Vibrational Analysis of the 2800 Å Band System of para-Dibromobenzene

1972 ◽  
Vol 50 (12) ◽  
pp. 1402-1408 ◽  
Author(s):  
S. M. Japar
Keyword(s):  
Excited State ◽  
High Resolution ◽  
Ground State ◽  
Band System ◽  
Vibrational Analysis ◽  
Type A ◽  
Strong Type ◽  
Type B ◽  
Sequence Structure ◽  
Extensive Sequence

The 2800 Å band system of p-dibromobenzene has been photographed under high resolution and an extended vibrational analysis has been carried out. The analysis is not inconsistent with the assignment of the system to a 1B2u ← 1Ag transition, by analogy with other p-dihalogenated benzenes. The observed spectrum can be explained in terms of a number of strong type-B vibronic bands and a considerably smaller number of type-A vibronic bands. The extensive sequence structure is adequately accounted for, and can be related to observations on other halogenated benzene molecules. Thirteen ground state and nine excited state fundamental vibrational frequencies have been assigned.

Spectrum of AsS. I. Analysis of the A′2Π3/2–X2Π3/2 Band System

1971 ◽  
Vol 49 (10) ◽  
pp. 1249-1254 ◽  
Author(s):  
Midori Shimauchi
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Ground State ◽  
Band System ◽  
Vibrational Analysis ◽  
Quartz Tube ◽  
Rotational Analysis ◽  
Vibrational Constants

The emission spectrum of the AsS radical, excited in a quartz tube by a 2450 MHz oscillator, was photographed on a high resolution spectrograph from 2450 to 6900 Å. Seven bands around 6000 Å showing clear rotational structures were chosen for the first rotational analysis of the AsS spectrum. The bands were found to arise from a 2Π3/2–2Π3/2 transition. The rotational and vibrational constants of the two states derived from the present work are consistent with the previous vibrational analysis of the A′2Π3/2–X2Π3/2 system. The constants of the upper doublet component of the ground state, X2Π3/2, are ωe = 562.40 cm−1, ωexe = 2.02 cm−1, re = 2.0216 Å; the constants of the A′2Π3/2 state are ΔG′(1/2) = 403.37 cm−1, ν0,0 = 18 621.21 cm−1, re = 2.2500 Å.

High-resolution study of the υ9 fundamental band of trans-glyoxal

2001 ◽  
Vol 79 (2-3) ◽  
pp. 479-482 ◽  
Author(s):  
D B Braund ◽  
A RH Cole
Keyword(s):  
Excited State ◽  
High Resolution ◽  
Ground State ◽  
Type B ◽  
Rotational Constants ◽  
Fundamental Band ◽  
Stretching Vibration ◽  
Resolution Study

The spectrum of trans-glyoxal has been recorded at a resolution of about 0.004 cm–1 in the region from 2770 to 2900 cm–1. 1549 lines have been assigned to the type B band due to the υ9 (bu) fundamental (antisymmetric C–H stretching vibration). The ground-state rotational constants confirm earlier values and new constants are determined for the excited state of υ9. PACS No.: 33.20E

Spectroscopic studies on toluene and some deuterated derivatives. II. Electronic spectra

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1225-1235 ◽  
Author(s):  
Walter J. Balfour ◽  
Ram S. Ram
Keyword(s):  
Excited State ◽  
High Resolution ◽  
Ground State ◽  
Electronic Spectra ◽  
Spectroscopic Studies ◽  
Measured Data ◽  
Sequence Structure ◽  
State Information ◽  
Isotopic Species ◽  
Out Of Plane

The 266.7 nm absorption systems of toluene and seven deuterated isomers were observed at high resolution and analyses of their vibronic structure performed. All in-plane vibrations with ground-state frequencies less than 1000 cm−1 were identified from 0–1 hot bands. The frequencies agree well with data obtained from infrared and Raman studies. The corresponding vibrations were identified in the excited state. Information was also obtained on out-of-plane vibrations with ground-state frequencies less than 650 cm−1, since all of these are found to give sequence structure. A comparison of the measured data for the various isotopic species has enabled a consistent description of the excited state in toluene to be made. Problems associated with errors, ambiguities, and inconsistencies in previously published work have been addressed.

