Rotational structure in the NO2 absorption spectrum between 8170 and 8280 Å

1978 ◽  
Vol 56 (11) ◽  
pp. 1502-1512 ◽  
Author(s):  
A. J. Merer ◽  
K-E. J. Hallin
Keyword(s):  
Absorption Spectrum ◽  
Ground State ◽  
Infrared Region ◽  
Zero Order ◽  
Rotational Structure ◽  
High Dispersion ◽  
Detailed Understanding ◽  
Level Densities ◽  
Momentum Coupling

Three parallel-polarized sub-bands, lying in the region 8170–8280 Å in the absorption spectrum of NO2, have been analysed rotationally from high dispersion grating spectra. These sub-bands are assigned as perturbed K = 0, 1, and 4 sub-bands of the [Formula: see text], which appear in absorption because of vibrational momentum coupling with the [Formula: see text], 030–000 band, which lies 137 cm−1 lower in energy. It is shown that in the photographic infrared region of the NO2 spectrum the level densities in the interacting [Formula: see text] and F[Formula: see text] states are sufficiently low that it is possible to identify progressions of vibronically-induced transitions that in zero order would be within the ground state manifold. The implications for a more detailed understanding of the NO2 spectrum are discussed.

THE ABSORPTION SPECTRUM OF CF2

1967 ◽  
Vol 45 (7) ◽  
pp. 2355-2374 ◽  
Author(s):  
C. Weldon Mathews
Keyword(s):  
Absorption Spectrum ◽  
Electronic State ◽  
Ground State ◽  
Band System ◽  
Electronic States ◽  
Vibrational Structure ◽  
Rotational Structure ◽  
Transition Moment ◽  
High Dispersion ◽  
Parallel Type

The absorption spectrum of CF2 in the 2 500 Å region has been photographed at high dispersion, and the rotational structure of a number of bands has been analyzed. The analysis of the well-resolved subbands establishes that these are perpendicular- rather than parallel-type bands, as previously assigned. Further analysis shows that the upper and lower electronic states are of 1B1 and 1A1symmetries respectively, corresponding to a transition moment that is perpendicular to the plane of the molecule. In the upper electronic state, r0(CF) = 1.32 Å and [Formula: see text], while in the ground state, r0(CF) = 1.300 Å and [Formula: see text]. An investigation of the vibrational structure of the band system has shown that the vibrational numbering in ν2′ must be increased by one unit from earlier assignments, thus placing the 000–000 band near 2 687 Å (37 220 cm−1). A search between 1 300 and 8 500 Å showed two new band systems near 1 350 and 1 500 Å which have been assigned tentatively to the CF2 molecule.

The 7390 Å band of NO2, a vibronically-induced transition within the ground state manifold

1977 ◽  
Vol 55 (23) ◽  
pp. 2101-2112 ◽  
Author(s):  
K-E. J. Hallin ◽  
A. J. Merer
Keyword(s):  
Ground State ◽  
Vibrational Energy ◽  
Rotational Constant ◽  
Spin Rotation ◽  
High Dispersion ◽  
Vibrational Assignment ◽  
Rotation Parameters ◽  
Momentum Coupling ◽  
Parallel Band ◽  
Diabatic Representation

About 160 rotational lines in the region 7370–7410 Å in the electronic spectrum of NO2 have been assigned from high dispersion grating spectra. The lines form the K = 0,1, and 2 sub-bands of a perturbed parallel band where the upper state A rotational constant is about 17 cm−1. In a diabatic representation the band can be considered as a transition within the ground state manifold, which obtains its intensity by vibrational momentum coupling from a nearby band of the [Formula: see text] electronic transition; its vibrational assignment is 2 13 1 – 000. Comparison with the spectrum of 15NO2 shows that the nearby Ã2B2 level has quite a small amount of vibrational energy, which is not inconsistent with the assignment by Brand, Chan, and Hardwick that the (0, 0) band of the [Formula: see text] transition is at 8350 Å. The implications of the electron spin–rotation parameters and the intensity of the 7390 Å band are discussed.

