Absorption Spectrum of H2 in the Vacuum‐uv Region. II. Rydberg Series Converging to the First Six Vibrational Levels of the H2+ Ground State

1970 ◽  
Vol 52 (11) ◽  
pp. 5793-5799 ◽  
Author(s):  
Sanzo Takezawa
Keyword(s):  
Absorption Spectrum ◽  
Ground State ◽  
Rydberg Series ◽  
Vibrational Levels ◽  
Region Ii ◽  
Vacuum Uv

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.

scholarly journals Photochemical reactions in the fluorite region II─Photochemical decomposition of formaldehyde vapour

1937 ◽  
Vol 163 (913) ◽  
pp. 221-227 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Absorption Spectrum ◽  
Ground State ◽  
Wave Length ◽  
Ultra Violet ◽  
Photochemical Reactions ◽  
Photochemical Decomposition ◽  
The Subject ◽  
Region Ii ◽  
Formaldehyde Vapour

The photochemical decomposition of formaldehyde in the near ultra­-violet has been the subject of several investigations. It is known (Norrish and Kirkbride 1932) that the products are chiefly carbon monoxide and hydrogen, and that neither the composition of the products nor the quantum yield depends appreciably on wave-length. Recently Price (1935) has investigated the far ultra-violet absorption spectrum of formaldehyde. The first band observed in this region occurs at about 1745 A and is very diffuse, whereas the first bands in acetaldehyde (Price 1935) and acetone (Noyes, Duncan and Manning 1934) occur at longer wave-lengths and are relatively much sharper. Price ascribes this diffuseness to a predissociation resulting from the interaction of the upper state in formaldehyde with the ground state and assumes that the primary dissociation at about 1745 A should be CH 2 O → hv 1745 A CH 2 + O.

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.

High resolution absorption spectrum of nitric oxide (NO) in the region of the first ionization limit

1976 ◽  
Vol 54 (20) ◽  
pp. 2074-2092 ◽  
Author(s):  
E. Miescher
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Ionization Energy ◽  
Dissociation Limit ◽  
Matrix Elements ◽  
Rydberg Series ◽  
Isotopic Species ◽  
Vibrational Levels ◽  
Energy Formula ◽  
Ionization Limit

The absorption spectrum of cold NO gas has been photographed at high resolution between 1400 and 1250 Å for two isotopic species. Resolved bands of the Rydberg series converging to vibrational levels of the 1Σ+ ground state of NO+ are studied. They include nf–X bands up to n = 15 and ns–X bands up to n = 11, all of which show sharp rotational structure. The higher members of the np–X series are generally very diffuse with only npσ being sufficiently sharp to show broadened rotational lines. Also mostly diffuse are the ndδ–X bands. The bands ndσ, π–X are not observed. The rapidly (n−3) narrowing structure of the nf complexes is discussed and the ionization energy [Formula: see text] accurately determined by extrapolation of selected rotational lines. Interactions between Rydberg states are numerous, s ~ d mixing produces a strong effect above n = 6 when (n + 1)s levels fuse with nl levels into 'supercomplexes'. Matrix elements are given for observed 8f ~ 9s and 6f ~ 6dδ interactions.Valence levels are not observed above the ionization energy, except for the repulsive state A′2Σ+ arising from the first dissociation limit and seemingly assuming Rydberg character at molecular internuclear distance. Observed anomalies are qualitatively discussed.

The absorption spectrum of NH2 between 6250 and 9500 Å

1976 ◽  
Vol 54 (17) ◽  
pp. 1804-1814 ◽  
Author(s):  
J. W. C. Johns ◽  
D. A. Ramsay ◽  
S. C. Ross
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
Ground State ◽  
Absorption System ◽  
Molecular Constants ◽  
Bending Vibration ◽  
Long Wavelength ◽  
Vibrational Levels

The earlier analysis by Dressier and Ramsay of the [Formula: see text] absorption system of NH2 has been considerably extended at the long wavelength end of the spectrum. All the low-lying vibronic levels of the excited state have been identified up to ν2′ = 8. These levels are 010(K = 0), 020(K = 1), 030(K = 0,2), 040(K = 1,3), 050(K = 0,2,4), 060(K = 1,3,5), 070(K = 0,2,4,6), and 080(K = 1,3,5,7). Large perturbations (~ 200 cm−1) have been observed between some of these levels and high vibrational levels of the ground state. Accurate molecular constants have been obtained for the ground state and for the first level involving the bending vibration (ν2″ = 1).

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).

