1
|
Eastham K, Scattergood PA, Chu D, Boota RZ, Soupart A, Alary F, Dixon IM, Rice CR, Hardman SJO, Elliott PIP. Not All 3MC States Are the Same: The Role of 3MC cis States in the Photochemical N ∧N Ligand Release from [Ru(bpy) 2(N ∧N)] 2+ Complexes. Inorg Chem 2022; 61:19907-19924. [PMID: 36450138 DOI: 10.1021/acs.inorgchem.2c03146] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Ruthenium(II) complexes feature prominently in the development of agents for photoactivated chemotherapy; however, the excited-state mechanisms by which photochemical ligand release operates remain unclear. We report here a systematic experimental and computational study of a series of complexes [Ru(bpy)2(N∧N)]2+ (bpy = 2,2'-bipyridyl; N∧N = bpy (1), 6-methyl-2,2'-bipyridyl (2), 6,6'-dimethyl-2,2'-bipyridyl (3), 1-benzyl-4-(pyrid-2-yl)-1,2,3-triazole (4), 1-benzyl-4-(6-methylpyrid-2-yl)-1,2,3-triazole (5), 1,1'-dibenzyl-4,4'-bi-1,2,3-triazolyl (6)), in which we probe the contribution to the promotion of photochemical N∧N ligand release of the introduction of sterically encumbering methyl substituents and the electronic effect of replacement of pyridine by 1,2,3-triazole donors in the N∧N ligand. Complexes 2 to 6 all release the ligand N∧N on irradiation in acetonitrile solution to yield cis-[Ru(bpy)2(NCMe)2]2+, with resultant photorelease quantum yields that at first seem counter-intuitive and span a broad range. The data show that incorporation of a single sterically encumbering methyl substituent on the N∧N ligand (2 and 5) leads to a significantly enhanced rate of triplet metal-to-ligand charge-transfer (3MLCT) state deactivation but with little promotion of photoreactivity, whereas replacement of pyridine by triazole donors (4 and 6) leads to a similar rate of 3MLCT deactivation but with much greater photochemical reactivity. The data reported here, discussed in conjunction with previously reported data on related complexes, suggest that monomethylation in 2 and 5 sterically inhibits the formation of a 3MCcis state but promotes the population of 3MCtrans states which rapidly deactivate 3MLCT states and are prone to mediating ground-state recovery. On the other hand, increased photochemical reactivity in 4 and 6 seems to stem from the accessibility of 3MCcis states. The data provide important insights into the excited-state mechanism of photochemical ligand release by Ru(II) tris-bidentate complexes.
Collapse
Affiliation(s)
- Katie Eastham
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Paul A Scattergood
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.,Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Danny Chu
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Rayhaan Z Boota
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.,Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Adrien Soupart
- Laboratoire de Chimie et Physique Quantiques, UMR 5626 CNRS/Université Toulouse 3─Paul Sabatier, Université de Toulouse, 118 route de Narbonne, Toulouse 31062, France
| | - 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
| | - 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
| | - Craig R Rice
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Samantha J O Hardman
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - Paul I P Elliott
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.,Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| |
Collapse
|
3
|
Lavarda G, Bhattacharjee N, Brancato G, Torres T, Bottari G. Enabling Racemization of Axially Chiral Subphthalocyanine‐Tetracyanobutadiene‐Aniline Enantiomers by Triplet State Photogeneration. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202010133] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Giulia Lavarda
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
| | - Nicholus Bhattacharjee
- Scuola Normale Superiore Piazza dei Cavalieri 7 56126 Pisa Italy
- Istituto Nazionale di Fisica Nucleare Largo Pontecorvo 3 56100 Pisa Italy
| | - Giuseppe Brancato
- Scuola Normale Superiore Piazza dei Cavalieri 7 56126 Pisa Italy
- Istituto Nazionale di Fisica Nucleare Largo Pontecorvo 3 56100 Pisa Italy
| | - Tomás Torres
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
- IMDEA-Nanociencia c/Faraday 9, Campus de Cantoblanco 28049 Madrid Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem) Universidad Autónoma de Madrid 28049 Madrid Spain
| | - Giovanni Bottari
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
- IMDEA-Nanociencia c/Faraday 9, Campus de Cantoblanco 28049 Madrid Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem) Universidad Autónoma de Madrid 28049 Madrid Spain
| |
Collapse
|
4
|
Lavarda G, Bhattacharjee N, Brancato G, Torres T, Bottari G. Enabling Racemization of Axially Chiral Subphthalocyanine‐Tetracyanobutadiene‐Aniline Enantiomers by Triplet State Photogeneration. Angew Chem Int Ed Engl 2020; 59:21224-21229. [DOI: 10.1002/anie.202010133] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Indexed: 12/24/2022]
