The Vacuum Ultraviolet Spectrum of ICI

1975 ◽  
Vol 53 (8) ◽  
pp. 812-824 ◽  
Author(s):  
Putcha Venkateswarlu
Keyword(s):  
Absorption Spectrum ◽  
Ionization Potential ◽  
Ground State ◽  
Vacuum Ultraviolet ◽  
Band System ◽  
Ultraviolet Spectrum ◽  
Similar Series ◽  
Iodine Chloride ◽  
Rydberg Transitions ◽  
Concave Grating

The absorption spectrum of iodine chloride has been photographed in the high orders of a 10.7 m concave grating spectrograph in the region 1900–1220 Å. A number of band systems which correspond to Rydberg transitions have been obtained. In addition an extensive band system with closely spaced bands degraded to longer wavelengths has been observed in the region 1660–1580 Å. Among the Rydberg systems, 12 series have been found to converge to 81 362 ± 80 cm−1 which very likely represents the ionization potential of the molecule leading to the 2Π3/2 state of the molecular ion. They are due to transitions from the ground state to states arising from the configurations (σ2π4π32Π3/2)ns σ, (2Π3/2)np σ, (2Π3/2)np π, (2Π3/2)nd σ, (2Π3/2)nd π, (2Π3/2)nd δ, (2Π3/2)nf σ, (2Π3/2)nf π, and (2Π3/2)nf δ where n takes the running values 6, 7, 8, … for the first three configurations, 5, 6, 7, … for the next three configurations, and 4, 5, 6, … for the last three configurations. The first few numbers of 11 similar series corresponding to the transitions to the states involving the (σ2π4π32Π1/2) core have been identified and the ionization of these series is estimated to be at 85 996 ± 80 cm−1.

The vacuum ultraviolet spectrum of the bromine molecule

1969 ◽  
Vol 47 (22) ◽  
pp. 2525-2538 ◽  
Author(s):  
Putcha Venkateswarlu
Keyword(s):  
Absorption Spectrum ◽  
Ionization Potential ◽  
Ground State ◽  
Vacuum Ultraviolet ◽  
Band System ◽  
Rydberg States ◽  
Ultraviolet Spectrum ◽  
Similar Series ◽  
Ionization Limit ◽  
Rydberg Transitions

The absorption spectrum of bromine has been photographed in the first and higher orders of a 10.7-m. concave vacuum grating spectrograph in the region 1700–1170 Å.A number of band systems have been obtained in the region 1510–1170 Å, most of which correspond to Rydberg transitions. In addition, an extensive band system with closely-spaced bands degraded to longer wavelengths has been recorded in the region 1700–1500 Å. Among the Rydberg systems, five series have been found to converge to 85 165 ± 80 cm−1 which represents the ionization potential of the molecule leading to the 2Π3/2g state of the molecular ion. They arise due to transitions from the ground state to [σg2πu4πg32Π3/2g]npσu, [σg2πu4πg32Π3/2g]npπu, [σg2πu4πg32Π3/2g]nfσu, [σg2πu4πg32Π3/2g]nfπu, and [σg2πu4πg32Π3/2g]nfδu configurations where n takes the running values 5, 6, 7, … etc. The first few members of four similar series corresponding to the transitions to the states involving the [σg2πu4πg32Π1/2g] core have been identified and the ionization limit of these series is estimated to be at 88 306 ± 80 cm−1. Two of the remaining band systems have been found to be very likely due to transitions to the Rydberg states with the configurations [σg2πu3πg42Π3/2u]5sσg and [σg2πu3πg42Π1/2u]5sσg, respectively. Three of the observed systems which do not involve Rydberg states appear to have for their upper levels the 1Πu(1u), 3Π(1u), and 3Π(0u+) states arising from the configuration σgπu3πg4σu2.

