1
|
Reinhard ME, Sidhu BK, Lozada IB, Powers-Riggs N, Ortiz RJ, Lim H, Nickel R, Lierop JV, Alonso-Mori R, Chollet M, Gee LB, Kramer PL, Kroll T, Raj SL, van Driel TB, Cordones AA, Sokaras D, Herbert DE, Gaffney KJ. Time-Resolved X-ray Emission Spectroscopy and Synthetic High-Spin Model Complexes Resolve Ambiguities in Excited-State Assignments of Transition-Metal Chromophores: A Case Study of Fe-Amido Complexes. J Am Chem Soc 2024; 146:17908-17916. [PMID: 38889309 DOI: 10.1021/jacs.4c02748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
To fully harness the potential of abundant metal coordination complex photosensitizers, a detailed understanding of the molecular properties that dictate and control the electronic excited-state population dynamics initiated by light absorption is critical. In the absence of detectable luminescence, optical transient absorption (TA) spectroscopy is the most widely employed method for interpreting electron redistribution in such excited states, particularly for those with a charge-transfer character. The assignment of excited-state TA spectral features often relies on spectroelectrochemical measurements, where the transient absorption spectrum generated by a metal-to-ligand charge-transfer (MLCT) electronic excited state, for instance, can be approximated using steady-state spectra generated by electrochemical ligand reduction and metal oxidation and accounting for the loss of absorptions by the electronic ground state. However, the reliability of this approach can be clouded when multiple electronic configurations have similar optical signatures. Using a case study of Fe(II) complexes supported by benzannulated diarylamido ligands, we highlight an example of such an ambiguity and show how time-resolved X-ray emission spectroscopy (XES) measurements can reliably assign excited states from the perspective of the metal, particularly in conjunction with accurate synthetic models of ligand-field electronic excited states, leading to a reinterpretation of the long-lived excited state as a ligand-field metal-centered quintet state. A detailed analysis of the XES data on the long-lived excited state is presented, along with a discussion of the ultrafast dynamics following the photoexcitation of low-spin Fe(II)-Namido complexes using a high-spin ground-state analogue as a spectral model for the 5T2 excited state.
Collapse
Affiliation(s)
- Marco E Reinhard
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Baldeep K Sidhu
- Department of Chemistry and the Manitoba Institute for Materials, University of Manitoba, 144 Dysart Rd, Winnipeg, Manitoba R3T 2N2, Canada
| | - Issiah B Lozada
- Department of Chemistry and the Manitoba Institute for Materials, University of Manitoba, 144 Dysart Rd, Winnipeg, Manitoba R3T 2N2, Canada
| | - Natalia Powers-Riggs
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Robert J Ortiz
- Department of Chemistry and the Manitoba Institute for Materials, University of Manitoba, 144 Dysart Rd, Winnipeg, Manitoba R3T 2N2, Canada
| | - Hyeongtaek Lim
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Rachel Nickel
- Department of Physics and Astronomy, University of Manitoba, 31A Sifton Rd, Winnipeg, Manitoba R3T 2N2, Canada
| | - Johan van Lierop
- Department of Physics and Astronomy, University of Manitoba, 31A Sifton Rd, Winnipeg, Manitoba R3T 2N2, Canada
| | - Roberto Alonso-Mori
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Matthieu Chollet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Leland B Gee
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Patrick L Kramer
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Thomas Kroll
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Sumana L Raj
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Tim B van Driel
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Amy A Cordones
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - David E Herbert
- Department of Chemistry and the Manitoba Institute for Materials, University of Manitoba, 144 Dysart Rd, Winnipeg, Manitoba R3T 2N2, Canada
| | - Kelly J Gaffney
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| |
Collapse
|
2
|
Xu X, Marlton SJP, Flint KL, Hudson RJ, Keene FR, Hall CR, Smith TA. Photophysical Studies of Helicate and Mesocate Double-Stranded Dinuclear Ru(II) Complexes. J Phys Chem A 2024. [PMID: 38640443 DOI: 10.1021/acs.jpca.4c01996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2024]
Abstract
The metal-ligand charge transfer (3MLCT) and phosphorescence-quenching metal-centered (3MC) states of the helicate and mesocate diastereoisomers of a double-stranded dinuclear polypyridylruthenium(II) complex have been investigated using ultrafast transient absorption spectroscopy. At 294 K, transient signals of the helicate decayed significantly slower than those of the mesocate, whereas at 77 K, no clear contrast in kinetics was observed. Contributions to excited-state decay from high-lying 3MLCT states were identified at both temperatures. Spectroscopic data (294 K) suggest that the 3MC state of the helicate lies above the 3MLCT and that the reverse is true for the mesocate; this was further validated by density functional theory calculations. The stabilization of the 3MC state relative to the 3MLCT state in the mesocate was explained by a reduction in ligand field strength due to distortion near the ligand bridge, which causes further deviation from octahedral geometry compared to the helicate. This work illustrates how minor structural differences can significantly influence excited state dynamics.
