THE 2 700 Å BANDS OF THE N3 MOLECULE

1965 ◽  
Vol 43 (12) ◽  
pp. 2216-2221 ◽  
Author(s):  
A. E. Douglas ◽  
W. Jeremy Jones
Keyword(s):  
Fine Structure ◽  
High Resolution ◽  
Ground State ◽  
Flash Photolysis ◽  
Bond Distance ◽  
Absorption Bands

The 2 700 Å absorption bands found by Thrush in the flash photolysis of HN3 have been studied at high resolution. The rotational fine structure of the strongest band has been analyzed, and it has been shown that the bands arise from a [Formula: see text] transition of the N3 molecule. The bond distance in the ground state of N3 is found to be 1.181 Å.

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.

ABSORPTION SPECTRA OF C3 AND C3H2 FROM THE FLASH PHOTOLYSIS OF DIAZOPROPYNE

1967 ◽  
Vol 45 (12) ◽  
pp. 4103-4111 ◽  
Author(s):  
A. J. Merer
Keyword(s):  
Absorption Spectrum ◽  
Free Radical ◽  
Ground State ◽  
Time Delays ◽  
Flash Photolysis ◽  
State Level ◽  
Vibrational Structure ◽  
Absorption Bands ◽  
Text Component ◽  
Ground State Level

The flash photolysis of diazopropyne (HC2∙CHN2) provides a particularly strong absorption spectrum of the free C3 radical. About 40 μs after the photolysis flash, the appearance of the [Formula: see text] (4 050 Å) system of C3 is similar to that obtained in the flash photolysis of diazomethane by Gausset, Herzberg, Lagerqvist, and Rosen, though much more intense. The intensity of the spectrum has permitted a study of the l-type doubling effect in the ground-state level 6ν2, of which the [Formula: see text] component has been found to lie at 458.2 cm−1. At shorter time delays [Formula: see text] the spectrum is complicated by bands arising from the levels ν1″ (1 224.5 cm−1) and 2ν1″ (2 436.0 cm−1).Below 3 700 Å the C3 spectrum is overlapped by absorption bands belonging to a new free radical, which has been identified from the intensity alternation in the rotational structure as the HCCCH radical. The vibrational structure of this system is exceptionally complex, and analysis has not been possible. The bands extend to about 3 100 Å, but are predissociated below 3 450 Å.

SPECTRUM AND STRUCTURE OF THE FREE HNCN RADICAL

1963 ◽  
Vol 41 (2) ◽  
pp. 286-298 ◽  
Author(s):  
G. Herzberg ◽  
P. A. Warsop
Keyword(s):  
Fine Structure ◽  
Ground State ◽  
Electronic Transition ◽  
Flash Photolysis ◽  
Geometrical Structure ◽  
Transition Moment ◽  
Lower State ◽  
State Formula ◽  
Exact Position

A widely spaced perpendicular band at 3440 Å observed in the flash photolysis of diazomethane is ascribed to the free HNCN radical. The study of the fine structure of this band for HNCN, DNCN, and HNC13N has yielded information about the geometrical structure of the molecule in both the upper and lower (ground) state. For the lower state[Formula: see text]The N—C—N group is very nearly linear, but the exact position of the C atom on this line could not be determined. The electronic transition is of the type 2A′–2A″, the transition moment being perpendicular to the plane of the molecule.

The ultraviolet absorption spectrum of the F 2 CN radical

1967 ◽  
Vol 300 (1462) ◽  
pp. 405-414 ◽  
Keyword(s):  
Molecular Structure ◽  
Absorption Spectrum ◽  
Ground State ◽  
Flash Photolysis ◽  
Ultraviolet Absorption ◽  
Ultraviolet Absorption Spectrum ◽  
Rotational Analysis ◽  
Absorption Bands ◽  
New System

A new system of absorption bands near 3600 Å has been observed during the flash photolysis of CF 3 NCF 2 and is ascribed to the free F 2 CN radical. The rotational analysis of the 0–0 band leads to the ground state molecular structure r CF = 1.310 Å (assumed), r CN = 1.265 ± 0.02 Å, FCF angle = 113.5 + 1°. The bands are shown to be type A bands arising from the transition 2 A 1 ← 2 B 2 , and the spectrum is compared with those of the iso-electronic molecules NO 3 and F 2 BO.

