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.

New electronic transitions of the C2 molecule in absorption in the vacuum ultraviolet region

1969 ◽  
Vol 47 (24) ◽  
pp. 2735-2743 ◽  
Author(s):  
G. Herzberg ◽  
A. Lagerqvist ◽  
C. Malmberg
Keyword(s):  
Ground State ◽  
Vacuum Ultraviolet ◽  
Rydberg States ◽  
The Other ◽  
Electronic Transitions ◽  
Lower State ◽  
Ultraviolet Region ◽  
New States ◽  
Vacuum Ultraviolet Region ◽  
Vibrational Constants

Three new electronic transitions of the C2 molecule have been observed in absorption in the region 1300–1450 Å. The system of shortest wavelength is readily identified as a 1Πu–1Σg+ transition; the lower state is the ground state X1Σg+ of the molecule. The other two systems arise by absorption from the low-lying a3Πu state; the upper states are new 3Σg− and 3Δg states. Rotational and vibrational constants of the three new states have been determined. The new states are Rydberg states. Their correlation to the separated atoms is briefly discussed.

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.

A NEW BAND SYSTEM OF THE P2 MOLECULE ANALOGOUS TO THE LYMAN–BIRGE–HOPFIELD BANDS OF N2

1958 ◽  
Vol 36 (5) ◽  
pp. 565-570 ◽  
Author(s):  
A. E. Douglas ◽  
K. Suryanarayana Rao
Keyword(s):  
Excited States ◽  
Ground State ◽  
Singlet State ◽  
Band System ◽  
Excited Singlet State ◽  
Lower State ◽  
High Dispersion ◽  
Electron Configuration ◽  
Excited Singlet ◽  
New System

Five bands of a new band system of P2 have been photographed at high dispersion and analyzed. The upper state of the system is a 1П0 state and lies lower than any previously known excited singlet state. The lower state of the new system is the ground state of P2 and the analysis of the new bands has given improved constants for this state. The new system appears to be the analogue of the Lyman–Birge–Hopfield bands of N2. The electron configuration of the low excited states of P2 and of related molecules is discussed.

BAND SPECTRUM AND STRUCTURE OF THE CH+ MOLECULE; IDENTIFICATION OF THREE INTERSTELLAR LINES

1942 ◽  
Vol 20a (6) ◽  
pp. 71-82 ◽  
Author(s):  
A. E. Douglas ◽  
G. Herzberg
Keyword(s):  
Ground State ◽  
Band System ◽  
Lower State ◽  
Band Spectrum ◽  
Interstellar Space ◽  
Molecular Constants ◽  
Vibrational Levels ◽  
State Formula ◽  
Heat Of Dissociation ◽  
Π State

In a discharge through helium, to which a small trace of benzene vapour is added, a new band system of the type 1Π – 1Σ is found which is shown to be due to the CH+ molecule. The R(0) lines of the 0–0, 1–0, and 2–0 bands of the new system agree exactly with the hitherto unidentified interstellar lines 4232.58, 3957.72, 3745.33 Å, thus proving that CH+ is present in interstellar space. At the same time this observation of the band system in absorption shows that the lower state 1Σ is the ground state of the CH+ molecule. The new bands are closely analogous to the 1II – 1Σ+ BH bands. The analysis of the bands leads to the following vibrational and rotational constants of CH+ in its ground state: [Formula: see text], Be″ = 14.1767, αe″ = 0.4898 cm.−1. The internuclear distance is re″ = 1.1310∙10−8 cm. (for further molecular constants see Table V). From the vibrational levels of the upper 1Π state the heat of dissociation of CH+ can be obtained within fairly narrow limits: D0(CH+) = 3.61 ± 0.22 e.v. From this value the ionization potential of CH is derived to be I(CH) = 11.13 ± 0.22 e.v. The bearing of this value on recent work on ionization and dissociation of polyatomic molecules by electron impacts is briefly discussed.

Etats Rydberg de NS. Etude du domaine spectral 2400–1750 Å

1976 ◽  
Vol 54 (18) ◽  
pp. 1909-1923 ◽  
Author(s):  
Michel Vervloet ◽  
Alain Jenouvrier
Keyword(s):  
Energy Level ◽  
Relative Position ◽  
Rydberg States ◽  
Energy Level Diagram ◽  
Electronic Transitions ◽  
Complete Analysis ◽  
Molecular Constants ◽  
Π State ◽  
Potential Curves

Five electronic transitions, C2Σ+–X2Π, I2Σ+–X2Π, E2Π–X2Π, J2Σ+–X2Π, and F2Δ–X2Π of NS have been observed in the region 1750–2400 Å. The complete analysis of these transitions has been carried out. The molecular constants of the C2Σ+, E2Π, J2Σ+, and F2Δ Rydberg states are given. Many perturbations in the rotational structures (ν = 1 and 2 of C2Σ+, ν = 0 of E2Π) and predissociations in the levels ν = 0 J2Σ+ and F2Δ are observed. The perturbation in the level ν = 0 of the E2Π state is described, the perturbing level being ν = 11 of the H2Π valence state.The most important results are given in the tables of constants. An energy level diagram and potential curves show the relative position of the different states. All the observed states of NS are finally compared with those of PO.