Collapse
Affiliation(s)
- Xinyue Xu
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- ARC Centre of Excellence in Exciton Science, Parkville, Victoria 3010, Australia
| | - Samuel J P Marlton
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Kate L Flint
- Discipline of Chemistry, School of Physics, Chemistry and Earth Sciences, The University of Adelaide, South Australia 5005, Australia
| | - Rohan J Hudson
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- ARC Centre of Excellence in Exciton Science, Parkville, Victoria 3010, Australia
| | - F Richard Keene
- Discipline of Chemistry, School of Physics, Chemistry and Earth Sciences, The University of Adelaide, South Australia 5005, Australia
| | - Christopher R Hall
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- ARC Centre of Excellence in Exciton Science, Parkville, Victoria 3010, Australia
| | - Trevor A Smith
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- ARC Centre of Excellence in Exciton Science, Parkville, Victoria 3010, Australia
| |
Collapse
|
3
|
Yarranton JT, McCusker JK. Ligand-Field Spectroscopy of Co(III) Complexes and the Development of a Spectrochemical Series for Low-Spin d 6 Charge-Transfer Chromophores. J Am Chem Soc 2022; 144:12488-12500. [PMID: 35749670 DOI: 10.1021/jacs.2c04945] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A study of a series of six-coordinate Co(III) complexes has been carried out to quantify spectroscopic parameters for a range of ligands that are commonly employed to realize strong charge-transfer absorptions in low-spin, d6 systems. Identification of any three ligand-field transitions allows for the determination of the splitting parameter (10 Dq) as well as the Racah B and C parameters for a given compound. The data revealed a relatively small spread in the magnitude of 10 Dq, ranging from ca. 23 000 cm-1 in the case of [Co(pyrro-bpy)3]3+ (where pyrro-bpy is 4,4'-dipyrrolidinyl-2,2'-bipyridine) to ca. 26 000 cm-1 for [Co(terpy)2]3+ (where terpy is 2,2':6',2″-terpyridine). Significantly, trends across the series suggest that polypyridyl ligands behave as net π-donors when interacting with Co(III), in contrast to the net π-accepting character they exhibit when bound to second- and third-row metals. The influence of strong σ donation associated with carbene-based ligands was evident from the data acquired for [Co(BMeImPy)2]3+ (where BMeImPy is 3,3'-(pyridine-2,6-diyl)bis(1-methyl-1H-3-imidazolium)), where a 10 Dq value of ca. 30 000 cm-1 was determined. Spectroscopic data were also analyzed for [Fe(bpy)3]2+ using the results on [Co(bpy)3]3+ as a reference point. A value for 10 Dq of 21 000 cm-1 was estimated, indicating a reduction in the ligand-field strength of ca. 3000 cm-1 upon replacing Co(III) with Fe(II). We suggest that this approach of taking advantage of the blueshift of the charge-transfer feature in Co(III) complexes to reveal otherwise obscured ligand-field bands can be a useful tool for the development of new ligand systems to expand the photofunctionality of first-row transition-metal-based chromophores.
