Terahertz Measurements of Rotational Transitions in Vibrationally Excited States of N2O

1999 ◽  
Vol 196 (1) ◽  
pp. 131-138 ◽  
Author(s):  
I. Morino ◽  
K.M.T. Yamada ◽  
A.G. Maki
Keyword(s):  
Excited States ◽  
Vibrationally Excited ◽  
Rotational Transitions

Identification of a vibrationally excited level in methyl formate through microwave and far-infrared spectroscopy

2020 ◽  
Vol 98 (6) ◽  
pp. 551-554
Author(s):  
Kaori Kobayashi ◽  
Yusuke Sakai ◽  
Masaharu Fujitake ◽  
Dennis W. Tokaryk ◽  
Brant E. Billinghurst ◽  
...  
Keyword(s):  
Excited States ◽  
Ground State ◽  
Methyl Formate ◽  
Excited Level ◽  
Far Infrared ◽  
Infrared Region ◽  
Far Infrared Spectroscopy ◽  
Interstellar Molecule ◽  
Vibrationally Excited ◽  
Rotational Transitions

Methyl formate (HCOOCH3) is an important interstellar molecule. More than 1000 rotational transitions including those from the ground state, torsionally excited states, and of its isotopologues have been observed towards several astrophysical sources. The laboratory spectra of methyl formate in the microwave spectral region contain many unassigned transitions and many of them are likely to be due to rotational transitions in the low-lying excited states. We report the laboratory identification of new rotational transitions in the COC deformation (ν12) excited state. The identification was made possible by combining the microwave data with rotation–vibration spectra taken in the far-infrared region at the Canadian Light Source synchrotron.

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>

scholarly journals The Microwave Spectrum of 3,4-Dihydro-1,2-Pyran

1985 ◽  
Vol 40 (9) ◽  
pp. 913-919
Author(s):  
Juan Carlos López ◽  
José L. Alonso
Keyword(s):  
Dipole Moment ◽  
Excited States ◽  
Ground State ◽  
Principal Axis ◽  
Microwave Spectrum ◽  
Average Intensity ◽  
Ring Conformation ◽  
Vibrationally Excited ◽  
Rotational Constants ◽  
Displacement Measurements

Abstract The rotational transitions of 3,4-dihydro-1,2-pyran in the ground state and six vibrationally excited states have been assigned. The rotational constants for the ground state (A = 5198.1847(24), B = 4747.8716(24) and C = 2710.9161(24) have been derived by fitting μa, μb and μc-type transitions. The dipole moment was determined from Stark displacement measurements to be 1.400(8) D with its principal axis components |μa| =1.240(2), |μb| = 0.588(10) and |μc| = 0.278(8) D. A model calculation to reproduce the ground state rotational constants indicates that the data are consistent with a twisted ring conformation. The average intensity ratio gives vibrational separations between the ground and excited states of the ring-bending and ring-twisting modes of ~ 178 and ~ 277 cm-1 respectively.

LABORATORY CHARACTERIZATION AND ASTROPHYSICAL DETECTION OF VIBRATIONALLY EXCITED STATES OF ETHYL CYANIDE

2013 ◽  
Vol 768 (1) ◽  
pp. 81 ◽  
Author(s):  
A. M. Daly ◽  
C. Bermúdez ◽  
A. López ◽  
B. Tercero ◽  
J. C. Pearson ◽  
...  
Keyword(s):  
Excited States ◽  
Vibrationally Excited ◽  
Laboratory Characterization

scholarly journals Millimeter-wave spectroscopy of HC5N in vibrationally excited states below 500 cm$\mathsf{^{-1}}$

2004 ◽  
Vol 425 (2) ◽  
pp. 767-772 ◽  
Author(s):  
K. M. T. Yamada ◽  
C. Degli Esposti ◽  
P. Botschwina ◽  
P. Förster ◽  
L. Bizzocchi ◽  
...  
Keyword(s):  
Excited States ◽  
Millimeter Wave ◽  
Vibrationally Excited ◽  
Millimeter Wave Spectroscopy
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