BAND SPECTRUM AND STRUCTURE OF THE BCl MOLECULE

1941 ◽  
Vol 19a (11) ◽  
pp. 127-137 ◽  
Author(s):  
G. Herzberg ◽  
W. Hushley
Keyword(s):  
Fine Structure ◽  
Internuclear Distance ◽  
Ground State ◽  
Vibrational Structure ◽  
Sixth Order ◽  
Band Spectrum ◽  
Molecular Constants ◽  
Rotational Constants ◽  
New Formula

The 1Π−1Σ+ system of the BCl molecule has been photographed in the sixth order of a 20 ft. grating. The previous interpretation of the vibrational structure by Miescher (5) is slightly modified. The new formula for the Q heads of the B11Cl35 molecule is[Formula: see text]The fine structure of a number of bands has been measured and analysed, leading to the following accurate values for the rotational constants: B′e = 0.7054 cm.−1, α′e = 0.00820 cm.−1, B″e = 0.6838 cm.−1, α″e = 0.00646 cm.−1. The internuclear distance in the ground state is r″e = 1.716.10−8 cm. The molecular constants of BCl are compared with those of the iso-electronic molecules CS, PN, and SiO as well as with those of BBr, BCls, and BBr3.

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.

Vibration-rotation bands of trideuteromethyl iodide

1965 ◽  
Vol 288 (1412) ◽  
pp. 39-49 ◽  
Keyword(s):  
Fine Structure ◽  
Coupling Constants ◽  
Coriolis Coupling ◽  
Molecular Constants ◽  
Rotational Constants ◽  
Vibrational Levels ◽  
Theoretical Predictions ◽  
Vibration Rotation ◽  
Combination Bands

The rotational fine structure of six parallel and nine perpendicular vibration bands of tri­deuteromethyl iodide has been analysed, and molecular constants have been derived. These include the band origins, the rotational constants in different vibrational levels, the α A i and α B i values, and the Coriolis coupling constants ς i for the fundamental degenerate vibrations. The ς values for overtone and combination bands have been compared with values calculated from the ς i values of the fundamentals, and agree closely with previous theoretical predictions.

Vibration-rotation bands of nitrous oxide

1951 ◽  
Vol 208 (1094) ◽  
pp. 326-331 ◽  
Keyword(s):  
Nitrous Oxide ◽  
Fine Structure ◽  
Ground State ◽  
Wave Length ◽  
The Other ◽  
Resolving Power ◽  
Microwave Measurements ◽  
Rotational Constants ◽  
Infra Red ◽  
Vibration Rotation

The infra-red absorption of nitrous oxide gas near 4·5 μ has been re-investigated using high resolving power. The rotational fine structure has been split up and shown to involve two vibrational transitions, one due to absorption of a fundamental from the ground state, and the other to a π → π transition from an excited vibrational level. The transitions have been analyzed theoretically and rotational constants obtained. The results serve to emphasize the importance of using more precise wave-length standards for infra-red measurements than have been used hitherto, if the rotational constants are to be obtained with accuracy com­parable to that achieved by microwave measurements. Excellent agreement with the latter has now been found.

STRUCTURE OF THE BAND SPECTRUM OF THE CuBr MOLECULE: I. ROTATIONAL STRUCTURE OF THE C SYSTEM OF 63Cu81Br

1967 ◽  
Vol 45 (8) ◽  
pp. 2805-2807 ◽  
Author(s):  
P. Ramakoteswara Rao ◽  
K. V. S. R. Apparao
Keyword(s):  
Fine Structure ◽  
High Resolution ◽  
Structure Analysis ◽  
Band System ◽  
Rotational Structure ◽  
Band Spectrum ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
Fine Structure Analysis

The C band system of 63Cu81Br, lying in the region 3 900–4 600 Å, has been photographed in emission under high resolution and rotational analysis of the (2–0), (1–0), (0–0), (0–1), (0–2), and (1–3) bands carried out. The system is shown to involve a 1Σ(C1Σ)–1Σ(X1Σ) transition. The molecular constants of 63Cu81Br obtained from this fine-structure analysis are as follows:[Formula: see text]

Theoretical calculation of the low-lying electronic states of the LaH molecule

2014 ◽  
Vol 92 (9) ◽  
pp. 855-861 ◽  
Author(s):  
Salman Mahmoud ◽  
Mahmoud Korek
Keyword(s):  
Potential Energy ◽  
Internuclear Distance ◽  
Ground State ◽  
Electronic States ◽  
Electronic Energy ◽  
Centrifugal Distortion ◽  
Harmonic Frequency ◽  
Rotational Constants ◽  
Centrifugal Distortion Constants ◽  
First Time

The potential energy curves of the low-lying electronic states of the LaH molecule are reported via the CASSCF method with multireference calculations (single and double excitations with Davidson corrections). Twenty-four low-lying electronic states of the LaH molecule in the representation 2s+1Λ(+/−) below 20 000 cm−1 were investigated along with five lower electronic states in the Ω representation. The harmonic frequency ωe, the equilibrium internuclear distance Re, the rotational constants Be, and the electronic energy with respect to the ground state Te were calculated for these states. Twelve new electronic states are investigated in the present work for the first time that have not yet been observed experimentally. Using the canonical functions approach, the eigenvalues Ev, the rotational constants Bv, the centrifugal distortion constants Dv, and the abscissas of the turning points Rmin and Rmax were calculated for the investigated electronic states up to vibrational level v = 43.