scholarly journals Absorption Spectrum of Ni(II) Ions Doped in Magnesium Thallium Sulphate Hexahydrate

1992 ◽  
Vol 47 (7-8) ◽  
pp. 813-818 ◽  
Author(s):  
A. Venkata Subbaiah ◽  
J. Lakshmana Rao ◽  
R. Murali Krishna ◽  
S. V. J. Lakshman
Keyword(s):  
Absorption Spectrum ◽  
Liquid Nitrogen ◽  
Ground State ◽  
Near Infrared ◽  
Liquid Nitrogen Temperature ◽  
Infrared Region ◽  
Orbit Splitting ◽  
Excited Triplet ◽  
Spin Orbit Splitting ◽  
Near Infrared Region

Abstract The optical absorption spectrum of Ni(II) ions doped in magnesium thallium sulphate hexahydrate has been studied at room- and liquid nitrogen-temperature. The crystal shows characteristic absorption of Ni(II) ion in the visible and near infrared region. The observed bands are assigned as transitions from the ground state 3A2g(F) to various excited triplet and singlet levels of the Ni(II) ion in octahedral symmetry. The splitting in one of the bands at liquid nitrogen temperature has been explained to be due to spin-orbit splitting. All the observed band positions have been fitted with the parameters B, C, Dq, and ξ

Rotational analysis of the A0 + , B0 + ← X 1 Ʃ + systems of gaseous AgF

1971 ◽  
Vol 322 (1549) ◽  
pp. 243-249 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Dissociation Energy ◽  
Ground State ◽  
Rotational Structure ◽  
Rotational Analysis ◽  
Vibrational Levels

The absorption spectrum of AgF in the region 300.0 to 355.0 nm consists of a continuum centred at about 303.0 nm and two-band systems, A0 + , and B0 + ← X 1 Ʃ + . Rotational analyses have been made for all seven bands observed in the A─X system and of four bands in the B─X system, for both 107 AgF and 109 AgF. State A seems to have a very low dissociation energy and may possess only two stable vibrational levels. Lines at high J appear diffuse, indi­cating predissociation, perhaps by rotation. State B is also predissociated and only the bands with v ' ═ 0 show sharp rotational structure. The predissociating state is probably an Ω ═ 1 state which is the upper state of the 303.0 nm continuum. Constants for the ground state of 107 AgF are as follows: G v ═ 513.447 ± 0.009 ( v + ½) ─ 2.593 ± 0.002 ( v + ½) 2 B v ═ 0.26567 ─ 0.001901± 8 ( v + ½).

The absorption spectrum of the free SiH2 radical

1968 ◽  
Vol 46 (22) ◽  
pp. 2485-2490 ◽  
Author(s):  
I. Dubois
Keyword(s):  
Absorption Spectrum ◽  
Electronic State ◽  
Vibrational Level ◽  
Visible Region ◽  
Rotational Structure ◽  
Lower State ◽  
High Dispersion ◽  
Bending Vibration ◽  
Lower Electronic State

The absorption spectrum of SiH2 in the visible region has been photographed at high dispersion and the rotational structure of three bands has been analyzed. In the lower electronic state 1A1 the HSiH angle is 92° 5′ and the Si–H distance 1.516 Å, while in the upper state these parameters are 123° and 1.487 Å, respectively. The observed bands correspond to excitation of the bending vibration [Formula: see text] in the upper state. In the lower state, only one excited vibrational level, 010, has been observed, yielding [Formula: see text].

