Guest and solvent modulated photo-driven charge separation and triplet generation in a perylene bisimide cyclophane

Intramolecular charge separation and enhanced spin orbit coupling explain the weak fluorescence of a T-shaped dyad comprising two strong fluorophores.

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Folding-Induced Modulation of Excited-State Dynamics in an Oligophenylene-Ethynylene-Tethered Spiral Perylene Bisimide Aggregate

ChemPhysChem ◽

10.1002/cphc.201500156 ◽

2015 ◽

Vol 16 (8) ◽

pp. 1757-1767 ◽

Cited By ~ 11

Author(s):

Minjung Son ◽

Benjamin Fimmel ◽

Volker Dehm ◽

Frank Würthner ◽

Dongho Kim

Keyword(s):

Excited State ◽

Excited State Dynamics ◽

Perylene Bisimide

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meso-Arylethynyl subporphyrins as efficient and tunable photo-induced electron transfer units

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424617500249 ◽

2017 ◽

Vol 21 (02) ◽

pp. 152-157 ◽

Cited By ~ 4

Author(s):

Won-Young Cha ◽

Juwon Oh ◽

Masaaki Kitano ◽

Atsuhiro Osuka ◽

Dongho Kim

Keyword(s):

Electron Transfer ◽

Excited State ◽

Fluorescence Quenching ◽

Charge Separation ◽

Solvent Polarity ◽

Enhanced Fluorescence ◽

Excited State Dynamics ◽

Photo Induced Electron Transfer

Excited state dynamics of meso-arylethynyl-substituted subporphyrins can be tuned by 4-substituent at the arylethynyl group and solvent polarity. In polar acetonitrile, phenylethynyl subporphyrin 1 exhibited enhanced fluorescence, while (4-dimethylaminophenyl)ethynyl subporphyrin 2 showed red-shifted fluorescence from its charge-separated state and (4-nitrophenyl)ethynyl subporphyrin 3 displayed efficient fluorescence quenching due to charge separation.

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ULTRAFAST XUV SPECTROSCOPY TO PROBE CONICAL INTERSECTIONS AND EXCITED STATE DYNAMICS

Proceedings of the 74th International Symposium on Molecular Spectroscopy ◽

10.15278/isms.2019.wk01 ◽

2019 ◽

Author(s):

Arvinder Sandhu

Keyword(s):

Excited State ◽

Conical Intersections ◽

Excited State Dynamics ◽

Xuv Spectroscopy

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Excited-State Dynamics in the RNA Nucleotide Uridine 5’-Monophosphate Investigated by Femtosecond Broadband Transient Absorption Spectroscopy

10.26434/chemrxiv.7860023 ◽

2019 ◽

Author(s):

Matthew M. Brister ◽

Carlos Crespo-Hernández

Keyword(s):

Excited State ◽

Excited States ◽

Ground State ◽

Transient Absorption ◽

Electronic Energy ◽

Transient Absorption Spectroscopy ◽

Electronic Relaxation ◽

Vibrationally Excited ◽

Excited State Dynamics ◽

Π State

Damage to RNA from ultraviolet radiation induce chemical modifications to the nucleobases. Unraveling the excited states involved in these reactions is essential, but investigations aimed at understanding the electronic-energy relaxation pathways of the RNA nucleotide uridine 5’-monophosphate (UMP) have not received enough attention. In this Letter, the excited-state dynamics of UMP is investigated in aqueous solution. Excitation at 267 nm results in a trifurcation event that leads to the simultaneous population of the vibrationally-excited ground state, a longlived 1nOπ* state, and a receiver triplet state within 200 fs. The receiver state internally convert to the long-lived 3ππ* state in an ultrafast time scale. The results elucidate the electronic relaxation pathways and clarify earlier transient absorption experiments performed for uracil derivatives in solution. This mechanistic information is important because long-lived nπ* and ππ* excited states of both singlet and triplet multiplicities are thought to lead to the formation of harmful photoproducts.

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