Probing the use of long lived intra-ligand π-π * excited states for photocatalytic systems: a study of the photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)]
We report the excited state photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)] (dppz-(CH3)2 = 11,12-dimethyl-dipyrido[3,2-a:2’,3’-c]phenazine) in CH3CN using timeresolved infrared (TRIR) and Fourier transform infrared (FTIR) spectroscopy. Excitation of the 1MLCT (metal-to-ligand charge tran...
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| Format: | Article |
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Elsevier
2017
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| Online Access: | https://eprints.nottingham.ac.uk/45837/ |
| _version_ | 1848797203397607424 |
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| author | Summers, Peter A. Calladine, James A. Ibrahim, Nasiru Kusumo, Kennedy P. Clark, Charlotte A. Sun, Xue-Z. Hamilton, Michelle L. Towrie, Michael McMaster, Jonathan Schröder, Martin George, Michael W. |
| author_facet | Summers, Peter A. Calladine, James A. Ibrahim, Nasiru Kusumo, Kennedy P. Clark, Charlotte A. Sun, Xue-Z. Hamilton, Michelle L. Towrie, Michael McMaster, Jonathan Schröder, Martin George, Michael W. |
| author_sort | Summers, Peter A. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | We report the excited state photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)] (dppz-(CH3)2 = 11,12-dimethyl-dipyrido[3,2-a:2’,3’-c]phenazine) in CH3CN using timeresolved infrared (TRIR) and Fourier transform infrared (FTIR) spectroscopy. Excitation of the 1MLCT (metal-to-ligand charge transfer) band of [ReCl(CO)3(dppz-(CH3)2)] populates a 3MLCT excited state which rapidly interconverts on a timescale < 1 ns to a long lived IL (intra-ligand) π-π* excited state with a lifetime of 190 (± 5) ns. In the presence of an electron donor (NEt3), the IL excited state of [ReCl(CO)3(dppz-(CH3)2)] can be reductively quenched to [ReCl(CO)3(dppz-(CH3)2)]− with the radical in the latter localised on the distal phenazine (phz) portion of the dppz ligand. The phz based electron in [ReCl(CO)3(dppz-(CH3)2)]− has minimal interaction with the rhenium metal centre which increases the stability of the photosensitiser in its reduced form. In non-dried, non-degassed CH3CN (1 M NEt3), [ReCl(CO)3(dppz-(CH3)2)]− shows no significant change in the carbonyl region of the IR spectrum for at least 2 hours during continuous photolysis. In addition, we investigate the use of [ReCl(CO)3(dppz-(CH3)2)]− to reduce the previously studied catalyst [NiFe2], with facile electron transfer from [ReCl(CO)3(dppz-(CH3)2)]− to form [NiFe2]–. |
| first_indexed | 2025-11-14T20:00:09Z |
| format | Article |
| id | nottingham-45837 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T20:00:09Z |
| publishDate | 2017 |
| publisher | Elsevier |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-458372020-05-04T18:34:24Z https://eprints.nottingham.ac.uk/45837/ Probing the use of long lived intra-ligand π-π * excited states for photocatalytic systems: a study of the photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)] Summers, Peter A. Calladine, James A. Ibrahim, Nasiru Kusumo, Kennedy P. Clark, Charlotte A. Sun, Xue-Z. Hamilton, Michelle L. Towrie, Michael McMaster, Jonathan Schröder, Martin George, Michael W. We report the excited state photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)] (dppz-(CH3)2 = 11,12-dimethyl-dipyrido[3,2-a:2’,3’-c]phenazine) in CH3CN using timeresolved infrared (TRIR) and Fourier transform infrared (FTIR) spectroscopy. Excitation of the 1MLCT (metal-to-ligand charge transfer) band of [ReCl(CO)3(dppz-(CH3)2)] populates a 3MLCT excited state which rapidly interconverts on a timescale < 1 ns to a long lived IL (intra-ligand) π-π* excited state with a lifetime of 190 (± 5) ns. In the presence of an electron donor (NEt3), the IL excited state of [ReCl(CO)3(dppz-(CH3)2)] can be reductively quenched to [ReCl(CO)3(dppz-(CH3)2)]− with the radical in the latter localised on the distal phenazine (phz) portion of the dppz ligand. The phz based electron in [ReCl(CO)3(dppz-(CH3)2)]− has minimal interaction with the rhenium metal centre which increases the stability of the photosensitiser in its reduced form. In non-dried, non-degassed CH3CN (1 M NEt3), [ReCl(CO)3(dppz-(CH3)2)]− shows no significant change in the carbonyl region of the IR spectrum for at least 2 hours during continuous photolysis. In addition, we investigate the use of [ReCl(CO)3(dppz-(CH3)2)]− to reduce the previously studied catalyst [NiFe2], with facile electron transfer from [ReCl(CO)3(dppz-(CH3)2)]− to form [NiFe2]–. Elsevier 2017-02-17 Article PeerReviewed Summers, Peter A., Calladine, James A., Ibrahim, Nasiru, Kusumo, Kennedy P., Clark, Charlotte A., Sun, Xue-Z., Hamilton, Michelle L., Towrie, Michael, McMaster, Jonathan, Schröder, Martin and George, Michael W. (2017) Probing the use of long lived intra-ligand π-π * excited states for photocatalytic systems: a study of the photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)]. Polyhedron, 123 . pp. 259-264. ISSN 0277-5387 Rhenium ; Time-resolved IR ; Photophysics ; Intra-ligand excited state ; Reductive quenching http://www.sciencedirect.com/science/article/pii/S0277538716305836?via%3Dihub doi:10.1016/j.poly.2016.11.005 doi:10.1016/j.poly.2016.11.005 |
| spellingShingle | Rhenium ; Time-resolved IR ; Photophysics ; Intra-ligand excited state ; Reductive quenching Summers, Peter A. Calladine, James A. Ibrahim, Nasiru Kusumo, Kennedy P. Clark, Charlotte A. Sun, Xue-Z. Hamilton, Michelle L. Towrie, Michael McMaster, Jonathan Schröder, Martin George, Michael W. Probing the use of long lived intra-ligand π-π * excited states for photocatalytic systems: a study of the photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)] |
| title | Probing the use of long lived intra-ligand π-π * excited states for photocatalytic systems: a study of the photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)] |
| title_full | Probing the use of long lived intra-ligand π-π * excited states for photocatalytic systems: a study of the photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)] |
| title_fullStr | Probing the use of long lived intra-ligand π-π * excited states for photocatalytic systems: a study of the photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)] |
| title_full_unstemmed | Probing the use of long lived intra-ligand π-π * excited states for photocatalytic systems: a study of the photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)] |
| title_short | Probing the use of long lived intra-ligand π-π * excited states for photocatalytic systems: a study of the photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)] |
| title_sort | probing the use of long lived intra-ligand π-π * excited states for photocatalytic systems: a study of the photophysics and photochemistry of [recl(co)3(dppz-(ch3)2)] |
| topic | Rhenium ; Time-resolved IR ; Photophysics ; Intra-ligand excited state ; Reductive quenching |
| url | https://eprints.nottingham.ac.uk/45837/ https://eprints.nottingham.ac.uk/45837/ https://eprints.nottingham.ac.uk/45837/ |