department of chemistry, Daegu University, Gyeongsan, 38453, Republic of Korea
| | - Jungkweon Choi
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea.,Department of Chemistry and KI of the Biocentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Kyung-Ryang Wee
- Department of chemistry, Daegu University, Gyeongsan, 38453, Republic of Korea
| |
Collapse
|
17
|
Luo Y, Maloul S, Schönweiz S, Wächtler M, Streb C, Dietzek B. Yield-not only Lifetime-of the Photoinduced Charge-Separated State in Iridium Complex-Polyoxometalate Dyads Impact Their Hydrogen Evolution Reactivity. Chemistry 2020; 26:8045-8052. [PMID: 32237163 PMCID: PMC7383969 DOI: 10.1002/chem.202000982] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Indexed: 11/11/2022]
Abstract
Covalently linked photosensitizer-polyoxometalate (PS-POM) dyads are promising molecular systems for light-induced energy conversion processes, such as "solar" hydrogen generation. To date, very little is known of their fundamental photophysical properties which affect the catalytic reactivity and stability of the systems. PS-POM dyads often feature short-lived photoinduced charge-separated states, and the lifetimes of these states are considered crucial for the function of PS-POM dyads in molecular photocatalysis. Hence, strategies have been developed to extend the lifetimes of the photoinduced charge-separated states, either by tuning the PS photophysics or by tuning the POM redox properties. Recently, some of us reported PS-POM dyads based on cyclometalated IrIII complexes covalently linked to Anderson-type polyoxometalate. Distinct hydrogen evolution reactivity (HER) of the dyads was observed, which was tuned by varying the central metal ion M of the POMM (M=Mn3+ , Co3+ , Fe3+ ). In this manuscript, the photoinduced electron-transfer processes in the three Ir-POMM dyads are investigated to rationalize the underlying reasons for the differences in HER activity observed. We report that upon excitation of the IrIII complex, ultrafast (sub-ps) charge separation occurs, leading to different amounts of the charge-separated states (Ir.+ -POMM .- ) generated in the different dyads. However, in all dyads studied, the resulting Ir.+ -POMM .- species are short-lived (sub-ns) when compared to reference electron acceptors (e.g. porphyrins or fullerenes) reported in the literature. The reductive quenching of Ir.+ -POMM .- by a sacrificial donor, triethyl amine (1 m), to generate the intermediate Ir-POMM .- is estimated to be very efficient (70-80 %) for all dyads studied. Based on this analyses, we conclude that the yield instead of the lifetime of the Ir.+ -POMM .- charge-separated state determines the catalytic capacity of the dyads investigated. This new feature in the PS-POM photophysics could lead to new design criteria for the development of novel PS-POM dyads.
Collapse
Affiliation(s)
- Yusen Luo
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Strasse 9, 07745, Jena, Germany
| | - Salam Maloul
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Stefanie Schönweiz
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Maria Wächtler
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Strasse 9, 07745, Jena, Germany
| | - Carsten Streb
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Benjamin Dietzek
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Strasse 9, 07745, Jena, Germany.,Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich-Schiller-University Jena, Philosophenweg 7a, 07743, Jena, Germany
| |
Collapse
|
18
|
Wahyuono RA, Amthor S, Müller C, Rau S, Dietzek B. Structure of Diethyl‐Phosphonic Acid Anchoring Group Affects the Charge‐Separated State on an Iridium(III) Complex Functionalized NiO Surface. CHEMPHOTOCHEM 2020. [DOI: 10.1002/cptc.202000038] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Ruri Agung Wahyuono
- Department Functional InterfacesLeibniz Institute of Photonic Technology (IPHT) Jena e.V. Albert-Einstein-Straße 9 07745 Jena Germany
- Institute of Physical ChemistryFriedrich Schiller University Jena Helmholtzweg 4 07743 Jena Germany
| | - Sebastian Amthor
- Institute of Inorganic Chemistry IUniversity Ulm Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Carolin Müller
- Department Functional InterfacesLeibniz Institute of Photonic Technology (IPHT) Jena e.V. Albert-Einstein-Straße 9 07745 Jena Germany
