Singlet Excited State Dynamics of Tetrakis(4-N-methylpyridyl)porphine Associated with DNA Nucleotides

1997 ◽  
Vol 101 (8) ◽  
pp. 1444-1450 ◽  
Author(s):  
Ravi Jasuja ◽  
David M. Jameson ◽  
Coreen K. Nishijo ◽  
Randy W. Larsen
2006 ◽  
Vol 110 (26) ◽  
pp. 12843-12847 ◽  
Author(s):  
Thomas Gustavsson ◽  
Nilmoni Sarkar ◽  
Elodie Lazzarotto ◽  
Dimitra Markovitsi ◽  
Vincenzo Barone ◽  
...  

2006 ◽  
Vol 429 (4-6) ◽  
pp. 551-557 ◽  
Author(s):  
Thomas Gustavsson ◽  
Nilmoni Sarkar ◽  
Elodie Lazzarotto ◽  
Dimitra Markovitsi ◽  
Roberto Improta

2005 ◽  
Vol 109 (20) ◽  
pp. 4431-4436 ◽  
Author(s):  
Lluís Blancafort ◽  
Boiko Cohen ◽  
Patrick M. Hare ◽  
Bern Kohler ◽  
Michael A. Robb

Author(s):  
John A. Clark ◽  
Rafał Orłowski ◽  
James B. Derr ◽  
Eli M. Espinoza ◽  
Daniel T. Gryko ◽  
...  

AbstractIn the first two decades of the XXI century, corroles have emerged as an important class of porphyrinoids for photonics and biomedical photonics. In comparison with porphyrins, corroles have lower molecular symmetry and higher electron density, which leads to uniquely complementary properties. In macrocycles of free-base corroles, for example, three protons are distributed among four pyrrole nitrogens. It results in distinct tautomers that have different thermodynamic energies. Herein, we focus on the excited-state dynamics of a corrole modified with l-phenylalanine. The tautomerization in the singlet-excited state occurs in the timescales of about 10–100 picoseconds and exhibits substantial kinetic isotope effects. It, however, does not discernably affect nanosecond deactivation of the photoexcited corrole and its basic photophysics. Nevertheless, this excited-state tautomerization dynamics can strongly affect photoinduced processes with comparable or shorter timescales, considering the 100-meV energy differences between the tautomers in the excited state. The effects on the kinetics of charge transfer and energy transfer, initiated prior to reaching the equilibrium thermalization of the excited-state tautomer population, can be indeed substantial. Such considerations are crucially important in the design of systems for artificial photosynthesis and other forms of energy conversion and charge transduction.


2019 ◽  
Author(s):  
Matthew M. Brister ◽  
Carlos Crespo-Hernández

<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>


2019 ◽  
Author(s):  
Gergely Samu ◽  
R.A. Scheidt ◽  
A. Balog ◽  
C. Janáky ◽  
P.V. Kamat

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