HIGH-RESOLUTION RAMAN SPECTROSCOPY OF GASES: XVIII. PURE ROTATIONAL SPECTRA OF CYCLOPROPANE AND CYCLOPROPANE-d6

1964 ◽  
Vol 42 (11) ◽  
pp. 2259-2263 ◽  
Author(s):  
W. Jeremy Jones ◽  
B. P. Stoicheff
Keyword(s):  
Raman Spectroscopy ◽  
High Resolution ◽  
Raman Spectra ◽  
Internuclear Distance ◽  
Ground State ◽  
Rotational Constants ◽  
Rotational Spectra ◽  
Resolution Study

A high-resolution study of the rotational Raman spectra of cyclopropane and cyclopropane-d6 has yielded the values 0.66962 ± 0.00020 cm−1 and 0.46079 ± 0.00015 cm−1 for their ground-state rotational constants. From these values the C–C internuclear distance is determined to be 1.514 ± 0.002 Å.

ON THE SPECTRUM OF THE P2 MOLECULE

1940 ◽  
Vol 18a (8) ◽  
pp. 139-143 ◽  
Author(s):  
G. Herzberg ◽  
L. Herzberg ◽  
G. G. Milne
Keyword(s):  
Internuclear Distance ◽  
Ground State ◽  
Ultra Violet ◽  
Moment Of Inertia ◽  
Rotational Constants ◽  
Large Dispersion ◽  
The Moment

Five bands of the ultra-violet system of P2, with low v′ and v″ values, have been measured under large dispersion and analysed. They serve to determine much more accurately than heretofore possible the rotational constants Be″ and αe″, the moment of inertia Ie″, and the internuclear distance re″ of the P2 molecule in the ground state. The following values have been found: Be″ = 0.3031 cm.−1, αe″ = 0.00138 cm.−1, Ie″ = 92.36∙10−40gm.-cm.2, re″ = 1.895 10−8 cm.

A new predissociated 2Σ+ state of the BeCl molecule

1977 ◽  
Vol 55 (6) ◽  
pp. 582-588 ◽  
Author(s):  
M. Carleer ◽  
B. Burtin ◽  
R. Colin
Keyword(s):  
Excited State ◽  
High Resolution ◽  
Dissociation Energy ◽  
Intensity Distribution ◽  
Internuclear Distance ◽  
Ground State ◽  
Thermochemical Data ◽  
Molecular Constants ◽  
Equilibrium Internuclear Distance ◽  
A Value

Ten bands belonging to a new B2Σ+–X2Σ+ system of the BeCl molecule have been discovered in emission between 1990 and 2175 Å. The bands of both isotopes Be35Cl and Be37Cl have been photographed at high resolution and the most intense ones have been rotationally analyzed. Only three levels of the excited state have been observed and they present vibrational and rotational perturbations. The principal molecular constants of the new B2Σ+ state of Be35Cl are: v00 = 48 827.6, ΔG1/2 = 925.5, ΔG3/2 = 1212.7, Be = 0.7751, De = 3.5 × 10−6 cm−1, and the equilibrium internuclear distance is 1.7422 Å. The unusual intensity distribution in the bands can be tentatively interpreted as the result of an inverse predissociation which leads to a value of D″0 = 27 800 ± 500 cm−1 (3.45 ± 0.06 eV) for the dissociation energy of the ground state of the BeCl molecule. This value is at variance with thermochemical data.

FERMI DIAD 10°0 AND 02°0 OF NITROUS OXIDE

1956 ◽  
Vol 34 (11) ◽  
pp. 1147-1152 ◽  
Author(s):  
K. Narahari Rao ◽  
Harald H. Nielsen
Keyword(s):  
Nitrous Oxide ◽  
Fine Structure ◽  
Ground State ◽  
Molecular Constants

Measurement of the fine structure of the bands ν1 and 2ν20 of nitrous oxide has led to an evaluation of the centrifugal stretching constants of the Fermi diad 10°0 and 02°0. It was found that as compared to the value in the ground state, the change in the centrifugal stretching constant of the 02°0 level is much more than in the 10°0 level. This result has been discussed in relation to the theory of Nielsen, Amat, and Goldsmith (1956). The following revised values have been obtained for some of the molecular constants of N214O16:[Formula: see text]

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.

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