n–π* Electronic Emission and Absorption Spectra of o-Fluorobenzaldehyde in Vapor Phase

1970 ◽  
Vol 24 (1) ◽  
pp. 36-41 ◽  
Author(s):  
M. P. Srivastava ◽  
I. S. Singh
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
Emission Spectrum ◽  
Absorption Spectra ◽  
Vapor Phase ◽  
Ground State ◽  
Emission And Absorption Spectra ◽  
Quartz Spectrograph

The electronic emission and absorption spectra of o-fluorobenzaldehyde have been studied. The emission spectrum recorded on a Fuess glass and a medium quartz spectrograph lies in the region 26 668–17 862 cm−1 and the absorption spectrum recorded on a Zeiss Q–24 medium quartz spectrograph lies in the region 30 995–24 610 cm−1. The O—O band has been observed at 26 337 cm−1. The C=O stretching frequency 1733 cm−1 in the ground state and 1355 cm−1 in the excited state is most intense and forms progressions of bands both in the emission and absorption spectra. The observed bands have been interpreted as combinations of the C=O stretching frequency and its multiples with other fundamentals. The transition involved is A‘–A’ ( n–π*).

n–π* Electronic Emission and Absorption Spectra of p-Fluorobenzaldehyde Vapor

1972 ◽  
Vol 26 (2) ◽  
pp. 278-282 ◽  
Author(s):  
M. P. Srivastava ◽  
I. S. Singh
Keyword(s):  
Excited State ◽  
Absorption Spectra ◽  
Vapor Phase ◽  
Infrared Spectra ◽  
Emission And Absorption Spectra ◽  
Stretching Vibration

The n–π* electronic emission and absorption spectra of p-fluorobenzaldehyde have been studied in vapor phase. Its Raman and infrared spectra have also been recorded. The spectra have been analyzed in terms of several ground and excited state fundamental vibrations. The C=0 stretching vibration is quite intense and dominates both the spectra. The transition has been ascribed to either A′- A′ or A′-A″ ( n–π*).

scholarly journals The absorption spectrum and fluorescence of mercury vapour

1905 ◽  
Vol 76 (512) ◽  
pp. 428-430 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Absorption Coefficient ◽  
Absorption Spectra ◽  
Quartz Glass ◽  
Mercury Vapour ◽  
Blue Colour ◽  
Water Jacket ◽  
Side Tube ◽  
Quartz Spectrograph

Having undertaken the investigation of the absorption spectra of metals in a state of vapour, the first substance examined was mercury, and as the results are interesting I have deemed it advisable to make them a separate communication to the Society. F. P. le Roux describes the vapour of mercury as having a bluish colour, and according to R. J. Strutt, it transmits a feeble steel-blue colour, but the absorption coefficient is small. Experimental.—The substance to be volatilised was contained in a flask of Heraeus’ quartz-glass, with a side tube to the neck from which the metal may be distilled and condensed. To the side tube a water-jacket is fitted through which a constant stream of water may be passed if necessary. The rays from the condensed spark of a pair of lead-cadmium and tin-cadmium electrodes were passed through the flask and on to a cylindrical condensing lens of quartz which focussed the rays on to the slit of a quartz spectrograph.

The A2Πi–X2Πi absorption spectrum of BrO

1981 ◽  
Vol 59 (12) ◽  
pp. 1908-1916 ◽  
Author(s):  
M. Barnett ◽  
E. A. Cohen ◽  
D. A. Ramsay
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Ground State ◽  
Flash Photolysis ◽  
Absorption Bands ◽  
Long Wavelength ◽  
Numbering Scheme ◽  
Ozonized Oxygen ◽  
Good Agreement

Absorption spectra of isotopically enriched 81Br16O and of normal BrO have been obtained by the flash photolysis of mixtures of bromine and ozonized oxygen. Rotational analyses are given for the 7–0, 12–0, 18–0, 19–0, 20–0, 21–0, 7–1, and 20–1 A2Π3/2–X2Π3/2 sub-bands of 81Br16O. The value for [Formula: see text] is found to be 722.1 ± 1.1 cm−1 in good agreement with the value calculated from microwave constants. Several additional bands have been found at the long wavelength end of the spectrum, necessitating a revision of the vibrational numbering scheme for both the emission and absorption bands. "Hot" bands up to ν″ = 6 have been observed in the absorption spectrum for the 2Π3/2 component of the ground state but no bands have yet been identified from the 2Π1/2 component.