Affiliation(s)
- Giulia Lavarda
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
| | - Nicholus Bhattacharjee
- Scuola Normale Superiore Piazza dei Cavalieri 7 56126 Pisa Italy
- Istituto Nazionale di Fisica Nucleare Largo Pontecorvo 3 56100 Pisa Italy
| | - Giuseppe Brancato
- Scuola Normale Superiore Piazza dei Cavalieri 7 56126 Pisa Italy
- Istituto Nazionale di Fisica Nucleare Largo Pontecorvo 3 56100 Pisa Italy
| | - Tomás Torres
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
- IMDEA-Nanociencia c/Faraday 9, Campus de Cantoblanco 28049 Madrid Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem) Universidad Autónoma de Madrid 28049 Madrid Spain
| | - Giovanni Bottari
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
- IMDEA-Nanociencia c/Faraday 9, Campus de Cantoblanco 28049 Madrid Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem) Universidad Autónoma de Madrid 28049 Madrid Spain
| |
Collapse
|
5
|
Moll J, Wang C, Päpcke A, Förster C, Resch‐Genger U, Lochbrunner S, Heinze K. Green-Light Activation of Push-Pull Ruthenium(II) Complexes. Chemistry 2020; 26:6820-6832. [PMID: 32162414 PMCID: PMC7318647 DOI: 10.1002/chem.202000871] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/09/2020] [Indexed: 11/07/2022]
Abstract
Synthesis, characterization, electrochemistry, and photophysics of homo- and heteroleptic ruthenium(II) complexes [Ru(cpmp)2 ]2+ (22+ ) and [Ru(cpmp)(ddpd)]2+ (32+ ) bearing the tridentate ligands 6,2''-carboxypyridyl-2,2'-methylamine-pyridyl-pyridine (cpmp) and N,N'-dimethyl-N,N'-dipyridin-2-ylpyridine-2,6-diamine (ddpd) are reported. The complexes possess one (32+ ) or two (22+ ) electron-deficient dipyridyl ketone fragments as electron-accepting sites enabling intraligand charge transfer (ILCT), ligand-to-ligand charge transfer (LL'CT) and low-energy metal-to-ligand charge transfer (MLCT) absorptions. The latter peak around 544 nm (green light). Complex 22+ shows 3 MLCT phosphorescence in the red to near-infrared spectral region at room temperature in deaerated acetonitrile solution with an emission quantum yield of 1.3 % and a 3 MLCT lifetime of 477 ns, whereas 32+ is much less luminescent. This different behavior is ascribed to the energy gap law and the shape of the parasitic excited 3 MC state potential energy surface. This study highlights the importance of the excited-state energies and geometries for the actual excited-state dynamics. Aromatic and aliphatic amines reductively quench the excited state of 22+ paving the way to photocatalytic applications using low-energy green light as exemplified with the green-light-sensitized thiol-ene click reaction.
Collapse
Affiliation(s)
- Johannnes Moll
- Department of ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
| | - Cui Wang
- Division 1.2 BiophotonicsFederal Institute for Materials Research and Testing (BAM)Richard Willstätter-Straße 1112489BerlinGermany
- Institut für Chemie und BiochemieFreie Universität BerlinArnimallee 2214195BerlinGermany
| | - Ayla Päpcke
- Institute for Physics and Department of Life, Light and MatterUniversity of Rostock18051RostockGermany
| | - Christoph Förster
- Department of ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
| | - Ute Resch‐Genger
- Division 1.2 BiophotonicsFederal Institute for Materials Research and Testing (BAM)Richard Willstätter-Straße 1112489BerlinGermany
| | - Stefan Lochbrunner
- Institute for Physics and Department of Life, Light and MatterUniversity of Rostock18051RostockGermany
| | - Katja Heinze
- Department of ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
| |
Collapse
|
6
|
Asahara M, Kurimoto H, Nakamizu M, Hattori S, Shinozaki K. H/D solvent isotope effects on the photoracemization reaction of enantiomeric the tris(2,2′-bipyridine)ruthenium(ii) complex and its analogues. Phys Chem Chem Phys 2020; 22:6361-6369. [DOI: 10.1039/c9cp06758b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This work assessed solvent isotope effects on the photoracemization rate and emission lifetime for [Ru(bpy)3]2+ (bpy = 2,2′-bipyridine) in water.
Collapse
Affiliation(s)
- Masahiro Asahara
- Department of Materials Science
- Graduate School of Nanobioscience
- Yokohama City University
- Kanazawa-ku
- Japan
| | - Haruhiko Kurimoto
- Department of Materials Science
- Graduate School of Nanobioscience
- Yokohama City University
- Kanazawa-ku
- Japan
| | - Masato Nakamizu
- Department of Materials Science
- Graduate School of Nanobioscience
- Yokohama City University
- Kanazawa-ku
- Japan
| | - Shingo Hattori
- Department of Materials Science
- Graduate School of Nanobioscience
- Yokohama City University
- Kanazawa-ku
- Japan
| | - Kazuteru Shinozaki
- Department of Materials Science
- Graduate School of Nanobioscience
- Yokohama City University
- Kanazawa-ku
- Japan
| |
Collapse
|