- Institute of Physical ChemistryFriedrich Schiller University Jena Helmholtzweg 4 07743 Jena Germany
| | - Sven Rau
- Institute of Inorganic Chemistry IUniversity Ulm Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Benjamin Dietzek
- Department Functional InterfacesLeibniz Institute of Photonic Technology (IPHT) Jena e.V. Albert-Einstein-Straße 9 07745 Jena Germany
- Institute of Physical ChemistryFriedrich Schiller University Jena Helmholtzweg 4 07743 Jena Germany
- Center for Energy and Environmental Chemistry (CEEC)Friedrich Schiller University Jena Philosophenweg 7a 07743 Jena Germany
| |
Collapse
|
19
|
Scattergood PA, Ranieri AM, Charalambou L, Comia A, Ross DAW, Rice CR, Hardman SJO, Heully JL, Dixon IM, Massi M, Alary F, Elliott PIP. Unravelling the Mechanism of Excited-State Interligand Energy Transfer and the Engineering of Dual Emission in [Ir(C ∧N) 2(N ∧N)] + Complexes. Inorg Chem 2020; 59:1785-1803. [PMID: 31934759 DOI: 10.1021/acs.inorgchem.9b03003] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Fundamental insights into the mechanism of triplet-excited-state interligand energy transfer dynamics and the origin of dual emission for phosphorescent iridium(III) complexes are presented. The complexes [Ir(C∧N)2(N∧N)]+ (HC∧N = 2-phenylpyridine (1a-c), 2-(2,4-difluorophenyl)pyridine (2a-c), 1-benzyl-4-phenyl-1,2,3-triazole (3a-c); N∧N = 1-benzyl-4-(pyrid-2-yl)-1,2,3-triazole (pytz, a), 1-benzyl-4-(pyrimidin-2-yl)-1,2,3-triazole (pymtz, b), 1-benzyl-4-(pyrazin-2-yl)-1,2,3-triazole (pyztz, c)) are phosphorescent in room-temperature fluid solutions from triplet metal-to-ligand charge transfer (3MLCT) states admixed with either ligand-centered (3LC) (1a, 2a, and 2b) or ligand-to-ligand charge transfer (3LL'CT) character (1c, 2c, and 3a-c). Particularly striking is the observation that pyrimidine-based complex 1b exhibits dual emission from both 3MLCT/3LC and 3MLCT/3LL'CT states. At 77 K, the 3MLCT/3LL'CT component is lost from the photoluminescence spectra of 1b, with emission exclusively arising from its 3MLCT/3LC state, while for 2c switching from 3MLCT/3LL'CT- to 3MLCT/3LC-based emission is observed. Femtosecond transient absorption data reveal distinct spectral signatures characteristic of the population of 3MLCT/3LC states for 1a, 2a, and 2b which persist throughout the 3 ns time frame of the experiment. These 3MLCT/3LC state signatures are apparent in the transient absorption spectra for 1c and 2c immediately following photoexcitation but rapidly evolve to yield spectral profiles characteristic of their 3MLCT/3LL'CT states. Transient data for 1b reveals intermediate behavior: the spectral features of the initially populated 3MLCT/3LC state also undergo rapid evolution, although to a lesser extent than that observed for 1c and 2c, behavior assigned to the equilibration of the 3MLCT/3LC and 3MLCT/3LL'CT states. Density functional theory (DFT) calculations enabled minima to be optimized for both 3MLCT/3LC and 3MLCT/3LL'CT states of 1a-c and 2a-c. Indeed, two distinct 3MLCT/3LC minima were optimized for 1a, 1b, 2a, and 2b distinguished by upon which of the two C∧N ligands the excited electron resides. The 3MLCT/3LC and 3MLCT/3LL'CT states for 1b are very close in energy, in excellent agreement with experimental data demonstrating dual emission. Calculated vibrationally resolved emission spectra (VRES) for the complexes are in excellent agreement with experimental data, with the overlay of spectral maxima arising from emission from the 3MLCT/3LC and 3MLCT/3LL'CT states of 1b convincingly reproducing the observed experimental spectral features. Analysis of the optimized excited-state geometries enable the key structural differences between the 3MLCT/3LC and 3MLCT/3LL'CT states of the complexes to be identified and quantified. The calculation of interconversion pathways between triplet excited states provides for the first time a through-space mechanism for a photoinduced interligand energy transfer process. Furthermore, examination of structural changes between the possible emitting triplet excited states reveals the key bond vibrations that mediate energy transfer between these states. This work therefore provides for the first time detailed mechanistic insights into the fundamental photophysical processes of this important class of complexes.
