Production and Excited State Dynamics of the Photorearranged Isomer of Benzyl Chloride and Its Methyl Derivatives Studied by Stepwise Two-Color Laser Excitation Transient Absorption and Time-Resolved Thermal Lensing Techniques

2005 ◽  
Vol 109 (26) ◽  
pp. 5825-5831 ◽  
Author(s):  
Mika Nagano ◽  
Tadashi Suzuki ◽  
Teijiro Ichimura ◽  
Tetsuo Okutsu ◽  
Hiroshi Hiratsuka ◽  
...  
Keyword(s):  
Excited State ◽  
Benzyl Chloride ◽  
Transient Absorption ◽  
Laser Excitation ◽  
Thermal Lensing ◽  
Time Resolved ◽  
Excited State Dynamics ◽  
Methyl Derivatives

scholarly journals Excited State Dynamics of Perylenediimide films with Isopropyl phenyl- and Undecane-Substitution

2020 ◽  
Author(s):  
Qiu-Shi Ma ◽  
Cheng-Wei Ju ◽  
Ruihua Pu ◽  
Wenjie Zhang ◽  
Xian Lin ◽  
...  
Keyword(s):  
Excited State ◽  
Excited States ◽  
Transient Absorption ◽  
Amorphous Film ◽  
Singlet Fission ◽  
Amorphous Films ◽  
Time Resolved ◽  
Excited State Dynamics ◽  
Coating Method ◽  
Time Resolved Photoluminescence

<p>The aggregation of Perylene Diimide (PDI) and its derivatives strongly depends on the molecular structure, and therefore has great impact on the excited states. By regulating the molecular stacking such as monomer, dimer, J- and/or H-aggregate, the formation of different excited states is adjustable and controllable. In this study, we have synthesized two kinds of PDI derivatives - undecane-substituted PDI (PDI-1) and diisopropylphenyl-substituted PDI (PDI-2), and the films are fabricated with spin-coating method. By employing photoluminescence (PL), time-resolved photoluminescence (TRPL) and transient absorption (TA) spectroscopy, the excited-state dynamics of two PDI amorphous films have been investigated systematically. The result reveals that both films have formed excimer after photoexcitation mainly due to the stronger electronic coupling among molecule aggregate in the amorphous film. It should be noted that the excited state dynamics in PDI-2 shows a singlet fission like process, which is evidenced by the appearance of triplet state absorption. This study provides the dynamics of excited state in amorphous PDI films, and pave the way for better understanding and adjusting the excited state of amorphous films. </p>

Excited State Dynamics of Perylenediimide films with Isopropyl phenyl- and Undecane-Substitution

2020 ◽  
Author(s):  
Qiu-Shi Ma ◽  
Cheng-Wei Ju ◽  
Ruihua Pu ◽  
Wenjie Zhang ◽  
Xian Lin ◽  
...  
Keyword(s):  
Excited State ◽  
Excited States ◽  
Transient Absorption ◽  
Amorphous Film ◽  
Singlet Fission ◽  
Amorphous Films ◽  
Time Resolved ◽  
Excited State Dynamics ◽  
Coating Method ◽  
Time Resolved Photoluminescence

<p>The aggregation of Perylene Diimide (PDI) and its derivatives strongly depends on the molecular structure, and therefore has great impact on the excited states. By regulating the molecular stacking such as monomer, dimer, J- and/or H-aggregate, the formation of different excited states is adjustable and controllable. In this study, we have synthesized two kinds of PDI derivatives - undecane-substituted PDI (PDI-1) and diisopropylphenyl-substituted PDI (PDI-2), and the films are fabricated with spin-coating method. By employing photoluminescence (PL), time-resolved photoluminescence (TRPL) and transient absorption (TA) spectroscopy, the excited-state dynamics of two PDI amorphous films have been investigated systematically. The result reveals that both films have formed excimer after photoexcitation mainly due to the stronger electronic coupling among molecule aggregate in the amorphous film. It should be noted that the excited state dynamics in PDI-2 shows a singlet fission like process, which is evidenced by the appearance of triplet state absorption. This study provides the dynamics of excited state in amorphous PDI films, and pave the way for better understanding and adjusting the excited state of amorphous films. </p>

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

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

<p></p><p> 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 <sup>1</sup>n<sub>O</sub>π* state, and a receiver triplet state within 200 fs. The receiver state internally convert to the long-lived <sup>3</sup>ππ* 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.</p><p></p>

Excited-state dynamics of guanosine in aqueous solution revealed by time-resolved photoelectron spectroscopy: experiment and theory

2015 ◽  
Vol 17 (47) ◽  
pp. 31978-31987 ◽  
Author(s):  
Franziska Buchner ◽  
Berit Heggen ◽  
Hans-Hermann Ritze ◽  
Walter Thiel ◽  
Andrea Lübcke
Keyword(s):  
Aqueous Solution ◽  
Excited State ◽  
Photoelectron Spectroscopy ◽  
Relaxation Dynamics ◽  
Time Resolved ◽  
Excited State Dynamics ◽  
Spectroscopy Experiment

Time-resolved photoelectron spectroscopy is performed on aqueous guanosine solution to study its excited-state relaxation dynamics.

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