The 1650-1350 Å absorption spectrum of nitrogen dioxide

1962 ◽  
Vol 267 (1330) ◽  
pp. 395-407 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Nitrogen Dioxide ◽  
Ionization Potential ◽  
Ground State ◽  
Band System ◽  
Anharmonic Constant ◽  
Rydberg Transitions ◽  
First Ionization Potential

An analysis of the 1650-1350 Å band system of nitrogen dioxide has been carried out. A pattern of band spacings and intensities is found that is complex but regular. It is shown that this pattern is qualitatively, and to a large extent quantitatively, just what would be expected for a transition in which the shape of the molecule changes from bent to linear. The transition is a parallel one and the upper state has 2 Σ + u symmetry. The symmetrical stretching frequency is increased from its ground-state value to ca. 1420 cm -1 in the upper state. The upper-state bending frequency is ca. 600 cm -1 . The N — O length is decreased from its groundstate value, probably to 1·1(3) Å. The upper state resembles closely the ground state of NO + 2 . The transition is to be classed as one of the Rydberg transitions leading to the first ionization potential of NO 2 ; and the orbital to which the odd electron is transferred in the transition is (pσ) in type. The anharmonic constant g 22 for the linear upper state is found to be 2·(3) cm -1 . Other Rydberg transitions may well be present in the region, but have not been definitely identified.

Vacuum ultraviolet spectrum of the iodine molecule

1970 ◽  
Vol 48 (9) ◽  
pp. 1055-1079 ◽  
Author(s):  
Putcha Venkateswarlu
Keyword(s):  
Vacuum Ultraviolet ◽  
Rydberg States ◽  
Rydberg Series ◽  
Molecular Ion ◽  
Similar Series ◽  
Common Limit ◽  
The Common ◽  
Ionization Limit ◽  
Rydberg Transitions ◽  
Concave Grating

The absorption spectrum of iodine has been photographed in the higher orders of a 10.7 m concave grating spectrograph in the region 1950–1200 Å. A number of band systems has been obtained, most of which correspond to Rydberg transitions. The limit of the Rydberg series leading to the 2Π3/2g state of the molecular ion has been recorded and the corresponding ionization potential is found to be 75 814 ± 10 cm−1. Five series have been found which terminate at this common limit. They represent transitions from the ground state to [σg2πu4Πg32Π3/2g]np σu Π1u, [σg2πu4πg32Π3/2g]np πu Σ+ (0u+), [σg2πu4πg32Π3/2g]nf σu Π1u, [σg2πu4πg32Π3/2g]nf πu, Σ+(0u+), and [σg2πu4πg32Π3/2g]nf δu Π1u states respectively, where n takes the running values 6, 7, 8, … etc. for the first three series and 4, 5, 6, … etc. for the last two series. The series limit of the bands corresponding to the molecules with ν″ = 1 has been found to be at 75 600 ± 10 cm−1. The first few members of similar series corresponding to transitions to different states involving the common [σg2πu4πg32Π1/2g] core have been identified and the ionization limit of these series is estimated to be at 80 895 ± 50 cm−1. Some of the remaining band systems obtained have been found to be very likely due to transitions to the Rydberg states involving molecular ion cores like [σg2πu 3πg42Π3/2u], [σg2πu3πg42Π1/2u], and [σg2πu4πg2σu2Σu+]. Three of the observed band systems do not appear to involve Rydberg states and their upper levels are very likely the 1Π(1u), 3Π(1u), and 3Π(0u+) states arising from the configuration σgπu3πg4σu2. The positions of these levels are at 64 956, 62 844, and 61 847 cm−1, the corresponding vibrational frequencies being 145, 144, and 109 cm−1 respectively.

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.