Thiophosgene monomer–dimer equilibria in perfluoroalkane solutions: spectroscopic and photophysical implications of self-association in the ground state

1993 ◽  
Vol 71 (10) ◽  
pp. 1548-1555 ◽  
Author(s):  
Andrzej Maciejewski ◽  
Marian Szymanski ◽  
Ronald P. Steer
Keyword(s):  
Absorption Spectrum ◽  
Oscillator Strength ◽  
Absorption Spectra ◽  
Strong Evidence ◽  
Ground State ◽  
Excitation Spectra ◽  
Direct Excitation ◽  
Self Association ◽  
Single Formula ◽  
Self Aggregation

The S2–S0 absorption, emission, and emission excitation spectra of thiophosgene in a perfluoroalkane solvent have been measured as a function of the analytical concentration, C, of the solute. Strong evidence of the formation of van der Waals dimers at 10−4 M < C < 10−1 M and of higher oligomers at C > 10−1 M has been found. Variations in the absorption spectra at C < 10−1 M have been analyzed successfully in terms of a single [Formula: see text] equilibrium, for which the value of K is (5.0 ± 0.4) × 102 M−1 at 295 K. The mole fractions of monomer and dimer have been calculated at each C, and have been used to construct the absorption spectrum of the dimer. Both the monomer and dimer have similar S0 → S1, and S0 → S2 absorption spectra, but the dimer has an oscillator strength that is about twice that of the monomer. The effects of self-aggregation on the S2–S0 emission and excitation spectra have been analyzed. Absorption by the dimer in the ultraviolet also leads to emission, but with a different quantum efficency compared with direct excitation of the monomer. The implications of these observations on the interpretation of the spectroscopy, photophysics, and photochemistry of thiophosgene in solution are assessed.

The absorption spectrum of liquid bromine

1937 ◽  
Vol 162 (910) ◽  
pp. 414-419 ◽  
Author(s):  
D. Porret ◽  
Frederick George Donnan
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Ground State ◽  
Wave Length ◽  
Electronic States ◽  
Excited Electronic States ◽  
Long Wave ◽  
Liquid Bromine ◽  
Continuous Absorption ◽  
The Continuum

The continuous absorption spectra of gaseous bromine (Peskow 1917; Ribaud 1919; Gray and Style 1929; Acton, Aikin and Bayliss 1936) and of dissolved bromine (Bovis 1929; Gillam and Morton 1929) have been studied many times. They present a wide continuum (from about 30, 000 to 17, 000 cm. -1 .) with a maximum at 24, 000 cm. -1 . For the gas the continuum is preceded by two band systems on the long wave-length side. These systems converge at 19, 585 and 15, 896 cm. -1 . respectively. Acton, Aikin and Bayliss (1936) have shown that the continuum is not simple, and Mulliken (1936) and Darbyshire (1937) have pointed out that there are three overlapping continua corresponding to transitions from the ground state to three different excited electronic states. There are 3 II 0 + ← 1 Σ g , 3 II 1 ← 1 Σ g and 1 II ← 1 Σ g . The absorption spectrum of liquid bromine has been studied by Bovis (1929) form 18, 525 to 31, 750c cm. -1 . and by Camichel (1893) for two frequencies only (16, 978 and 18, 691 cm. -1 ).