The analysis of a 2 A 1 - 2 B 1 electronic band system of the AsH 2 and AsD 2 radicals

1968 ◽  
Vol 305 (1481) ◽  
pp. 271-290 ◽  
Keyword(s):  
Excited State ◽  
Ground State ◽  
Flash Photolysis ◽  
Band System ◽  
Valence Angle ◽  
Electronic Transitions ◽  
Doublet State ◽  
Electronic Band ◽  
Asymmetric Rotor ◽  
Asymmetric Top

Two new band systems have been observed in absorption following flash photolysis of AsH 3 and AsD 3 , and are assigned to 2 A 1 - 2 B 1 electronic transitions of AsH 2 and AsD 2 . The origins of both systems are at 19905 cm -1 . The bands have the complex rotational structure associated with an asymmetric rotor. Rotational analyses have been carried out for three bands of the AsH 2 spectrum, leading to the following molecular parameters: ground state, r" 0 = 1.518 Å valence angle = 90° 44'; excited state, r' 0 = 1.48 Å, valence angle = 123° 0'. The parameters associated with rotation about the a inertial axis increase rapidly with increase in v' 2 . The spectrum shows doublet splittings of up to 41 cm -1 , and the excited state furnishes the first example of a doublet state of an asymmetric top molecule which shows substantial departures from Hund’s case ( b ).

scholarly journals Internal Rotation of the Methyl Group in the Electronically Excited State: o- and m-Toluidine

1987 ◽  
Vol 7 (2-4) ◽  
pp. 197-212 ◽  
Author(s):  
Katsuhiko Okuyama ◽  
Naohiko Mikami ◽  
Mitsuo Ito
Keyword(s):  
Excited State ◽  
Internal Rotation ◽  
Barrier Height ◽  
Ground State ◽  
Electronic Excitation ◽  
Vibrational Analysis ◽  
Fluorescence Excitation ◽  
Close Relationship ◽  
Electronically Excited ◽  
Dispersed Fluorescence

The fluorescence excitation and dispersed fluorescence spectra of jet-cooled o- and m-toluidine were observed. Vibrational analysis of the spectra provided us with the potentials for the internal rotation of the CH3 group in both ground and excited states. In o-toluidine, a large potential barrier to the internal rotation in the ground state is practically removed in the excited state. On the other hand, a nearly free internal rotation of the CH3 group in the ground state of m-toluidine gains a large barrier by the electronic excitation. The great change in the barrier height upon the electronic excitation is more remarkable than that found for fluorotoluene. A close relationship between the barrier height and the π electron density at the ring carbon atom was found, indicating the hyperconjugation as the origin of the barrier height in the absence of steric hindrance.

Spectrum of azulene. IV. Rotational analysis of the 0-0 band of the 3500 Ǻ transition

1968 ◽  
Vol 21 (12) ◽  
pp. 2835 ◽  
Author(s):  
AJ McHugh ◽  
DA Ramsay ◽  
IG Ross
Keyword(s):  
Fine Structure ◽  
Excited State ◽  
Type A ◽  
Resolving Power ◽  
Rotational Analysis ◽  
Type B ◽  
Rotational Constants ◽  
Multiple Line ◽  
Asymmetric Top ◽  
Low K

The bands of the 3500 Ǻ transition of azulene-do and azulene-ds show two unequal peaks 2.3 cm-l apart, followed by closely spaced fine structure. These bands have been analysed as type A bands of a planar, prolate asymmetric top. Rotational constants for both molecules in the excited state have been determined. The fine structure is due to multiple line coincidences in the high-J, low-K region of the qP branch. To each multiple line can be attributed a running number n = J+m, where m = J-K-1. Given sufficient resolving power, such "lines" should be rather commonly observed in type A and type B bands of large, planar, prolate molecules.

ULTRAVIOLET SPECTRA OF LiH AND LiD

1957 ◽  
Vol 35 (10) ◽  
pp. 1204-1214 ◽  
Author(s):  
R. Velasco
Keyword(s):  
Excited State ◽  
Ground State ◽  
Band System ◽  
Electronic States ◽  
High Dispersion ◽  
Dissociation Energies ◽  
Near Ultraviolet ◽  
Path Lengths ◽  
Vibrational Constants ◽  
Π State

The absorption spectra of LiH and LiD have been observed in the near ultraviolet with high dispersion and absorbing path lengths up to 16 meters. A new band system has been found in each molecule involving the ground state and a 1Π excited state. Rotational and vibrational analyses of this system have been carried out and rotational and vibrational constants for the upper state have been determined. The observed breaking off of the rotational structure of the bands of this B1Π—X1Σ+ system has been interpreted as due to predissociation by rotation. With this assumption very accurate dissociation limits of the B1Π state have been obtained. From these dissociation limits the dissociation energies of the three known electronic states of LiH and LiD have been calculated. In particular the dissociation energies (D0) of the ground states of LiH and LiD have been found to be 2.4288 ± 0.0002 ev. and 2.4509 ± 0.0010 ev., respectively.