Collapse
Affiliation(s)
- Jonathan T Yarranton
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - James K McCusker
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| |
Collapse
|
4
|
Yu X, Gao F, Zhao W, Lai H, Wei L, Yang C, Wu W. BODIPY-conjugated bis-terpyridine Ru(II) complexes showing ultra-long luminescence lifetimes and applications to triplet-triplet annihilation upconversion. Dalton Trans 2022; 51:9314-9322. [PMID: 35670531 DOI: 10.1039/d2dt01373h] [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 poor excited-state properties of bis-terpyridine Ru(II) complexes have significantly limited the applications of these complexes as sensitizers in photocatalysis and triplet-triplet annihilation upconversion. In the present work, two novel ruthenium bis-terpyridine complexes (Ru-1 and Ru-2) conjugated with visible-light-harvesting bodipy chromophores were synthesized. These complexes showed strong absorption of visible light, the bodipy-localized intraligand triplet state (3IL) was efficiently populated, and the phosphorescence of bodipy at room temperature in both complexes was observed. The luminescence lifetimes of these complexes were significantly prolonged, with that of the heteroleptic complex Ru-2 prolonged to 37.9 μs and that of the homoleptic bis-terpyridine complex Ru-1 unprecedentedly prolonged to 356 μs, which was hundreds of times longer than the current longest emissive state achieved in ruthenium terpyridine complexes. The ultra-long triplet lifetimes and strong visible-light absorbing ability made them new candidates of triplet sensitizers, and were first applied to TTA-UC for terpyridine Ru(II) complexes with a Ru-1/Py system showing a ΦUC of 2.93% in dilute solutions at concentrations as low as 1.0 μM.
Collapse
Affiliation(s)
- Xingke Yu
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Fanrui Gao
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Weiyi Zhao
- Sichuan University-Pittsburgh Institute, Sichuan University, Chengdu 610064, China
| | - Hongxia Lai
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Lingling Wei
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Cheng Yang
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Wanhua Wu
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
| |
Collapse
|
5
|
Alcover-Fortuny G, Wu J, Caballol R, de Graaf C. Quantum Chemical Study of the Interligand Electron Transfer in Ru Polypyridyl Complexes. J Phys Chem A 2018; 122:1114-1123. [PMID: 29272128 DOI: 10.1021/acs.jpca.7b11422] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gerard Alcover-Fortuny
- Departament
de Química Fı́sica i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007 Tarragona, Spain
| | - Jianfang Wu
- Departament
de Química Fı́sica i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007 Tarragona, Spain
| | - Rosa Caballol
- Departament
de Química Fı́sica i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007 Tarragona, Spain
| | - Coen de Graaf
- Departament
de Química Fı́sica i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007 Tarragona, Spain
- ICREA, Pg. Lluis Companys 23, 08010 Barcelona, Spain
| |
Collapse
|
6
|
Fatur SM, Shepard SG, Higgins RF, Shores MP, Damrauer NH. A Synthetically Tunable System To Control MLCT Excited-State Lifetimes and Spin States in Iron(II) Polypyridines. J Am Chem Soc 2017; 139:4493-4505. [DOI: 10.1021/jacs.7b00700] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Steven M. Fatur
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Samuel G. Shepard
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Robert F. Higgins
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Matthew P. Shores
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Niels H. Damrauer
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| |
Collapse
|
7
|
Dixon IM, Heully JL, Alary F, Elliott PIP. Theoretical illumination of highly original photoreactive3MC states and the mechanism of the photochemistry of Ru(ii) tris(bidentate) complexes. Phys Chem Chem Phys 2017; 19:27765-27778. [DOI: 10.1039/c7cp05532c] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Elucidation of the photoreactive mechanism of ruthenium(ii) complexes is reported along with identification of crucial and highly original metal-centred states.
Collapse
Affiliation(s)
- Isabelle M. Dixon
- Laboratoire de Chimie et Physique Quantiques
- UMR 5626 CNRS/Université Toulouse 3 – Paul Sabatier
- Université de Toulouse
- Toulouse
- France
| | - Jean-Louis Heully
- Laboratoire de Chimie et Physique Quantiques
- UMR 5626 CNRS/Université Toulouse 3 – Paul Sabatier
- Université de Toulouse
- Toulouse
- France
| | - Fabienne Alary
- Laboratoire de Chimie et Physique Quantiques
- UMR 5626 CNRS/Université Toulouse 3 – Paul Sabatier
- Université de Toulouse
- Toulouse
- France
| | | |
Collapse
|
8
|
Fredin LA, Persson P. Computational characterization of competing energy and electron transfer states in bimetallic donor-acceptor systems for photocatalytic conversion. J Chem Phys 2016; 145:104310. [PMID: 27634263 PMCID: PMC5181788 DOI: 10.1063/1.4962254] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The rapidly growing interest in photocatalytic systems for direct solar fuel production such as hydrogen generation from water splitting is grounded in the unique opportunity to achieve charge separation in molecular systems provided by electron transfer processes. In general, both photoinduced and catalytic processes involve complicated dynamics that depend on both structural and electronic effects. Here the excited state landscape of metal centered light harvester-catalyst pairs is explored using density functional theory calculations. In weakly bound systems, the interplay between structural and electronic factors involved can be constructed from the various mononuclear relaxed excited states. For this study, supramolecular states of electron transfer and excitation energy transfer character have been constructed from constituent full optimizations of multiple charge/spin states for a set of three Ru-based light harvesters and nine transition metal catalysts (based on Ru, Rh, Re, Pd, and Co) in terms of energy, structure, and electronic properties. The complete set of combined charge-spin states for each donor-acceptor system provides information about the competition of excited state energy transfer states with the catalytically active electron transfer states, enabling the identification of the most promising candidates for photocatalytic applications from this perspective.