THE ABSORPTION SPECTRUM OF BO2

1961 ◽  
Vol 39 (12) ◽  
pp. 1738-1768 ◽  
Author(s):  
J. W. C. Johns
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
Detailed Analysis ◽  
Ground State ◽  
Flash Photolysis ◽  
Electronic Transitions ◽  
Molecular Constants ◽  
Boron Trichloride ◽  
Symmetric Molecule ◽  
First Excited State

The boron flame bands have been observed in absorption during the flash photolysis of mixtures of boron trichloride and oxygen. Detailed analysis of the spectrum has shown that the bands arise from two electronic transitions in the linear symmetric molecule BO2, [Formula: see text] and A2Πu−X2Πg. The main molecular constants, in cm−1 except for r0, are summarized below:[Formula: see text]Both 2Π states show the Renner effect. In the ground state the Renner parameter, εω2, was found to be −92.2, whereas in the first excited state it is much smaller, −13.1 cm−1.

The emission spectrum of ReO between 375 and 875 nm: A classification based on rotational analysis and Re16O/Re18O isotope shifts

1984 ◽  
Vol 62 (12) ◽  
pp. 1524-1537 ◽  
Author(s):  
Walter J. Balfour ◽  
Ram. S. Ram
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Electronic States ◽  
Electronic Transitions ◽  
Lower State ◽  
Rotational Analysis ◽  
Isotope Shifts ◽  
Isotopic Shifts

The emission spectrum of the ReO molecule has been photographed under high resolution between 375 and 875 nm. In addition to the 711.9 and 404.5 nm systems previously studied a large number of new electronic transitions have been classified on the basis of Re16O/Re18O isotopic shifts. The rotational structures of 18 bands of Re16O and 1 band of Re18O have been analyzed. Two low-lying electronic states in addition to the known common lower state of the 711.9 and 404.5 nm systems have been identified.

C2Πr – X2Σ+ transition of AlO

1983 ◽  
Vol 61 (9) ◽  
pp. 1347-1358 ◽  
Author(s):  
M. Singh ◽  
M. D. Saksena
Keyword(s):  
High Resolution ◽  
Rotational Structure ◽  
Rotational Constants ◽  
First Time ◽  
Π State

Several bands of the C2Πr – X2Σ+transition of AlO in the region 2800–3400 Å have been photographed at high resolution. A unique and unambiguous analysis of the rotational structure has been done for the first time for the 2–0, 1–0, 2–1, 0–0, 1–1, 0–1, 1–2, and 0–2 bands of this system. Fairly accurate rotational constants Beff and Deff have been determined for the ν = 2, 1, and 0 levels of the C2Πr state. Severe rotational perturbations have been observed in the C2Π, state.Equilibrium rotational constants (in cm−1) of the C2Π, state are Be ≈ 0.6049 and αe ≈ 0.0046.

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.

New spectrum of the SiO+ molecule

1968 ◽  
Vol 46 (14) ◽  
pp. 1597-1602 ◽  
Author(s):  
S. Nagaraj ◽  
R. D. Verma
Keyword(s):  
Rotational Structure ◽  
Lower State ◽  
Weak Band ◽  
Rotational Constants

A new spectrum of SiO+ in the region 4300–4100 Å has been obtained by a r-f. discharge through a flowing mixture of argon and SiCl4 which contained a trace of oxygen. This spectrum is mainly a long sequence Δν = 0. The rotational structure of the three bands 0–0, 1–1, and 2–2 has been analyzed and the rotational constants of the upper and lower states are determined.The known spectrum of SiO+ in the region around 3840 Å (Woods 1943) has also been obtained, with improved intensity under the above conditions and has been reanalyzed. It is found that the earlier numbering of the lines of this system is wrong by one unit and that the lower state of these bands and the upper state of the new bands represent the same state. The weak band, which was analyzed by Woods as 1–1, appears to fit as 2–2 according to the new analysis.Rotational constants of the three 2Σ states, which are named X, A, and B, are shown below (in cm−1):[Formula: see text]A discussion on electron configurations has also been included.

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