Determination of Properties of Close-Lying Excited States of Olefins

Author(s):  
Robert J. Buenker ◽  
Vlasta Bonačić-Koutecký
Keyword(s):  
1974 ◽  
Vol 29 (8) ◽  
pp. 1213-1215 ◽  
Author(s):  
N. W. Larsen ◽  
B. P. Winnewisser

Rotational transitions of 16012C32S and 16013C32S in the ground vibrational state and of 16012C32S in several excited states have been accurately measured in the millimeter wave region for a minimum of four different J values. The analysis of the measured frequencies leads to rotational constants for the following vibrational states: 0 00 0 of 16O13C32S and 0 00 0, 0 1 1c 0, 0 1 1d 0, 0 20 0, 0 22c 0, 0 22d 0, 0 00 1 of 16O12C32S. Since the two components of the 0 22 0 transitions were resolved, an analysis of the l-type resonance was carried out and the interval 0 22 0 - 0 20 0 has been determined to be -4.63(10) cm-1. The result is in good agreement with the presently available determination of this level from vibrational spectra.


1992 ◽  
Vol 47 (6) ◽  
pp. 761-764 ◽  
Author(s):  
J. L. Alonso ◽  
N. Heineking ◽  
H. Dreizler ◽  
N. Heineking ◽  
H. Dreizler

AbstractThe microwave spectra of α-methyl-γ-butyrolactone and 2-methylcyclopentanone have been reinvestigated using microwave Fourier transform spectroscopy. A-E splittings due to internal rotation of the methyl group have been observed in the ground and several vibrationally excited states for both molecules. From an internal-axis-method analysis of these splittings, values of the methyl group internal rotation barrier of 2.61 kcal mol-1 for α-methyl-γ-butyrolactone and 2.41 kcal mol-1 for 2-methylcyclopentanone have been obtained.


2011 ◽  
Vol 20 (supp02) ◽  
pp. 200-209
Author(s):  
CÉSAR A. Z. VASCONCELLOS ◽  
DIMITER HADJIMICHEF ◽  
MÁRIO L. L. DA SILVA ◽  
MOISÉS RAZEIRA ◽  
ALEXANDRE MESQUITA ◽  
...  

We investigate relativistic bound states for a hypothetical light scalar gluino pair (gluinonium), in the framework of the covariant Bethe-Salpeter equation (BSE). In this paper, we derive, from the covariant BSE for a fermion-anti-fermion system, using charge conjugation, the corresponding bound-state equation for a gluino pair and we then formulate, for a static harmonic kernel, the coupled differential equations for the corresponding static Bethe-Salpeter amplitude. The steps of our approach then include a numerical solution of the Bethe-Salpeter amplitude for a two-body interaction consisting of scalar, pseudo-scalar, and four-vector components and the determination of the energy spectrum for the ground and the radially excited states of massive gluinonium. We found the energy spectrum and radial distributions of fundamental and excited states of gluinonium. The comparison of the values obtained in the extreme relativistic case with the corresponding values predicted by a harmonic oscillator potential model shows that there is good agreement between the two formulations. The predictions of the binding energy of glunionium in the non-relativistic model are however systematically higher.


2004 ◽  
Vol 121 (4) ◽  
pp. 1771-1781 ◽  
Author(s):  
S. Magnier ◽  
M. Aubert-Frécon ◽  
A. R. Allouche

2003 ◽  
Vol 07 (06) ◽  
pp. 452-456 ◽  
Author(s):  
Newton M. Barbosa Neto ◽  
Leonardo De Boni ◽  
José J. Rodrigues ◽  
Lino Misoguti ◽  
Cléber R. Mendonça ◽  
...  

Dynamic optical nonlinearities in free base tetrapyridylporphyrin ( H 2 TPyP ) solutions were investigated at 532 nm with the Z-scan technique. We observed a reverse saturable absorption process that was found to have a fast contribution related to the singlet population and a slow accumulative contribution arising from the triplet population. The optical excitations and subsequent relaxations can be interpreted with a five-energy-level diagram that allows determination of the excited states photophysical parameters such as triplet and singlet absorption cross-sections and the intersystem crossing time.


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