Collapse
Affiliation(s)
- Lisa A. Fredin
- Chemical Informatics Research Group, Chemical Sciences Division, Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Mailstop 8320, Gaithersburg, MD
| | - Petter Persson
- Chemistry Department, Theoretical Chemistry Division, Lund University, Box 124, SE-22100 Lund, Sweden
| |
Collapse
|
9
|
Shepard SG, Fatur SM, Rappé AK, Damrauer NH. Highly Strained Iron(II) Polypyridines: Exploiting the Quintet Manifold To Extend the Lifetime of MLCT Excited States. J Am Chem Soc 2016; 138:2949-52. [DOI: 10.1021/jacs.5b13524] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Samuel G. Shepard
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Steven M. Fatur
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Anthony K. Rappé
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Niels H. Damrauer
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| |
Collapse
|
10
|
Nance J, Bowman DN, Mukherjee S, Kelley CT, Jakubikova E. Insights into the Spin-State Transitions in [Fe(tpy)2]2+: Importance of the Terpyridine Rocking Motion. Inorg Chem 2015; 54:11259-68. [DOI: 10.1021/acs.inorgchem.5b01747] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- James Nance
- Department of Mathematics and ‡Department of
Chemistry, North Carolina State University (NCSU), Raleigh, North Carolina 27695, United States
| | - David N. Bowman
- Department of Mathematics and ‡Department of
Chemistry, North Carolina State University (NCSU), Raleigh, North Carolina 27695, United States
| | - Sriparna Mukherjee
- Department of Mathematics and ‡Department of
Chemistry, North Carolina State University (NCSU), Raleigh, North Carolina 27695, United States
| | - C. T. Kelley
- Department of Mathematics and ‡Department of
Chemistry, North Carolina State University (NCSU), Raleigh, North Carolina 27695, United States
| | - Elena Jakubikova
- Department of Mathematics and ‡Department of
Chemistry, North Carolina State University (NCSU), Raleigh, North Carolina 27695, United States
| |
Collapse
|
11
|
Liao JL, Chi Y, Sie ZT, Ku CH, Chang CH, Fox MA, Low PJ, Tseng MR, Lee GH. Ir(III)-Based Phosphors with Bipyrazolate Ancillaries; Rational Design, Photophysics, and Applications in Organic Light-Emitting Diodes. Inorg Chem 2015; 54:10811-21. [DOI: 10.1021/acs.inorgchem.5b01835] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jia-Ling Liao
- Department
of Chemistry and Low Carbon Energy Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Yun Chi
- Department
of Chemistry and Low Carbon Energy Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Zong-Ting Sie
- Department of Photonics Engineering, Yuan Ze University, Chungli 32003, Taiwan
| | - Chia-Hao Ku
- Department of Photonics Engineering, Yuan Ze University, Chungli 32003, Taiwan
| | - Chih-Hao Chang
- Department of Photonics Engineering, Yuan Ze University, Chungli 32003, Taiwan
| | - Mark A. Fox
- Department of Chemistry, Durham University, South Road, Durham DH1
3LE, U.K
| | - Paul J. Low
- School of Chemistry and
Biochemistry, University of Western Australia, 35 Stirling Highway, Crawley 6009, Western Australia, Australia
| | - Meu-Rurng Tseng
- Material
and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan
| | - Gene-Hsiang Lee
- Instrumentation
Center, National Taiwan University, Taipei 10617, Taiwan
| |
Collapse
|
12
|
Joshi K, Krishnamurty S, Singh I, Selvaraj K. A DFT based assay for tailor-made terpyridine ligand–metal complexation properties. MOLECULAR SIMULATION 2015. [DOI: 10.1080/08927022.2015.1067368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
13
|
Brown AM, McCusker CE, McCusker JK. Spectroelectrochemical identification of charge-transfer excited states in transition metal-based polypyridyl complexes. Dalton Trans 2015; 43:17635-46. [PMID: 25321952 DOI: 10.1039/c4dt02849j] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Identification of transient species is a necessary part of delineating the kinetics and mechanisms associated with chemical dynamics; when dealing with photo-induced processes, this can be an exceptionally challenging task due to the fact that spectra associated with excited state(s) sampled over the course of a photochemical event often cannot be uniquely identified nor readily