The Visible Absorption Spectrum of Bromine in Solution

1948 ◽  
Vol 1 (4) ◽  
pp. 472 ◽  
Author(s):  
NS Bayliss ◽  
ARH Cole ◽  
BG Green
Keyword(s):  
Absorption Spectrum ◽  
Sulphuric Acid ◽  
Room Temperature ◽  
Vibrational Energy ◽  
Energy Levels ◽  
Visible Absorption Spectrum ◽  
Visible Absorption ◽  
Solvent Molecules ◽  
Vibrational Energy Levels ◽  
Associated Solvents

The visible absorption spectrum of bromine was measured in n-hexane (a normal solvent) and in concentrated sulphuric acid (at room temperature and at -70� C.), phosphoric acid, and ethanol (at -70� C.) as associated solvents. The absorption continuum at 4150 A. in the gas is displaced slightly to the red in n-hexane although other normal solvents may displace it to the violet. The displacement to the violet is greater in associated solvents, ranging from 650 cm.-l in sulphuric acid to over 2000 cm.-1 in ethanol. The displacement in sulphuric acid glass at -70� C, is nearly double the value at 18� C. The displacements in associated solvents are explained in terms of the effect of the semi-rigid cage of solvent molecules surrounding each bromine molecule, and the assumption of " solvates " is unnecessary and undesirable. The spectra in solution are between 40 and 70 per cent. more intense than in the gas, about double the increase that would be predicted by Chako's treatment of the effect of Lorentz-Lorenz forces. The differences in the shape and Emax between solutions in sulphuric acid at 18� C. and at -70� C. are due to the different statistical distribution of bromine molecules between the vibrational energy levels.

The visible absorption spectrum of 1,2-cyclobutanedione in the gas phase

1986 ◽  
Vol 64 (11) ◽  
pp. 2152-2161 ◽  
Author(s):  
R. A. Back ◽  
J. M. Parsons
Keyword(s):  
Absorption Spectrum ◽  
Gas Phase ◽  
Singlet State ◽  
Energy Levels ◽  
Vibrational Structure ◽  
Visible Absorption Spectrum ◽  
Excited Singlet ◽  
Bending Vibration ◽  
Visible Absorption ◽  
Out Of Plane

The visible absorption spectrum of 1,2-cyclobutanedione has been measured in the gas phase at wavelengths between 4000 and 5100 Å. The absorption is attributed to the allowed π* ← n+, 1B1 ← 1A1 transition corresponding to the first excited singlet state. The spectrum shows a complex well-resolved vibrational structure which has been analysed, with some 125 bands measured and assigned. The bands at the longer wavelengths show sharp rotational fine structure, not yet analysed. The strongest band in the spectrum at 4933 Å has been assigned as the 0–0 band, while a band almost as strong at 4820 Å is attributed to excitation of one quantum of [Formula: see text], the a2 out-of-plane carbonyl bending vibration, and it is suggested that this band owes its intensity to vibronic coupling. A number of symmetric vibrations are also excited in the spectrum, but with no long progressions. Sequence bands running to the blue with an interval of about 72 cm−1 are prominent throughout the spectrum, and are assigned to v13, the a2 ring-twisting vibration. Other hot bands were also observed involving v13 which permitted estimation of energy levels for this vibration both in the ground state and the excited state. The infrared spectrum was also measured and analysed in the gas phase between 600 and 4000 cm−1, and 14 bands were assigned to fundamental vibrations; some of these assignments, at the lower frequencies, are uncertain.

ABSORPTION SPECTRUM OF THE CCN RADICAL

1965 ◽  
Vol 43 (10) ◽  
pp. 1795-1830 ◽  
Author(s):  
A. J. Merer ◽  
D.N. Travis
Keyword(s):  
Absorption Spectrum ◽  
Transient Absorption ◽  
Flash Photolysis ◽  
Vibrational Energy ◽  
Energy Levels ◽  
Transient Absorption Spectrum ◽  
Molecular Constants ◽  
Angular Momenta ◽  
Show Evidence ◽  
Vibrational Energy Levels

A new transient absorption spectrum, attributed to the CCN free radical, has been discovered in the flash photolysis of diazoacetonitrile, HC(CN)N2; three electronic transitions, between 3 500 Å and 4 700 Å, have been photographed for both CC14N and CC15N. The ground state of the radical is a 2Πr electronic state, and the three excited states observed are A2Δ, B2Σ−, and C2Σ+. The 2Π and 2Δ states show evidence of Renner–Teller interaction between the vibrational and electronic angular momenta, an effect not observed previously for 2Δ states. Theoretical expressions for the vibrational energy levels of linear triatomic molecules in 2Δ electronic states have been derived, in terms of a parameter η associated with the quartic terms in the potential energy. They are compared with the observed pattern in the ν2 = 1 level of the A2Δ state. The principal molecular constants for CC14N (in cm−1) are as follows:[Formula: see text]

scholarly journals Research progress in the effects of terahertz waves on biomacromolecules

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Liu Sun ◽  
Li Zhao ◽  
Rui-Yun Peng
Keyword(s):  
Vibrational Energy ◽  
Rapid Development ◽  
Energy Levels ◽  
Basic Research ◽  
Research Progress ◽  
Biological Macromolecules ◽  
Terahertz Waves ◽  
Terahertz Spectrum ◽  
Biomedical Field ◽  
Vibrational Energy Levels

AbstractWith the rapid development of terahertz technologies, basic research and applications of terahertz waves in biomedicine have attracted increasing attention. The rotation and vibrational energy levels of biomacromolecules fall in the energy range of terahertz waves; thus, terahertz waves might interact with biomacromolecules. Therefore, terahertz waves have been widely applied to explore features of the terahertz spectrum of biomacromolecules. However, the effects of terahertz waves on biomacromolecules are largely unexplored. Although some progress has been reported, there are still numerous technical barriers to clarifying the relation between terahertz waves and biomacromolecules and to realizing the accurate regulation of biological macromolecules by terahertz waves. Therefore, further investigations should be conducted in the future. In this paper, we reviewed terahertz waves and their biomedical research advantages, applications of terahertz waves on biomacromolecules and the effects of terahertz waves on biomacromolecules. These findings will provide novel ideas and methods for the research and application of terahertz waves in the biomedical field.

scholarly journals MARVEL: measured active rotational–vibrational energy levels

2007 ◽  
Vol 245 (2) ◽  
pp. 115-125 ◽  
Author(s):  
Tibor Furtenbacher ◽  
Attila G. Császár ◽  
Jonathan Tennyson
Keyword(s):  
Vibrational Energy ◽  
Energy Levels ◽  
Vibrational Energy Levels

scholarly journals Vibrational band-structures caused by internal rotations of the boron Wankel rotor B11−

RSC Advances ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 3613-3621
Author(s):  
Yonghong Xu ◽  
Huihui Wang ◽  
Yonggang Yang ◽  
Changyong Li ◽  
Liantuan Xiao ◽  
...  
Keyword(s):  
Vibrational Energy ◽  
Energy Levels ◽  
Vibrational Band ◽  
Spectral Broadening ◽  
Band Structures ◽  
Internal Rotations ◽  
Vibrational Energy Levels

The band structures of the vibrational energy levels of B11− lead to corresponding spectral broadening. The vibrational band-structures of planar boron rotors are caused by internal rotations.

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