Collapse
Affiliation(s)
- Paul A Scattergood
- Department of Chemistry , University of Huddersfield , Huddersfield HD1 3DH , United Kingdom.,Centre for Functional Materials , University of Huddersfield , Huddersfield HD1 3DH , United Kingdom
| | - Anna M Ranieri
- School of Molecular and Life Sciences - Curtin Institute for Functional Materials and Interfaces , Curtin University , Building 500, Kent Street , Bentley , Western Australia 6845 , Australia
| | - Luke Charalambou
- Department of Chemistry , University of Huddersfield , Huddersfield HD1 3DH , United Kingdom
| | - Adrian Comia
- Department of Chemistry , University of Huddersfield , Huddersfield HD1 3DH , United Kingdom
| | - Daniel A W Ross
- Department of Chemistry , University of Huddersfield , Huddersfield HD1 3DH , United Kingdom
| | - Craig R Rice
- Department of Chemistry , University of Huddersfield , Huddersfield HD1 3DH , United Kingdom
| | - Samantha J O Hardman
- Manchester Institute of Biotechnology , The University of Manchester , 131 Princess Street , Manchester M1 7DN , United Kingdom
| | - Jean-Louis Heully
- Laboratoire de Chimie et Physique Quantiques , UMR 5626 CNRS/Université Toulouse 3 - Paul Sabatier, Université de Toulouse , 118 route de Narbonne , Toulouse 31062 , France
| | - Isabelle M Dixon
- Laboratoire de Chimie et Physique Quantiques , UMR 5626 CNRS/Université Toulouse 3 - Paul Sabatier, Université de Toulouse , 118 route de Narbonne , Toulouse 31062 , France
| | - Massimiliano Massi
- School of Molecular and Life Sciences - Curtin Institute for Functional Materials and Interfaces , Curtin University , Building 500, Kent Street , Bentley , Western Australia 6845 , Australia
| | - Fabienne Alary
- Laboratoire de Chimie et Physique Quantiques , UMR 5626 CNRS/Université Toulouse 3 - Paul Sabatier, Université de Toulouse , 118 route de Narbonne , Toulouse 31062 , France
| | - Paul I P Elliott
- Department of Chemistry , University of Huddersfield , Huddersfield HD1 3DH , United Kingdom.,Centre for Functional Materials , University of Huddersfield , Huddersfield HD1 3DH , United Kingdom
| |
Collapse
|
20
|
Viertl W, Pann J, Pehn R, Roithmeyer H, Bendig M, Rodríguez-Villalón A, Bereiter R, Heiderscheid M, Müller T, Zhao X, Hofer TS, Thompson ME, Shi S, Brueggeller P. Performance of enhanced DuBois type water reduction catalysts (WRC) in artificial photosynthesis - effects of various proton relays during catalysis. Faraday Discuss 2019; 215:141-161. [PMID: 30942209 DOI: 10.1039/c8fd00162f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Inspired by natural photosynthesis, features such as proton relays have been integrated into water reduction catalysts (WRC) for effective production of hydrogen. Research by DuBois et al. showed the crucial influence of these relays, largely in the form of pendant amine functions. In this work catalysts are presented containing innovative diphosphinoamine ligands: [M(ii)Cl2(PNP-C1)], [M(ii)(MeCN)2(PNP-C1)]2+, [M(ii)(PNP-C1)2]2+, and [M(ii)Cl(PNP-C2)]+ (M = Pt2+, Pd2+, Ni2+, Co2+; PNP-C1 = N,N-bis{(di(2-methoxyphenyl)phosphino)methyl}-N-alkylamine, PNP-C2 = N,N-bis{(di(2-methoxyphenyl)phosphino)ethyl}-N-alkylamine and alkyl = Me, Et, iso-Pr, Bz). Synthetic strategies and detailed characterisation are covered, including 1H-, 13C-, and 31P-NMR analysis, mass spectroscopy and single crystal X-ray diffractometry (XRD). The catalytic properties have been explored by changing the pendant amines and auxiliary methoxy coordination sites, as well as enlarging the ligand backbone. Moreover, confirmed by density functional theory (DFT) calculations based on XRD data in vacuo and solvent environment, two very different catalytic cycles are proposed. PNP-C1 shows a classical proton relay, whereas PNP-C2 allows an additional coordination of nitrogen, acting optionally like a pincer. Through new insights into efficiency and stability-increasing influences of proton relays in general, their number per metal centre, an enlarged ligand backbone and the use of solvato instead of halogenido complexes, substantial improvements have been made in catalytic performance over the DuBois et al. catalysts and recently self-made WRCs. The turnover number (TON) related to the single site of cost-efficient nickel WRCs is increased from 11.4 to 637, whereas a corresponding palladium catalyst gives TON as high as 2289.