calculated. Using Group 8 complexes of the general form [M(terpy)2](2+) and [M(bpy)3](2+) as a platform (where terpy is 2,2':6',2''-terpyridine and bpy is 2,2'-bipyridine), we demonstrate how spectroelectrochemical measurements can serve as an effective tool for identifying spectroscopic signatures of charge-transfer excited states of transition metal-based chromophores. Formulating the metal-to-ligand charge-transfer (MLCT) excited state(s) as M(3+)-L(-), the extent to which a linear combination of the spectra of the oxidized and reduced forms of the parent complexes can be used to simulate the characteristic absorptions of MLCT-based transient species is examined. Quantitative agreement is determined to be essentially unachievable due to the fact that certain transitions associated with the optically prepared excited states are either overcompensated for in the spectroelectrochemical data, or simply cannot be replicated through electrochemical means. Despite this limitation, it is shown through several illustrative examples that this approach can still be extremely useful as a qualitative if not semi-quantitative guide for interpreting time-resolved electronic absorption data of charge-transfer compounds, particularly in the ultrafast time domain.
Collapse
Affiliation(s)
- Allison M Brown
- Contribution from the Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, MI 48824, USA.
| | | | | |
Collapse
|
14
|
Wächtler M, Guthmuller J, Kupfer S, Maiuri M, Brida D, Popp J, Rau S, Cerullo G, Dietzek B. Ultrafast Intramolecular Relaxation and Wave-Packet Motion in a Ruthenium-Based Supramolecular Photocatalyst. Chemistry 2015; 21:7668-74. [DOI: 10.1002/chem.201406350] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Indexed: 11/05/2022]
|
15
|
Kuhar K, Fredin LA, Persson P. Exploring Photoinduced Excited State Evolution in Heterobimetallic Ru(II)–Co(III) Complexes. J Phys Chem B 2015; 119:7378-92. [DOI: 10.1021/jp510950u] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Korina Kuhar
- Chemistry
Department, Theoretical
Chemistry Division, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Lisa A. Fredin
- Chemistry
Department, Theoretical
Chemistry Division, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Petter Persson
- Chemistry
Department, Theoretical
Chemistry Division, Lund University, Box 124, SE-22100 Lund, Sweden
| |
Collapse
|
16
|
The influence of ligand localized excited states on the photophysics of second row and third row transition metal terpyridyl complexes: Recent examples and a case study. Coord Chem Rev 2015. [DOI: 10.1016/j.ccr.2014.06.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
17
|
Liu Y, Djurovich PI, Haiges R, Thompson ME. Synthesis and photophysical characterization of a bis-pincer osmium complex. Polyhedron 2014. [DOI: 10.1016/j.poly.2014.06.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
18
|
Spettel KE, Damrauer NH. Synthesis, electrochemical characterization, and photophysical studies of structurally tuned aryl-substituted terpyridyl ruthenium(II) complexes. J Phys Chem A 2014; 118:10649-62. [PMID: 25182073 DOI: 10.1021/jp508145w] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Synthesis, electrochemical potentials, static emission, and temperature-dependent excited-state lifetimes of several 4'-aryl-substituted terpyridyl complexes of ruthenium(II) are reported. Synthetic tuning is explored within three conceptual series of complexes. The first series explores the impact of introducing a strong σ-donating 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine (tbtpy) opposite to an arylated terpyridine ligand 4'-(4-methylphenyl)-2,2':6',2″-terpyridine (ttpy). It is found that (3)MLCT (triplet metal-to-ligand charge-transfer state) stabilization concomitant with (3)MC (triplet metal-centered state) destabilization in the heteroleptic parent complex [Ru(ttpy)(tbtpy)](2+) leads to an extended excited-state lifetime relative to the structurally related bis-homoleptic species [Ru(ttpy)2](2+). The second series explores the impact of introducing a carboxylic acid or a methyl ester moiety at the para-position of the arylterpyridyl ligand (R1 = R2 = H) within heteroleptic complexes as a platform for future semiconductor attachment studies. This