Analyse Rotationnelle de la Bande (0,0) du Système Orange de ScO

1972 ◽  
Vol 50 (4) ◽  
pp. 395-403 ◽  
Author(s):  
R. Stringat ◽  
C. Athénour ◽  
J. L. Féménias
Keyword(s):  
Excited State ◽  
Hyperfine Interaction ◽  
Hyperfine Structure ◽  
Liquid Nitrogen ◽  
Hollow Cathode ◽  
Ground State ◽  
Type B ◽  
Hollow Cathode Lamp ◽  
Magnetic Hyperfine Interaction ◽  
Coupling Case

The orange system of ScO has been reanalyzed as a 2Π → 2Σ transition. We have observed all the branches which are compatible with the selection rules ΔJ = 0, ± 1. We have not detected the hyperfine structure in the excited state, the coupling case being therefore aβ. The magnetic hyperfine interaction inducing the ground state doubling is the only one which appears; it has been analyzed by other authors who have shown that the coupling case for this state is of the type bβS.The use of an alloy hollow-cathode lamp, cooled with liquid nitrogen, has enabled us to improve the frequency measurements. The values of the constants have been obtained by a method by which, working directly with the Hamiltonian, the introduction of each parameter can be justified. The study of the Λ doubling in 2Π3/2 and 2Π1/2 levels leads us to values of ξ and η very close to those predicted for a pure precession case.

Rotational and Vibrational Analysis of the First Singlet Transition (1B2 ← 1A1) of Isobenzofuran

1975 ◽  
Vol 53 (19) ◽  
pp. 1814-1824 ◽  
Author(s):  
M. J. Robey ◽  
I. G. Ross
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
Vibrational Analysis ◽  
Vibrational Structure ◽  
Rotational Structure ◽  
Type B ◽  
State Structure ◽  
Detailed Structure ◽  
Rotational Constants ◽  
Singlet Transition

The absorption spectrum of isobenzofuran vapor has been photographed at resolving powers in excess of 300 000. The vibrational structure is straightforward, involving totally symmetric vibrations only. The rotational structure of a band at 0 + 858 cm−1 has been analyzed as a type B band, leading to the assignment of the transition as 1B2 ← 1A1. The detailed structure of the band is described. The changes in the rotational constants are ΔA + 0.000124, ΔB −0.000122, and ΔC −0.00052 cm−1. A calculated excited state structure compatible with these results is proposed.

scholarly journals Spermatogonial morphology and kinetics during testis development in mice: a high-resolution light microscopy approach

Reproduction ◽  
2011 ◽  
Vol 142 (1) ◽  
pp. 145-155 ◽  
Author(s):  
Ana Luiza Drumond ◽  
Marvin L Meistrich ◽  
Hélio Chiarini-Garcia
Keyword(s):  
High Resolution ◽  
Light Microscopy ◽  
Type A ◽  
Absolute Number ◽  
Morphological Development ◽  
Type B ◽  
Developmental Sequence ◽  
Adult Mice ◽  
Pathological Conditions ◽  
Type A Spermatogonia

Despite the knowledge of spermatogonial biology in adult mice, spermatogonial development in immature animals has not been fully characterized. Thus, the aim of this study was to evaluate the ontogeny of the morphological development of the spermatogonial lineage in C57BL/6 mouse testis, using high-resolution light microscopy. Spermatogonial morphology, chronology, and absolute number were determined for different ages postpartum (pp). The morphology of spermatogonia in immature mice was similar to that of adult spermatogonia, although their nuclear diameter was slightly smaller. The A1 spermatogonia were first observed on day 2 pp, and only 24 h later, differentiating type A3 and A4 spermatogonia were observed in the seminiferous cords. This result indicated a shortening of the spermatogonial phase for immature mice of about ∼2.5 days when compared with adult mice and suggests that gonocytes and/or A1 spermatogonia could directly become A4 spermatogonia, skipping the developmental sequence of type A spermatogonia. These A4 spermatogonia are functional as they develop into type B spermatogonia by day 5 pp. At day 8 pp, while differentiation to spermatocytes begins, the Aund spermatogonia reach their maximal numbers, which are maintained through adulthood. The various details of the spermatogonial behavior in immature normal mice described in this study can be used as a baseline for further studies under experimental or pathological conditions.

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