SPECTRA AND STRUCTURES OF THE FREE HSiCl AND HSiBr RADICALS

1964 ◽  
Vol 42 (3) ◽  
pp. 395-432 ◽  
Author(s):  
G. Herzberg ◽  
R. D. Verma
Keyword(s):  
Fine Structure ◽  
Band Structure ◽  
Excited States ◽  
Ground State ◽  
Electronic Transition ◽  
Flash Photolysis ◽  
Geometrical Structure ◽  
Lower State ◽  
Triplet Splitting ◽  
Singlet Transition

Intense spectra of HSiCl and HSiBr in the region 6000 to 4100 Å have been obtained in the flash photolysis of SiH3Cl and SiH3Br, both in absorption and in fluorescence. They consist of progressions of bands with very wide K structures and very narrow J structures. A detailed fine structure analysis of these bands has been carried out and the geometrical structure of the molecules in both the upper and the lower states has been established. For the lower state, probably the ground state of HSiCl, it is found that[Formula: see text]and similarly for HSiBr[Formula: see text]In the excited states the angles are appreciably larger (see Table XI).A striking feature of the band structure in both HSiCl and HSiBr is the occurrence of branches of subbands with ΔK = ± 2, in addition to those with ΔK = ± 1 and 0, and furthermore, the presence of a subband with K = 0 in the branch with ΔK = 0. These anomalies can be accounted for by the assumption that the electronic transition is a triplet–singlet transition, more specifically 3A″–1A′ (or possibly 1A′–3A″). However, no triplet splitting has been resolved in the spectrum.

Rotational analysis of the 13 200 and 13 400 cm−1 bands of NO2 by means of Fourier transform spectroscopy

1982 ◽  
Vol 60 (9) ◽  
pp. 1288-1302 ◽  
Author(s):  
A. Perrin ◽  
J. -M. Flaud ◽  
C. Camy-Peyret ◽  
P. Luc
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Ground State ◽  
Electronic Transition ◽  
Spin Orbit ◽  
Rotational Analysis ◽  
Coriolis Coupling ◽  
Absorption Bands ◽  
Vibrational Assignments ◽  
Fourier Transform Spectra

The analysis of two parallel absorption bands of NO2, at 13 400 and 13 200 cm−1 respectively, has been performed using high resolution Fourier transform spectra. This paper is an extension of the work performed on the 7390 Å band (13 500 cm−1) in 1977 by Hallin and Merer, and completed in 1980 by Perrin, Camy-Peyret, Flaud, and Luc.The lines involving the Ka = 0, 1, 2, 3, 4 stacks for the 13 400 cm−1 band and Ka = 0, 1, 3, 4 for the 13 200 cm−1 band have been assigned and considerable spin–orbit and/or Coriolis coupling induced transitions have been detected.The 13 400 cm−1 band can be considered as belonging to the [Formula: see text] electronic transition, while the 13 200 cm−1 band might be, as the 7390 Å band (at 13 500 cm−1), a transition within the ground state manifold which barrows its intensity through vibronic coupling from the 13 400 cm−1 band. Tentative vibrational assignments are given.

Investigation of Fine Structure in the Photoneutron Cross Sections of 16O and 208Pb

1975 ◽  
Vol 53 (15) ◽  
pp. 1434-1442 ◽  
Author(s):  
R. G. Johnson ◽  
J. D. Irish ◽  
K. G. McNeill
Keyword(s):  
Fine Structure ◽  
High Resolution ◽  
Differential Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
Center Of Mass ◽  
Energy Spectra ◽  
Neutron Time ◽  
Good Agreement