substitution leads to further lifetime enhancements, understood as arising from (3)MLCT stabilization. Such complexes are referred to as [Ru(1)(tbtpy)](2+) (for the acid at R3) and [Ru(1')(tbtpy)](2+) (for the ester at R3). In the final series, methyl substituents are sequentially added at the R1 and R2 positions for both the acid ([Ru(2)(tbtpy)](2+) and [Ru(3)(tbtpy)](2+)) and ester ([Ru(2')(tbtpy)](2+) and [Ru(3')(tbtpy)](2+)) analogues to eventually explore dynamical electron transfer coupling at dye/semiconductor interfaces. In these complexes, sequential addition of steric bulk decreases excited state lifetimes. This can be understood to arise primarily from the increase of the (3)MLCT level, as excited-state electron delocalization is limited by inter-ring twisting in the lower-energy arylated ligand. The introduction of a dimethylated sterically encumbered ligand lead to a notable 14-fold increase in knr from [Ru(1')(tbtpy)](2+) to [Ru(3')(tbtpy)](2+) (or [Ru(1)(tbtpy)](2+) to [Ru(3)(tbtpy)](2+)).
Collapse
Affiliation(s)
- Karen E Spettel
- Department of Chemistry and Biochemistry, University of Colorado-Boulder , Boulder, Colorado 80309, United States
| | | |
Collapse
|
19
|
Dixon IM, Khan S, Alary F, Boggio-Pasqua M, Heully JL. Probing the photophysical capability of mono and bis(cyclometallated) Fe(ii) polypyridine complexes using inexpensive ground state DFT. Dalton Trans 2014; 43:15898-905. [DOI: 10.1039/c4dt01939c] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
20
|
King AW, McClure BA, Jin Y, Rack JJ. Investigating the effects of solvent on the ultrafast dynamics of a photoreversible ruthenium sulfoxide complex. J Phys Chem A 2014; 118:10425-32. [PMID: 25137451 DOI: 10.1021/jp504078g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The photochromic complex [Ru(bpy)2(pySO)](2+) [pySO is 2-(isopropylsulfinylmethyl)pyridine] undergoes wavelength specific, photoreversible S → O and O → S linkage isomerizations. Irradiation of the ground state S-bonded complex with blue light produces the O-bonded isomer, while irradiation of the O-bonded isomer with green light produces the S-bonded isomer. Furthermore, isomerization time constants are solvent-dependent. Ultrafast transient absorption spectroscopy has been employed to investigate the relaxation processes that lead to S → O isomerization in 1,2-dichloroethane, propylene carbonate, and ethylene glycol. The isomerization is most rapid in 1,2-dichloroethane and slowest in ethylene glycol. Photochemical reversion of the O-bonded isomer in propylene carbonate has further been investigated and indicates similar relaxation or isomerization kinetics, though the excited states that lead to isomerization are distinct between the S- and O-bonded isomers.
Collapse
Affiliation(s)
- Albert W King
- Nanoscale and Quantum Phenomena Institute, Department of Chemistry and Biochemistry, Ohio University , Athens, Ohio 45701, United States
| | | | | | | |
Collapse
|
21
|
Göttle AJ, Alary F, Dixon IM, Heully JL, Boggio-Pasqua M. Unravelling the S → O linkage photoisomerization mechanisms in cis- and trans-[Ru(bpy)2(DMSO)2](2+) using density functional theory. Inorg Chem 2014; 53:6752-60. [PMID: 24932513 DOI: 10.1021/ic500546q] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A mechanistic study of the intramolecular S → O linkage photoisomerization in the cis and trans isomers of [Ru(bpy)2(DMSO)2](2+) was performed using density functional theory. This study reveals that for the cis isomer the linkage photoisomerization of the two DMSO ligands occurs sequentially in the lowest triplet excited state and can either be achieved by a one-photon or by a two-photon mechanism. A mechanistic picture of the S → O photoisomerization of the trans isomer is also proposed. This work especially highlights that both adiabatic and nonadiabatic processes are involved in these mechanisms and that their coexistence is responsible for the rich photophysics and photochemical properties observed experimentally for the studied complexes. The different luminescent behavior experimentally observed at low temperature between the cis and trans isomers is rationalized based on the peculiarity of the topology of the triplet excited-state potential energy surfaces.