Correlation in the Ground State of He Atom

1981 ◽  
Vol 36 (3) ◽  
pp. 272-275 ◽  
Author(s):  
Subal Chandra Saha ◽  
Sankar Sengupta
Keyword(s):  
Ground State ◽  
Zero Order ◽  
Consistent Variation ◽  
Hartree Fock ◽  
Perturbation Procedure ◽  
Self Consistent ◽  
He Atom ◽  
Atomic Parameters

It is possible to reproduce the entire results of Pekeris et al. of different atomic parameters for the He atom by introducing (ll) type correlation in a self consistent variation perturbation procedure using the Hartree-Fock (HF) wavefunction as the zero-order wavefunction

scholarly journals Simultaneous Determination of Amlodipine and Valsartan

2011 ◽  
Vol 6 ◽  
pp. ACI.S7282 ◽  
Author(s):  
Nashwah Gadallah Mohamed
Keyword(s):  
Absorption Spectrum ◽  
Simultaneous Determination ◽  
Zero Order ◽  
Uv Spectrophotometry ◽  
Ratio Spectrum ◽  
First Derivative ◽  
Bulk Powder ◽  
Overlapped Peaks ◽  
Third Derivative

A spectrophotometric method was developed for simultaneous determination of amlodipine (Aml) and valsartan (Val) without previous separation. In this method amlodipine in methanolic solution was determined using zero order UV spectrophotometry by measuring its absorbency at 360.5 nm without any interference from valsartan. Valsartan spectrum in zero order is totally overlapped with that of amlodipine. First, second and third derivative could not resolve the overlapped peaks. The first derivative of the ratio spectra technique was applied for the measurement of valsartan. The ratio spectrum was obtained by dividing the absorption spectrum of the mixture by that of amlodipine, so that the concentration of valsartan could be determined from the first derivative of the ratio spectrum at 290 nm. Quantification limits of amlodipine and valsartan were 10-80 μg/ml and 20-180 μg/ml respectively. The method was successfully applied for the quantitative determination of both drugs in bulk powder and pharmaceutical formulation.

The electronic spectra of phenyl radicals

1965 ◽  
Vol 287 (1411) ◽  
pp. 457-470 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption Spectrum ◽  
Electronic Absorption ◽  
Ground State ◽  
Electronic Spectra ◽  
Flash Photolysis ◽  
Visible Region ◽  
Electronic Configuration ◽  
Vibrational Structure ◽  
Fundamental Frequencies

An electronic absorption spectrum, attributed to phenyl, has been observed in the visible region with origin at 18 908 cm -1 after flash photolysis of benzene and halogenobenzenes. Similar spectra of fluoro, chloro and bromo phenyl are observed after flash photolysis of disubstituted benzenes. The vibrational structure of the phenyl spectrum has been analysed in terms of two fundamental frequencies at 571 and 896 cm -1 which correspond to the e 2 g and a 1 g frequencies of the B 2 u state of benzene. The ground state of phenyl has a π 6 n electronic configuration and the observed transition is interpreted as 2 A 1 → 2 B 1 resulting from a π → n excitation.

scholarly journals Bacteriorhodopsin induces a light-scattering change in Halobacterium halobium.

1978 ◽  
Vol 79 (3) ◽  
pp. 657-662 ◽  
Author(s):  
C L Wey ◽  
P L Ahl ◽  
R A Cone
Keyword(s):  
Absorption Spectrum ◽  
Light Scattering ◽  
Near Infrared ◽  
Action Spectrum ◽  
Bright Light ◽  
Infrared Region ◽  
Halobacterium Halobium ◽  
Scattering Response ◽  
Near Infrared Region ◽  
Hypertonic Shock

When suspensions of Halobacterium halobium are exposed to bright light, the light-scattering properties of the bacteria change. This light-scattering response can produce a transmission decrease of about 1% throughout the red and near-infrared region. The action spectrum for the light-scattering response appropriately matches the absorption spectrum of bacteriorhodopsin. The response is eliminated by cyanide p-trifluoro-methoxyphenylhydrazone, a proton ionophore, and by triphenylmethylphosphonium, a membrane permanent cation. A mild hypertonic shock induces a similar light-scattering change, suggesting that bright light causes the bacteria to shrink about 1% in volume, thereby producing the light-scattering response.

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