Collapse
Affiliation(s)
- Wolfgang Viertl
- University of Innsbruck, Centrum for Chemistry and Biomedicine, Institute of General, Inorganic and Theoretical Chemistry, Innrain 82, 6020 Innsbruck, Austria
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Erdmann E, Lütgens M, Lochbrunner S, Seidel WW. Ultrafast Energy Transfer in Dinuclear Complexes with Bridging 1,10-Phenanthroline-5,6-Dithiolate. Inorg Chem 2018; 57:4849-4863. [PMID: 29664619 DOI: 10.1021/acs.inorgchem.7b02840] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We report herein the preparation and characterization of dinuclear complexes with the bridging ligand 1,10-phenanthroline-5,6-dithiolate (phendt2-) bearing Ru(bpy)2 or Ir(ppy)2 at the diimine moiety and Ni(dppe), Ni(dppf), CoCp, RhCp*, and Ru( p-Me-iPr-benzene) at the dithiolate unit. In comparison with the mononuclear precursors used in the synthesis, all dinuclear complexes were characterized by absorption and photoluminescence spectroscopy as well as cyclic voltammetry. Because of the beneficial spectral and electrochemical properties of the Ir/Co complex for a light-driven charge separation, this complex was investigated in detail by time-resolved luminescence {nanosecond (ns)-resolution} and transient absorption spectroscopy {femtosecond (fs)-resolution}. All measurements supported by DFT calculations show that the observed effective luminescence quenching by the dithiolate coordinated metal is caused by an ultrafast singlet-singlet Dexter energy transfer.
Collapse
|
22
|
Bevernaegie R, Marcélis L, Moreno-Betancourt A, Laramée-Milette B, Hanan GS, Loiseau F, Sliwa M, Elias B. Ultrafast charge transfer excited state dynamics in trifluoromethyl-substituted iridium(iii) complexes. Phys Chem Chem Phys 2018; 20:27256-27260. [DOI: 10.1039/c8cp04265a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Ultrafast spectroscopic studies on the excited state interplay in trifluoromethyl-substituted iridium(iii) complexes.
Collapse
Affiliation(s)
- Robin Bevernaegie
- Université catholique de Louvain (UCL)
- Institut de la Matière Condensée et des Nanosciences (IMCN)
- B-1348 Louvain-la-Neuve
- Belgium
| | - Lionel Marcélis
- Université catholique de Louvain (UCL)
- Institut de la Matière Condensée et des Nanosciences (IMCN)
- B-1348 Louvain-la-Neuve
- Belgium
| | | | | | - Garry S. Hanan
- Département de Chimie
- Université de Montréal, Montréal
- Québec
- Canada
| | - Frédérique Loiseau
- Département de Chimie Moléculaire
- Université Grenoble-Alpes
- CNRS UMR 5250
- BP53 38041 Grenoble
- France
| | - Michel Sliwa
- Université de Lille
- CNRS
- UMR 8516
- LASIR
- Laboratoire de Spectrochimie Infrarouge et Raman
| | - Benjamin Elias
- Université catholique de Louvain (UCL)
- Institut de la Matière Condensée et des Nanosciences (IMCN)
- B-1348 Louvain-la-Neuve
- Belgium
| |
Collapse
|
23
|
Erdmann E, Villinger A, König B, Seidel WW. 1,10-Phenanthroline-dithiine iridium and ruthenium complexes: synthesis, characterization and photocatalytic dihydrogen evolution. Photochem Photobiol Sci 2018; 17:1056-1067. [DOI: 10.1039/c8pp00068a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Extending 1,10-phenanthroline with a dithiine link led to a remarkable increase of the luminescence lifetimes of the respective Ir(ppy)2 and Ru(bpy)2 complexes.
Collapse
Affiliation(s)
- E. Erdmann
- Institute of Organic Chemistry
- Faculty of Chemistry and Pharmacy
- Universität Regensburg
- 93053 Regensburg
- Germany
| | - A. Villinger
- Institut für Chemie
- Universität Rostock
- 18059 Rostock
- Germany
| | - B. König
- Institute of Organic Chemistry
- Faculty of Chemistry and Pharmacy
- Universität Regensburg
- 93053 Regensburg
- Germany
| | - W. W. Seidel
- Institut für Chemie
- Universität Rostock
- 18059 Rostock
- Germany
| |
Collapse
|
24
|
Kobayashi A, Watanabe S, Ebina M, Yoshida M, Kato M. Effects of phosphonate ester groups attached on a heteroleptic Ir(III) photosensitizer. J Photochem Photobiol A Chem 2017. [DOI: 10.1016/j.jphotochem.2017.06.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
25
|
Chemical Tuning and Absorption Properties of Iridium Photosensitizers for Photocatalytic Applications. INORGANICS 2017. [DOI: 10.3390/inorganics5020023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
26
|
Light to Hydrogen: Photocatalytic Hydrogen Generation from Water with Molecularly-Defined Iron Complexes. INORGANICS 2017. [DOI: 10.3390/inorganics5010014] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
|