THE SPECTRUM OF SiH AND SiD

1965 ◽  
Vol 43 (12) ◽  
pp. 2136-2141 ◽  
Author(s):  
R. D. Verma
Keyword(s):  
Dissociation Energy ◽  
Rotational Analysis ◽  
Rotational Constants ◽  
Upper Limit ◽  
New States

Two new systems of SiH and SiD in the regions around 3 250 Å and 2 050 Å in addition to the well-known 2Δ−2Π system have been recorded in absorption and their rotational analysis (except for the 2Δ−2Π system of SiH) has been carried out. The new states are 2Σ+ at T0 = 30 974.69 cm−1 and 2Δ at T0 = 48 603.46 cm−1. The rotational constants for all the states known in SiD have been determined. The upper limit of the dissociation energy of SiH has been fixed at 24 680 cm−1 by predissociation.

scholarly journals Spectrum of the hydroxyl radical

1969 ◽  
Vol 47 (18) ◽  
pp. 1945-1957 ◽  
Author(s):  
C. Carlone ◽  
F. W. Dalby
Keyword(s):  
High Resolution ◽  
Hydroxyl Radical ◽  
Dissociation Energy ◽  
Spin Splitting ◽  
Oh Radical ◽  
Rotational Constants ◽  
Upper Limit ◽  
Vibrational Levels ◽  
State Formula ◽  
Potential Maximum

The B2Σ+ → A2Σ+ and C2Σ+ → A2Σ+ systems of OH and OD were photographed at high resolution. The apparent dissociation energy D0(A2Σ+) is calculated to be (18 847 ± 15) cm−1 for OH and (19 263 ± 15) cm−1 for OD. An upper limit to D0(X2Π3/2) of OH is deduced to be (35 420 ± 15) cm−1. Evidence for a potential maximum in the B2Σ+ state, which is about 100 cm−1 larger than that in the A2Σ+ state, is presented.The broadening of the rotational lines in several bands of both systems has established a strong predissociation of the A2Σ+ state near ν = 5 in OH. The lifetime of these predissociated levels is ≈10−11 s. A definite identification of the predissociating state has not been possible.Newly-discovered vibrational levels in the C2Σ+ state have led to the following constants, in cm−1, of the OH radical in the C2Σ+ state:[Formula: see text]Rotational constants and spin splitting constants in the A2Σ+ and B2Σ+ states, more accurate than previously available, are presented.

ROTATIONAL ANALYSIS OF THE β BANDS OF PHOSPHORUS MONOXIDE

1959 ◽  
Vol 37 (2) ◽  
pp. 136-143 ◽  
Author(s):  
Nand Lal Singh
Keyword(s):  
Ground State ◽  
Band System ◽  
Electronic States ◽  
Rotational Analysis ◽  
Rotational Constants ◽  
Fine Structures ◽  
Π State

The fine structures of three of the β bands of PO which occur near 3200 Å have been analyzed. The analysis shows that the upper state of this band system is a 2Σ and not a 2Π state as previously believed. The rotational constants of both electronic states have been determined and it is found that the ground state constants, previously determined from the γ bands, are incorrect.

THE EMISSION SPECTRUM OF THE PbBr MOLECULE

1967 ◽  
Vol 45 (11) ◽  
pp. 3663-3666 ◽  
Author(s):  
K. M. Lal ◽  
B. N. Khanna
Keyword(s):  
Emission Spectrum ◽  
Visible Region ◽  
Second Order ◽  
Rotational Analysis ◽  
Rotational Constants ◽  
Concave Grating

The emission spectrum of the A–X system of the PbBr molecule in the region 4 600–5 900 Å has been obtained in the second order of a 21-ft concave grating spectrograph (15 000 lines per inch) with a dispersion of 1.25 Å/mm. A rotational analysis of four bands—(3, 2), (2, 2), (3, 1), and (4, 1)—of this system has been done, leading to the determination of the following rotational constants:[Formula: see text]The system appears to be similar to the A-X system of the PbCl molecule in the visible region, and a [Formula: see text] transition has been suggested.

NEW ELECTRONIC TRANSITIONS OF THE BH MOLECULE

1941 ◽  
Vol 19a (2) ◽  
pp. 27-31 ◽  
Author(s):  
A. E. Douglas
Keyword(s):  
Electronic Transitions ◽  
Lower State ◽  
Electron Configuration ◽  
Rotational Constants ◽  
Boron Trichloride ◽  
New States ◽  
Π State

In a discharge in helium with a trace of boron trichloride and hydrogen three new bands are found at 3415 Å, 3396 Å, and 3099 Å. Measurements of these bands show that they are due to two new electronic transitions of the BH molecule. The upper states of both transitions are previously unknown 1Σ+ states. The lower state of both transitions is the same and is a known 1Π state. The rotational constants of both new states have been determined and their electron configuration is suggested.