The structure in the photoneutron cross sections of 16O and 208Pb has been studied by the measurement of high resolution photoneutron energy spectra using the neutron time-of-flight technique and bremsstrahlung irradiations. For 16O, the ground state differential cross section at 98° has been deduced between 17.3 and 28.5 MeV and is in good agreement with most previous studies. Fine structure is seen throughout the cross section. Eight neutron energy spectra for 208Pb from bremsstrahlung endpoint energies in the range 11.0 to 15.5 MeV were obtained. Strong peaks are seen at center of mass neutron energies of 1.67, 1.85, 2.06, 2.19, 2.68, 3.15, 3.27, 3.50, 3.77, and 4.03 MeV with weaker peaks elsewhere. The energies of these peaks are in good agreement with previous measurements in this laboratory. The energies of peaks in the spectra are compared with recent cross section measurements.

THE 1Πu ← 1Δg ELECTRONIC SPECTRUM OF NCN

1967 ◽  
Vol 45 (4) ◽  
pp. 1439-1450 ◽  
Author(s):  
H. W. Kroto
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption Spectrum ◽  
Electronic Spectrum ◽  
Electronic Absorption ◽  
Ground State ◽  
Flash Photolysis ◽  
Bond Distance ◽  
Splitting Parameter

The analysis of a new electronic absorption spectrum observed during the flash photolysis of cyanogen azide, NCN3, in the region 3 327 Å indicates that the spectrum belongs to a 1Πu–1Δg transition of NCN. The 1Δg state is metastable with respect to the [Formula: see text] ground state. The bond distance in the 1Δg state is 1.228 5 Å. The value of the Renner splitting parameter, εω2, for the 1Πu state has been determined as −84.2 cm−1.

THE ABSORPTION SPECTRUM OF 35Cl2 FROM 4780 TO 6000 Å

1963 ◽  
Vol 41 (7) ◽  
pp. 1174-1192 ◽  
Author(s):  
A. E. Douglas ◽  
Chr. Kn. Møller ◽  
B. P. Stoicheff
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Ground State ◽  
Dissociation Limit ◽  
Complex Spectrum ◽  
Absorption Bands ◽  
Isotopic Species ◽  
Concave Grating

The discrete absorption bands of gaseous chlorine which lie between 6000 Å and the dissociation limit, near 4780 Å, have been photographed at high resolution with a 10-meter concave-grating spectrograph. This complex spectrum has been simplified by the use of the separated isotopic species 35Cl2 and by cooling the cell. An analysis of all the strong bands has been achieved. The principal constants of the ground state are Be = 0.24407, α = 0.00153, ωe = 559.71, ωexe = 2.70, [Formula: see text], and re = 1.9878 Å.

High-resolution scanning electron microscopy of thin-film magnetic media of magnetic recording disk

1992 ◽  
Vol 50 (2) ◽  
pp. 1334-1335
Author(s):  
K. Ogura ◽  
H. Nishioka ◽  
N. Ikeo ◽  
T. Kanazawa ◽  
J. Teshima
Keyword(s):  
Thin Film ◽  
Fine Structure ◽  
High Resolution ◽  
Magnetic Recording ◽  
High Performance ◽  
Magnetic Hysteresis ◽  
Grain Structure ◽  
Magnetic Media ◽  
Cross Sectional ◽  
Resolution Observation

Structural appraisal of thin film magnetic media is very important because their magnetic characters such as magnetic hysteresis and recording behaviors are drastically altered by the grain structure of the film. However, in general, the surface of thin film magnetic media of magnetic recording disk which is process completed is protected by several-nm thick sputtered carbon. Therefore, high-resolution observation of a cross-sectional plane of a disk is strongly required to see the fine structure of the thin film magnetic media. Additionally, observation of the top protection film is also very important in this field.Recently, several different process-completed magnetic disks were examined with a UHR-SEM, the JEOL JSM 890, which consisted of a field emission gun and a high-performance immerse lens. The disks were cut into approximately 10-mm squares, the bottom of these pieces were carved into more than half of the total thickness of the disks, and they were bent. There were many cracks on the bent disks. When these disks were observed with the UHR-SEM, it was very difficult to observe the fine structure of thin film magnetic media which appeared on the cracks, because of a very heavy contamination on the observing area.

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