A Discussion on astronomy in the ultraviolet - A study of interstellar lines in the rocket spectrum of δ Scorpii

1975 ◽  
Vol 279 (1289) ◽  
pp. 317-322
Keyword(s):  
Ground State ◽  
Atomic Hydrogen ◽  
Vacuum Ultraviolet ◽  
Velocity Dispersion ◽  
Ultraviolet Spectrum ◽  
Ultraviolet A ◽  
Average Ratio ◽  
Solar Abundances ◽  
Fe Ions ◽  
Cloud Density

An analysis is made of ten interstellar lines in the vacuum ultraviolet spectrum of 8 Sco. The data were taken from a rocket spectrogram with wavelength coverage extending from 1177 to 1717 A with a resolution of approximately 0.15 A. Column densities of C°, C+, N°, 0°, A1+, Si+ and Fe+ are derived, from which abundances relative to atomic hydrogen are determined. Compared to corresponding solar abundances, silicon and iron are slightly overabundant whereas the remaining species are underabundant by factors of 1.8 to 8.6. It is shown that the relative Fe abundance may be made significantly less than the solar value by arbitrarily increasing the velocity dispersion of the Fe+ ions by a factor of 2. The relative populations of the carbon atoms ground state fine structure levels combined with two possible mean cloud temperatures of 47 and 76 K determined from the interstellar H 2 spectrum yield a mean cloud density of 250 and 150 cm-3 respectively. Using the appropriate column densities of neutral and singly ionized carbon atoms, the average ratio of the electron density at the hydrogen atom density for each temperature is found to be 2.1 x 10-4 and 4.8 x 10~2 *4 respectively.

The absorption spectrum of Cl2 in the vacuum ultraviolet

1981 ◽  
Vol 59 (6) ◽  
pp. 835-840 ◽  
Author(s):  
A. E. Douglas
Keyword(s):  
Absorption Spectrum ◽  
Vacuum Ultraviolet ◽  
Band System ◽  
Rydberg States ◽  
Ultraviolet Region ◽  
Isotopic Molecule ◽  
Vacuum Ultraviolet Region ◽  
Vibrational Constants ◽  
Made In

The absorption spectrum of Cl2 in the vacuum ultraviolet region has been photographed with sufficient resolution to allow rotational analyses of many bands. The separated isotopic molecule 35Cl2 and cooled absorption cells were used to simplify the spectrum. A band system associated with an ionic state has been observed in the 1330–1450 Å range. Many large perturbations in the system prevent the determination of the usual rotational and vibrational constants. Some progress has been made in the analyses of a few bands associated with Rydberg states.

The electronic spectrum of F2

1976 ◽  
Vol 54 (13) ◽  
pp. 1343-1359 ◽  
Author(s):  
E. A. Colbourn ◽  
M. Dagenais ◽  
A. E. Douglas ◽  
J. W. Raymonda
Keyword(s):  
Absorption Spectrum ◽  
Ground State ◽  
Band System ◽  
Rydberg States ◽  
Rotational Analysis ◽  
Interaction Energies ◽  
Rydberg Series ◽  
Rotational Constants ◽  
Vibrational Levels ◽  
Ionic States

The absorption spectrum of F2 in the 780–1020 Å range has been photographed at sufficient resolution to allow a rotational analysis of many bands. A large number of vibrational levels of three ionic states have been observed and their rotational constants determined. Many perturbations in the rotational structure caused by the interaction between the three states have been investigated and the interaction energies determined. The rotational and vibrational structures of a few Rydberg states have also been analyzed in detail but no Rydberg series have been identified. The difficulties in assigning the observed states are discussed. A 1Σu+ – X1Σg+ emission band system has been observed in the 1100 Å region. An analysis of the bands of this system has allowed us to determine the term values and rotational constants of all the vibrational levels of the ground state with ν ≤ 22. The dissociation energy, D0(F2), is found to be greater than 12 830 and is estimated to be 12 920 ± 50 cm−1.