ROTATIONAL ANALYSIS OF THE VISIBLE BAND SYSTEM OF THE BiF MOLECULE

1962 ◽  
Vol 40 (9) ◽  
pp. 1077-1084 ◽  
Author(s):  
T. A. Prasada Rao ◽  
P. Tiruvenganna Rao
Keyword(s):  
Band System ◽  
High Dispersion ◽  
Rotational Analysis ◽  
Rotational Constants ◽  
Visible Band ◽  
System A

A rotational analysis of five bands, (1,0), (0,0), (0,1), (0.2), and (0,3), of the visible band system A of BiF has been carried out by photographing the bands under high dispersion (1.25 Å/mm). The analysis has shown that the bands arise from a 0+(3Σ−)–0+(3Σ−) transition. The rotational constants for the upper and lower states of the system are obtained.

A 3Σ–3Π transition of the SiO molecule

1970 ◽  
Vol 48 (12) ◽  
pp. 1436-1440 ◽  
Author(s):  
S. Nagaraj ◽  
R. D. Verma
Keyword(s):  
Quartz Tube ◽  
High Dispersion ◽  
Rotational Analysis ◽  
Rotational Constants ◽  
Single Sequence

The spectrum in the region 4200–4300 Å, attributed to the SiO molecule, has been excited strongly in a r.f. discharge through a mixture of argon and a trace of SiCl4 vapor flowing through a quartz tube. The spectrum consists of a single sequence Δν = 0. The 0–0 and 1–1 bands have been photographed at high dispersion. A rotational analysis of these bands shows that they involve a 3Σ–3II transition and not a 1Σ–3Π transition as reported earlier. The following rotational constants were determined:[Formula: see text]

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.

Spectrum of azulene. IV. Rotational analysis of the 0-0 band of the 3500 Ǻ transition

1968 ◽  
Vol 21 (12) ◽  
pp. 2835 ◽  
Author(s):  
AJ McHugh ◽  
DA Ramsay ◽  
IG Ross
Keyword(s):  
Fine Structure ◽  
Excited State ◽  
Type A ◽  
Resolving Power ◽  
Rotational Analysis ◽  
Type B ◽  
Rotational Constants ◽  
Multiple Line ◽  
Asymmetric Top ◽  
Low K

The bands of the 3500 Ǻ transition of azulene-do and azulene-ds show two unequal peaks 2.3 cm-l apart, followed by closely spaced fine structure. These bands have been analysed as type A bands of a planar, prolate asymmetric top. Rotational constants for both molecules in the excited state have been determined. The fine structure is due to multiple line coincidences in the high-J, low-K region of the qP branch. To each multiple line can be attributed a running number n = J+m, where m = J-K-1. Given sufficient resolving power, such "lines" should be rather commonly observed in type A and type B bands of large, planar, prolate molecules.

Rotational Analysis of B–X2 System of 208PbF

1972 ◽  
Vol 50 (18) ◽  
pp. 2206-2210 ◽  
Author(s):  
O. Nath Singh ◽  
I. S. Singh ◽  
O. N. Singh
Keyword(s):  
Second Order ◽  
Rotational Analysis ◽  
Rotational Constants ◽  
Concave Grating

The rotational analysis of the three bands (1,0), (0,0), and (0,1) of the B–X2 system of PbF has been carried out. The bands have been excited in a transformer discharge and photographed in the second order of a 35 ft concave grating spectrograph. The analysis has shown that the bands arise from a 2Σ+–2Π3/2 transition. The rotational constants of the upper and lower states have been determined.

High-resolution studies of the near-ultraviolet bands of oxygen: III: the system

1986 ◽  
Vol 64 (6) ◽  
pp. 726-732 ◽  
Author(s):  
B. Coquart ◽  
D. A. Ramsay
Keyword(s):  
High Resolution ◽  
Electron Configuration ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
Rotational Constants ◽  
Near Ultraviolet ◽  
Path Lengths

Ten bands of the [Formula: see text] system of oxygen have been observed in absorption using longer path lengths than in the earlier work of Herzberg (1953). Rotational analysis of the bands confirms that the A′ 3Δu state is an inverted state as expected from electron-configuration arguments. Rotational assignments are given for the [Formula: see text] and [Formula: see text] sub-bands with ν′ = 2–11; weaker [Formula: see text] sub-bands are identified for ν′ = 5–11. Sub-band origins and rotational constants are given for all the bands. The following derived molecular constants are obtained:[Formula: see text]A comparison of the frequencies of the diffuse bands of oxygen with the sub-band origins of the [Formula: see text] bands shows convincingly that the diffuse bands can be assigned to a weak (O2)2 complex in which one of the O2 molecules is excited to the A′ 3Δu state.

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