Trapping intermediate MLCT states in low-symmetry {Ru(bpy)} complexes
The picosecond excited state dynamics of [Ru(tpm)(bpy)(NCS)]+ (RubNCS+) and [Ru(tpm)(bpy)(CN)]+ (RubCN+) (tpm = tris(1-pyrazolyl)methane, bpy = 2,2′-bipyridine) have been analyzed by means of transient absorption measurements and spectroelectrochemistry. Emissive 3MLCTs with (GS)HOMO(h+)-(GS)LUMO(e-...
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_20416520_v8_n11_p7434_Cadranel |
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todo:paper_20416520_v8_n11_p7434_Cadranel2023-10-03T16:37:57Z Trapping intermediate MLCT states in low-symmetry {Ru(bpy)} complexes Cadranel, A. Oviedo, P.S. Pieslinger, G.E. Yamazaki, S. Kleiman, V.D. Baraldo, L.M. Guldi, D.M. Photoexcitation Spectroelectrochemistry Bipyridines Electronic configuration Excited-state dynamics Kinetic barrier Picoseconds Ru(bpy) Time-scales Transient absorption measurements Excited states The picosecond excited state dynamics of [Ru(tpm)(bpy)(NCS)]+ (RubNCS+) and [Ru(tpm)(bpy)(CN)]+ (RubCN+) (tpm = tris(1-pyrazolyl)methane, bpy = 2,2′-bipyridine) have been analyzed by means of transient absorption measurements and spectroelectrochemistry. Emissive 3MLCTs with (GS)HOMO(h+)-(GS)LUMO(e-) configurations are the lowest triplet excited states regardless of whether 387 or 505 nm photoexcitation is used. 387 nm photoexcitation yields, after a few picoseconds, the emissive 3MLCTs. In contrast, 505 nm photoexcitation populates an intermediate excited state that we assign as a 3MLCT state, in which the hole sits in a metal-centered orbital of different symmetry, prior to its conversion to the emissive 3MLCTs. The disparities in terms of electronic configuration between the intermediate and the emissive 3MLCTs have two important consequences. On one hand, both states feature very different fingerprint absorptions in transient absorption measurements. On the other hand, the reconfiguration is impeded by a kinetic barrier. As such, the conversion is followed spectroscopically and kinetically on the 300 ps timescale. © 2017 The Royal Society of Chemistry. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_20416520_v8_n11_p7434_Cadranel |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Photoexcitation Spectroelectrochemistry Bipyridines Electronic configuration Excited-state dynamics Kinetic barrier Picoseconds Ru(bpy) Time-scales Transient absorption measurements Excited states |
| spellingShingle |
Photoexcitation Spectroelectrochemistry Bipyridines Electronic configuration Excited-state dynamics Kinetic barrier Picoseconds Ru(bpy) Time-scales Transient absorption measurements Excited states Cadranel, A. Oviedo, P.S. Pieslinger, G.E. Yamazaki, S. Kleiman, V.D. Baraldo, L.M. Guldi, D.M. Trapping intermediate MLCT states in low-symmetry {Ru(bpy)} complexes |
| topic_facet |
Photoexcitation Spectroelectrochemistry Bipyridines Electronic configuration Excited-state dynamics Kinetic barrier Picoseconds Ru(bpy) Time-scales Transient absorption measurements Excited states |
| description |
The picosecond excited state dynamics of [Ru(tpm)(bpy)(NCS)]+ (RubNCS+) and [Ru(tpm)(bpy)(CN)]+ (RubCN+) (tpm = tris(1-pyrazolyl)methane, bpy = 2,2′-bipyridine) have been analyzed by means of transient absorption measurements and spectroelectrochemistry. Emissive 3MLCTs with (GS)HOMO(h+)-(GS)LUMO(e-) configurations are the lowest triplet excited states regardless of whether 387 or 505 nm photoexcitation is used. 387 nm photoexcitation yields, after a few picoseconds, the emissive 3MLCTs. In contrast, 505 nm photoexcitation populates an intermediate excited state that we assign as a 3MLCT state, in which the hole sits in a metal-centered orbital of different symmetry, prior to its conversion to the emissive 3MLCTs. The disparities in terms of electronic configuration between the intermediate and the emissive 3MLCTs have two important consequences. On one hand, both states feature very different fingerprint absorptions in transient absorption measurements. On the other hand, the reconfiguration is impeded by a kinetic barrier. As such, the conversion is followed spectroscopically and kinetically on the 300 ps timescale. © 2017 The Royal Society of Chemistry. |
| format |
JOUR |
| author |
Cadranel, A. Oviedo, P.S. Pieslinger, G.E. Yamazaki, S. Kleiman, V.D. Baraldo, L.M. Guldi, D.M. |
| author_facet |
Cadranel, A. Oviedo, P.S. Pieslinger, G.E. Yamazaki, S. Kleiman, V.D. Baraldo, L.M. Guldi, D.M. |
| author_sort |
Cadranel, A. |
| title |
Trapping intermediate MLCT states in low-symmetry {Ru(bpy)} complexes |
| title_short |
Trapping intermediate MLCT states in low-symmetry {Ru(bpy)} complexes |
| title_full |
Trapping intermediate MLCT states in low-symmetry {Ru(bpy)} complexes |
| title_fullStr |
Trapping intermediate MLCT states in low-symmetry {Ru(bpy)} complexes |
| title_full_unstemmed |
Trapping intermediate MLCT states in low-symmetry {Ru(bpy)} complexes |
| title_sort |
trapping intermediate mlct states in low-symmetry {ru(bpy)} complexes |
| url |
http://hdl.handle.net/20.500.12110/paper_20416520_v8_n11_p7434_Cadranel |
| work_keys_str_mv |
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| _version_ |
1807324261217468416 |