Rotational Structure in the A2Σ+, B2Σ+, and a4Σ− – X2Π Transitions of GeF

1973 ◽  
Vol 51 (2) ◽  
pp. 125-143 ◽  
Author(s):  
R. W. Martin ◽  
A. J. Merer
Keyword(s):  
Matrix Element ◽  
Ground State ◽  
Electronic States ◽  
Second Order ◽  
Rotational Structure ◽  
Rotational Analysis ◽  
Rotational Constants ◽  
Intensity Enhancement ◽  
Perturbation Matrix

Rotational analysis of over 50 sub-bands of three emission transitions of 74GeF has given vibrational and rotational constants for the four lowest-lying electronic states of GeF. One of these is a 4Σ− state in Hund's case (a), where all four spin components have been identified. Extensive perturbations between this 4Σ− state and the B2Σ+ state have been analyzed in detail: the two states appear to interact mainly by a second-order mechanism through the so far uncharacterized σπ22Σ+ state, but the surprisingly large J dependence of the perturbation matrix element suggests that another mechanism, possibly involving the ground state, may contribute. Further perturbations, where the lines show an unusual intensity enhancement, appear in those sub-bands with B2Σ+ ν = 4 as upper state.

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.

ROTATIONAL ANALYSIS OF THE VISIBLE EMISSION BANDS OF THE PbF MOLECULE

1964 ◽  
Vol 42 (4) ◽  
pp. 690-695 ◽  
Author(s):  
K. Madhusudana Rao ◽  
P. Tiruvenganna Rao
Keyword(s):  
Band System ◽  
Second Order ◽  
Rotational Structure ◽  
Visible Emission ◽  
Rotational Analysis ◽  
Rotational Constants ◽  
Visible Band ◽  
System A ◽  
Concave Grating

The rotational structure of the (0, 0), (0, 1), (0, 2), and (1, 0) bands of the visible band system (A–X1) of PbF has been examined in the second order of a 21-ft concave grating spectrograph having a dispersion of 1.25 Å/mm. A rotational analysis of the bands has led to a determination of the rotational constants of the upper and lower states. From consideration of electron configurations it is suggested that the system arises from a [Formula: see text] transition which is a case c equivalent of [Formula: see text].

A 4Σ−–2Π TRANSITION OF THE SiF MOLECULE

1962 ◽  
Vol 40 (5) ◽  
pp. 586-597 ◽  
Author(s):  
R. D. Verma
Keyword(s):  
High Resolution ◽  
Ground State ◽  
Electronic States ◽  
Lower State ◽  
Rotational Analysis ◽  
Rotational Constants

The η bands of SiF, in the region 3300–3400 Å, have been photographed in emission at high resolution. A detailed rotational analysis has shown that these bands represent a 4Σ−–2Πτ transition. The lower state is the ground state of the molecule. The principal rotational constants of the upper and lower electronic states in cm−1 are as follows:[Formula: see text]A discussion of the electron configurations is also given.

Rotational Analysis of the A–X System of the SiCl Molecule

1971 ◽  
Vol 49 (4) ◽  
pp. 407-411 ◽  
Author(s):  
S. R. Singhal ◽  
R. D. Verma
Keyword(s):  
Ground State ◽  
Electronic States ◽  
Rotational Structure ◽  
Spin Coupling ◽  
Quartz Tube ◽  
Rotational Analysis ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Molecular Constants ◽  
Vibrational Levels

The A–X system of the SiCl molecule in the region 4500–6400 Å has been excited by an r.f. discharge through a mixture of argon and a trace of SiCl4 vapor, flowing through a quartz tube. Several red degraded and double headed bands with ν′ = 0, 1, 2, and 3 have been observed and the rotational structure of the 0-5, 0-6, 0-7, 0-8, 0-9, 0-10, 1-9, and 1-10 bands has been analyzed. The analysis shows that the bands arise from a 2Σ–2Π transition, 2Π being the ground state of the molecule. The molecular constants have been determined for both the electronic states. The spin coupling constant, Aν, of the X2Π vibrational levels has been found to follow an equation[Formula: see text]

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.

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.

scholarly journals Microwave Spectrum and Quadrupole Coupling Constants of 2-Bromothiophene

1975 ◽  
Vol 30 (4) ◽  
pp. 541-548 ◽  
Author(s):  
P. J. Mjöberg ◽  
W. M. Ralowski ◽  
S. O. Ljunggren
Keyword(s):  
Ground State ◽  
Second Order ◽  
Coupling Constants ◽  
Order Perturbation ◽  
Vibrationally Excited ◽  
Rotational Constants ◽  
Isotopic Species ◽  
Principal Axes ◽  
Quadrupole Coupling ◽  
Hyperfine Splittings

Abstract The microwave spectra of the two 79Br and 81Br isotopic species of 2-bromothiophene have been measured in the region 18000-40000 MHz.For both isotopic species, the rotational constants of the ground state and one vibrationally excited state were determined, as well as the centrifugal distortion coefficients of the ground state. The ground state rotational constants in MHz are as follows:C4H332S79Br C4H332S81BrA = 5403.432 ±0.111 5403.563 ±0.095,B = 1139.0689±0.0010 1126.5173±0.0011 C = 940.5142±0.0018 931.9315±0.0009.In order to perform a second-order perturbation treatment of the quadrupole interaction, the matrix elements of products of direction cosines in terms of the symmetric top wave functions have been derived. By the first-and second-order perturbation analysis of the hyperfine splittings of the rotational lines, the nuclear quadrupole coupling constants have been determined. The values in MHz areXaa = 592.7 ±1.5 493.7 ±1.5,Xbb = -295.3 ±0.6 -245.6 ±0.7, Xcc = -297.4 ±1.6 -248.1 ±1.6,Xab = 80 ±9 64±8 ,in the principal axes system of the molecule.

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.

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.

The absorption spectrum of gaseous hydrogen bromide in the schumann region I. Rotational analysis

1961 ◽  
Vol 263 (1313) ◽  
pp. 259-276 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Hydrogen Bromide ◽  
Electronic States ◽  
Gaseous Hydrogen ◽  
Rotational Structure ◽  
Resolving Power ◽  
Rotational Analysis ◽  
Region I

The absorption spectrum of gaseous hydrogen bromide has been photographed in the region 1180 to 1500 Å, using fourth and fifth orders of a 3 m grating. About forty bands have been observed. The resolving power sufficed for the study of most of the discrete rotational structure. The analysis reveals that few of the bands are related in vibrational progressions and shows rather that they are to be associated with atleast thirty new electronic states.

Sign in / Sign up

Export Citation Format

Share Document