Molecular Road Map to Tuning Ground State Absorption and Excited State Dynamics of Long-Wavelength Absorbers

2017 ◽  
Vol 139 (46) ◽  
pp. 16946-16958 ◽  
Author(s):  
Yusong Bai ◽  
Jean-Hubert Olivier ◽  
Hyejin Yoo ◽  
Nicholas F. Polizzi ◽  
Jaehong Park ◽  
...  
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>


2009 ◽  
Vol 113 (42) ◽  
pp. 18358-18368 ◽  
Author(s):  
Nguyen Vân Anh ◽  
Felix Schlosser ◽  
Michiel M. Groeneveld ◽  
Ivo H. M. van Stokkum ◽  
Frank Würthner ◽  
...  

2015 ◽  
Vol 17 (32) ◽  
pp. 20715-20724 ◽  
Author(s):  
Tatu Kumpulainen ◽  
Bert H. Bakker ◽  
Albert M. Brouwer

Addition of a base to a solution of a photoacid in aprotic organic solvents results in the formation of ground-state complexes, which upon excitation dissociate via intermediate ion pair species.


1991 ◽  
Vol 244 ◽  
Author(s):  
Jau-Sheng Wang ◽  
Elias Snitzer ◽  
George H. Sigel

ABSTRACTThe results to be presented focus on the optimization of tellurite glass compositions which are suitable both for doping with erbium oxide as well as subsequent for fiber drawing. The laser related properties, such as fluorescence spectrum, lifetime, and optical transition cross sections will be presented. Judd-Ofelt parameters for erbium in the glasses have been exploited to predict fluorescence lifetime, excited state absorption(ESA), ground state absorption(GSA) and ground state fluorescence(GSF). For comparison, the absorption cross section, emission cross section, excited state absorption(ESA)/ground state absorption(GSA)(0.8μm pumping) and fluorescence terminating in the ground state(GSF)/excited state absorption(ESA) ratios are calculated for both Al2O3-SiO2 and tellurite glasses.


1989 ◽  
Vol 172 ◽  
Author(s):  
S. Zemon ◽  
G. Lambert ◽  
W. J. Miniscalco ◽  
L. J. Andrews ◽  
B. T. Hall

AbstractPump-excited-state-absorption (ESA) measurements on Er3+-doped phosphates, fluorophosphates, and silicate bulk glasses indicate that ESA cross sections are approximately equal to ground state absorption (GSA) cross sections in the 800-nm band. The oscillator strengths of the ESA and GSA bands are also approximately equal, in qualitative agreement with Judd-Ofelt calculations. Fluorozirconate samples were found to have substantial populations in the upper excited states for the measurement conditions used and ESA transitions originating from four excited states were identified. Fluorozirconate fiber amplifiers and lasers at 1.55 μm, therefore, would have decreased efficiency for 800-nm pumping.


1976 ◽  
Vol 54 (17) ◽  
pp. 1804-1814 ◽  
Author(s):  
J. W. C. Johns ◽  
D. A. Ramsay ◽  
S. C. Ross

The earlier analysis by Dressier and Ramsay of the [Formula: see text] absorption system of NH2 has been considerably extended at the long wavelength end of the spectrum. All the low-lying vibronic levels of the excited state have been identified up to ν2′ = 8. These levels are 010(K = 0), 020(K = 1), 030(K = 0,2), 040(K = 1,3), 050(K = 0,2,4), 060(K = 1,3,5), 070(K = 0,2,4,6), and 080(K = 1,3,5,7). Large perturbations (~ 200 cm−1) have been observed between some of these levels and high vibrational levels of the ground state. Accurate molecular constants have been obtained for the ground state and for the first level involving the bending vibration (ν2″ = 1).


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