High resolution absorption studies of the b1Πu ← X1Σg+ system of nitrogen

1969 ◽  
Vol 47 (5) ◽  
pp. 563-589 ◽  
Author(s):  
P. K. Carroll ◽  
C. P. Collins
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Triplet State ◽  
Rotational Structure ◽  
Dissociation Limit ◽  
Rydberg Series ◽  
Absorption Studies ◽  
Vibrational Levels ◽  
Single Transition ◽  
Made In

New high resolution studies of the absorption spectrum of N2 have been made in the region 1015–795 Å. Analyses are given of 25 non-Rydberg bands of the type 1Πu–X1Σg+. It is shown that all of these bands, which include the i, j, b, l, m, p, and q groups of Worley, together with several new bands not previously observed, can be assigned to a single transition the upper state of which is called b1Πu. The pronounced irregularities in the vibrational and rotational structure of the b state are attributed to a homogeneous interaction with the first member (n = 3) of the ---(3σg) npπu, 1Πu Rydberg series. This perturbation is discussed in the accompanying paper by Dressier who recognized its importance in the interpretation of the spectrum. Diffuseness in the rotational lines of several bands at lower ν was observed and is attributed to predissociation by a triplet state, probably the C′ 3Πu state which goes to the 4S + 2D dissociation limit. Three levels of the b state show measurable Λ-type doubling which can be interpreted as caused by interaction with vibrational levels of the first member (n = 4) of the --(3σg) npσu, 1Σu+ Rydberg series. The assignment of 28 non-Rydberg 1Σu+ levels, including the b′, g, f, r, s, and t "states", to a single 1Σu+ state which is called b′, is also briefly discussed.

Rydberg series and autoionization resonances in the Sc I absorption spectrum

1973 ◽  
Vol 333 (1592) ◽  
pp. 1-16 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Ionization Potential ◽  
Excited States ◽  
Spectral Range ◽  
Ground State ◽  
Rydberg Series ◽  
Doublet Ground State

The absorption spectrum of scandium vapour has been photographed in the spectral range 1200 to 3200 A, with 3 and 10 m spectrographs. Six long Rydberg series and two shorter ones have been identified, as combinations with the doublet ground -state of Sc I, 4s 2 3d 2 D3/ 2 , 5/2 . The series all converge on excited states of Sc n and nearly all their members lie in the continua beyond the 3d4s 3 D ground-levels of the ion, consequently showing a variety of autoionization profiles. The series yield a reliable value for the ionization potential of Sc I, which differs by only 2 cm -1 from an earlier estimate. The addition to the series, approximately 800 new lines of Sc I have been found. The majority of these are unclassifiable at present, and are not reported, but 236 of the lines, which locate 118 new odd levels of Sc I, are listed. Also, some major autoionization-broadened features, though not definitely classifiable, are described.

Rotational Structure in the Absorption Spectrum of SO2 between 3000 Å and 3300 Å

1975 ◽  
Vol 53 (23) ◽  
pp. 2555-2576 ◽  
Author(s):  
Y. Hamada ◽  
A. J. Merer
Keyword(s):  
Absorption Spectrum ◽  
Electronic State ◽  
Intensity Distribution ◽  
Ground State ◽  
Electronic Transition ◽  
Wavelength Region ◽  
Vibronic Coupling ◽  
Banded Structure ◽  
Vibrational Levels ◽  
Type C

Rotational analyses have been carried out, with varying degrees of completeness, for nine bands of S16O2 and two bands of S18O2 in the region 3000–3300 Å. The bands are all highly perturbed type C bands, which go to b2 vibrational levels of the ππ* Ã1A2 electronic state. The [Formula: see text] electronic transition shows an anomalous vibrational intensity distribution, which indicates that the Ã1A2 state undergoes strong Born–Oppenheimer (nuclear momentum) vibronic coupling with the [Formula: see text] electronic state. All the obvious banded structure in this wavelength region can be assigned to the [Formula: see text] transition. Although no analyses of bands belonging to the [Formula: see text] transition have been carried out (since the [Formula: see text] state is so massively perturbed by the ground state), reasons are presented for placing its (0,0) band between 3100 and 3160 Å.

THE ABSORPTION SPECTRUM OF SH AND SD IN THE VACUUM ULTRAVIOLET

1966 ◽  
Vol 44 (10) ◽  
pp. 2447-2459 ◽  
Author(s):  
B. A. Morrow
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
Excited States ◽  
Ground State ◽  
Vacuum Ultraviolet ◽  
Flash Photolysis ◽  
Electronic States ◽  
Rydberg Series ◽  
A Value ◽  
Vibrational Constants

The absorption spectrum of SH in the vacuum ultraviolet has been obtained by the flash photolysis of hydrogen sulfide. Transitions from the 2Π ground state to seven excited states have been observed and four of these fit reasonably well into a Rydberg series. From an extrapolation to the convergence limit of this series, a value of 10.40 ± 0.03 eV for the ionization potential of SH has been derived. Values for the rotational constants of these new electronic states have been determined; corresponding data for SD have also been obtained. The (1–0) transition of the system near 1 670 Å (B2Σ–X2Π) was observed, and, with the aid of isotope relations, vibrational constants of the B state have been derived. An estimate of the dissociation energy of SH in this excited state is D0′ = 24 190 ± 1 000 cm−1.

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