Collapse
Affiliation(s)
- Adrien J Göttle
- Laboratoire de Chimie et Physique Quantiques, UMR 5626 CNRS/Université Paul Sabatier-Toulouse III , 118 route de Narbonne, 31062 Toulouse, France
| | | | | | | | | |
Collapse
|
22
|
Pal AK, Hanan GS. Design, synthesis and excited-state properties of mononuclear Ru(ii) complexes of tridentate heterocyclic ligands. Chem Soc Rev 2014; 43:6184-97. [DOI: 10.1039/c4cs00123k] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
23
|
Vieuxmaire OPJ, Piau RE, Alary F, Heully JL, Sutra P, Igau A, Boggio-Pasqua M. Theoretical Investigation of Phosphinidene Oxide Polypyridine Ruthenium(II) Complexes: Toward the Design of a New Class of Photochromic Compounds. J Phys Chem A 2013; 117:12821-30. [DOI: 10.1021/jp408898n] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Olivier P. J. Vieuxmaire
- Laboratoire
de Chimie et Physique Quantiques—IRSAMC, CNRS et Université de Toulouse, 118 route de Narbonne, 31062 Toulouse Cedex 09, France
| | - Rémi E. Piau
- Laboratoire
de Chimie et Physique Quantiques—IRSAMC, CNRS et Université de Toulouse, 118 route de Narbonne, 31062 Toulouse Cedex 09, France
| | - Fabienne Alary
- Laboratoire
de Chimie et Physique Quantiques—IRSAMC, CNRS et Université de Toulouse, 118 route de Narbonne, 31062 Toulouse Cedex 09, France
| | - Jean-Louis Heully
- Laboratoire
de Chimie et Physique Quantiques—IRSAMC, CNRS et Université de Toulouse, 118 route de Narbonne, 31062 Toulouse Cedex 09, France
| | - Pierre Sutra
- LCC
(Laboratoire de Chimie de Coordination), CNRS, 205 route de
Narbonne, F-31077 Toulouse, France
- UPS, INPT, LCC, Université de Toulouse, F-31062 Toulouse, France
| | - Alain Igau
- LCC
(Laboratoire de Chimie de Coordination), CNRS, 205 route de
Narbonne, F-31077 Toulouse, France
- UPS, INPT, LCC, Université de Toulouse, F-31062 Toulouse, France
| | - Martial Boggio-Pasqua
- Laboratoire
de Chimie et Physique Quantiques—IRSAMC, CNRS et Université de Toulouse, 118 route de Narbonne, 31062 Toulouse Cedex 09, France
| |
Collapse
|
24
|
Dixon IM, Alary F, Boggio-Pasqua M, Heully JL. The (N4C2)2– Donor Set as Promising Motif for Bis(tridentate) Iron(II) Photoactive Compounds. Inorg Chem 2013; 52:13369-74. [DOI: 10.1021/ic402453p] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Isabelle M. Dixon
- Laboratoire de Chimie et Physique
Quantiques, UMR 5626, CNRS/Université Paul Sabatier-Toulouse III, 118 route de Narbonne, Toulouse, France
| | - Fabienne Alary
- Laboratoire de Chimie et Physique
Quantiques, UMR 5626, CNRS/Université Paul Sabatier-Toulouse III, 118 route de Narbonne, Toulouse, France
| | - Martial Boggio-Pasqua
- Laboratoire de Chimie et Physique
Quantiques, UMR 5626, CNRS/Université Paul Sabatier-Toulouse III, 118 route de Narbonne, Toulouse, France
| | - Jean-Louis Heully
- Laboratoire de Chimie et Physique
Quantiques, UMR 5626, CNRS/Université Paul Sabatier-Toulouse III, 118 route de Narbonne, Toulouse, France
| |
Collapse
|