THE ABSORPTION SPECTRUM OF BO2

1961 ◽  
Vol 39 (12) ◽  
pp. 1738-1768 ◽  
Author(s):  
J. W. C. Johns
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
Detailed Analysis ◽  
Ground State ◽  
Flash Photolysis ◽  
Electronic Transitions ◽  
Molecular Constants ◽  
Boron Trichloride ◽  
Symmetric Molecule ◽  
First Excited State

The boron flame bands have been observed in absorption during the flash photolysis of mixtures of boron trichloride and oxygen. Detailed analysis of the spectrum has shown that the bands arise from two electronic transitions in the linear symmetric molecule BO2, [Formula: see text] and A2Πu−X2Πg. The main molecular constants, in cm−1 except for r0, are summarized below:[Formula: see text]Both 2Π states show the Renner effect. In the ground state the Renner parameter, εω2, was found to be −92.2, whereas in the first excited state it is much smaller, −13.1 cm−1.

Excited State Polarizability of Some Polycyclic Polyenes

2017 ◽  
Vol 68 (2) ◽  
pp. 307-310 ◽  
Author(s):  
Ana Maria Ciubara ◽  
Andreea Celia Benchea ◽  
Carmen Beatrice Zelinschi ◽  
Dana Ortansa Dorohoi
Keyword(s):  
Excited State ◽  
Absorption Spectra ◽  
Excited States ◽  
Electronic Absorption ◽  
Ground State ◽  
Electronic Absorption Spectra ◽  
Photon Absorption ◽  
Absorption Process ◽  
Polar Solvents ◽  
Molecular Parameters

The electronic absorption spectra of five polycyclic polyenes were recorded in non-polar solvents in order to determine their polarizability in excited states from the strength of the dispersive interactions in their diluted solutions. The bathochromic shifts of p-p* vibronic bands prove the increase of the molecular polarizabilty in the photon absorption process. Some molecular parameters of the analyzed polyenes in their ground state were computed by using the programs from Spartan�14.

Absorption spectrum of the Mg2 molecule

1970 ◽  
Vol 48 (7) ◽  
pp. 901-914 ◽  
Author(s):  
W. J. Balfour ◽  
A. E. Douglas
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
High Resolution ◽  
Potential Energy ◽  
Dissociation Energy ◽  
Ground State ◽  
Potential Energy Curve ◽  
Energy Curve ◽  
Vibrational Constants

The absorption spectrum of the Mg2 molecule, which occurs in a furnace containing Mg vapor, has been photographed with a high resolution spectrograph. The rotational structures of the bands have been analyzed and the rotational and vibrational constants of the two states determined. The bands are found to arise from a 1Σ–1Σ transition between a very lightly bonded ground state and a more stable excited state. The R.K.R. potential energy curve of the ground state, which has a dissociation energy of 399 cm−1, has been determined. The more important constants of the ground state are ωe = 51.12 cm−1, ωexe = 1.64 cm−1, re = 3.890 Å and those of the upper state are ωe = 190.61 cm−1, ωexe = 1.14 cm−1, re = 3.082 Å.

scholarly journals The Near-ultraviolet Absorption Spectrum of Diimide Vapor

1974 ◽  
Vol 52 (6) ◽  
pp. 1006-1012 ◽  
Author(s):  
R. A. Back ◽  
C. Willis ◽  
D. A. Ramsay
Keyword(s):  
Absorption Spectrum ◽  
Bond Length ◽  
Gas Phase ◽  
Absorption Spectra ◽  
Ground State ◽  
Ultraviolet Absorption ◽  
Ultraviolet Absorption Spectrum ◽  
Near Ultraviolet ◽  
Bending Mode ◽  
Franck Condon

Absorption spectra of N2H2 and N2D2 in the gas phase have been obtained in the region 3000–4300 Å, consisting of about 30 diffuse bands for each compound. Long progressions in the spectra are attributed to excitation of the H—N=N bending mode, v2′, in the upper state, with much shorter progressions arising from the N=N stretching mode, v3′; values of v2′ = 1215 and 910 cm−1 and v3′ = 1550 and 1440 cm−1 were estimated for N2H2 and N2D2 respectively.The spectra are attributed to the 1Bg ← 1Ag(π* ← n+) transition of trans diimide, probably made allowed by vibronic interaction. From Franck–Condon calculations the H—N=N angle in the upper state was estimated to be 132 ± 2°, an increase of 25° from the ground-state value; the increase in the N=N bond length was estimated to be about 0.05 Å.

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