ON THE ABSORPTION SPECTRUM OF H2O AND D2O IN THE VACUUM ULTRAVIOLET

1963 ◽  
Vol 41 (2) ◽  
pp. 209-219 ◽  
Author(s):  
J. W. C. Johns
Keyword(s):  
Absorption Spectrum ◽  
Water Vapor ◽  
High Resolution ◽  
Heavy Water ◽  
Vacuum Ultraviolet ◽  
Rydberg Series ◽  
Accuracy Of Measurement ◽  
Concave Grating

The spectra of normal and heavy water vapor have been observed under high resolution in the region 1220–1240 Å. One band of H2O and two bands of D2O have been measured and analyzed. The spectra were taken in the ninth order of a 35-ft concave-grating spectrograph and the accuracy of measurement of the sharper lines is estimated to be about ± 0.005 Å. The results of the analyses are summarized below.[Formula: see text]These bands have been assigned as belonging to the first member of one of the two np Rydberg series.

Rydberg series and autoionization resonances in the Y I absorption spectrum

1973 ◽  
Vol 333 (1592) ◽  
pp. 17-24 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Ionization Potential ◽  
Excited States ◽  
Spectral Range ◽  
Ground State ◽  
Rydberg Series ◽  
A Value ◽  
Doublet Ground State ◽  
Ionization Limit ◽  
First Ionization Potential

The absorption spectrum of yttrium vapour has been photographed in the spectral range 1650 to 2250 À, with a 10 m spectrograph. Series of autoionization resonances, which converge on excited states of the Y + ion have been identified, as combinations with the doublet ground-state of Y I , 5s 2 4d 2 D 3/2 , 5/2 . Although the lines of these series show broadened and often asymmetrical profiles, the lines are sufficiently well defined to fix a value for the first ionization potential of Y I , which differs from the previously accepted value by approximately 2500 cm -1 . In addition, approximately 400 new Y I lines, which involve excited levels below the first ionization limit of Y I , namely 4s 2 1 S o , have been found. The majority of these are unclassifiable at present but, the value for the first ionization-potential being known from the resonances above-mentioned, two series of the character 5s 2 4d 2 D 3/2 , 5/2 -5s 2 nf 2 F o have been identified. In addition to the identifications of series, 152 new lines below the 5s 2 1 S o limit identify 76 new levels of Y I , of odd parity.

The absorption spectrum of trans-diimide (N2H2) in the vacuum ultraviolet region

1981 ◽  
Vol 59 (3) ◽  
pp. 506-517 ◽  
Author(s):  
P. S. Neudorfl ◽  
R. A. Back ◽  
A. E. Douglas
Keyword(s):  
Absorption Spectrum ◽  
Gas Phase ◽  
Vacuum Ultraviolet ◽  
Singlet State ◽  
Ultraviolet Region ◽  
Ultraviolet Absorption Spectrum ◽  
Rotational Analysis ◽  
Trans Conformation ◽  
Vacuum Ultraviolet Region ◽  
Rydberg Transitions

The vacuum ultraviolet absorption spectrum of trans-diimide (N2H2) in the gas phase has been re-examined between 1800 and 1300 Å, using diimide prepared by the thermal decomposition of sodium tosylhydrazide. Two band systems were observed, designated [Formula: see text] and [Formula: see text], with origins at 1727 and 1473 Å, which have been assigned to the Rydberg transitions 3pπ(bu) ← n+ and 4pπ(bu) ← n+ respectively. Both systems show long progressions in v2′, the N—N—H symmetric bending frequency, and short progressions in v3′, the symmetric N—N stretching frequency.The [Formula: see text] system has well-resolved rotational J type structure in some bands, and the rotational analysis showed that the ground state is a totally symmetric singlet state of C2h symmetry (planar trans-N2H2 isomer), and that the system arises from a 1Bu ← 1Ag transition. Rotational constants obtained for the 0–0 band of the [Formula: see text]-state were A = 15.63, B = 1.32, and C = 1.22 cm−1, and the values of rH−N = 1.028 Å, rH−N = 1.167 Å, and [Formula: see text] were estimated from them assuming a planar trans conformation.

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