New Results on the B2Σ+, b4Σ−, and X2Π States of PO

1975 ◽  
Vol 53 (4) ◽  
pp. 411-419 ◽  
Author(s):  
R. D. Verma ◽  
S. R. Singhal
Keyword(s):  
Extensive Study ◽  
Spin Coupling ◽  
Rotational Analysis ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Molecular Constants ◽  
Π State

An extensive study of the β system of the PO molecule has been carried out. The rotational analysis of 23 bands has yielded the constants of the ν = 0–9 levels of the B2Σ+ state and of the ν = 0–11 levels of the X2Π state with a precision higher than previous measurements. The spin coupling constant, Aν, evaluated for the 12 levels of X2Π is found to follow the equation Aν = 224.03 + 0.18ν–0.013ν2. The perturbations observed in the B2Σ (ν = 6 and 7) levels have been interpreted as being caused by a 4Σ− state and the B′2Π state. A deperturbation calculation has been carried out to evaluate the molecular constants of the PO molecule in the 4Σ− state. Several new bands were also observed; some of these belong to the β and B′–X systems and others are left unassigned.

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 Spectrum of AsF in the Near Vacuum Ultraviolet and Near Infrared Regions

1972 ◽  
Vol 50 (12) ◽  
pp. 1230-1251 ◽  
Author(s):  
D. S. Liu ◽  
W. E. Jones
Keyword(s):  
Relative Position ◽  
Ground State ◽  
Near Infrared ◽  
Vacuum Ultraviolet ◽  
Vibrational Analysis ◽  
Spin Coupling ◽  
Rotational Analysis ◽  
Coupling Constant ◽  
Spin Coupling Constant

Three singlet–triplet transitions, b1Σ+−X3Σ−, c1Π–X3Σ−, and d1Π–X3Σ−, and two 3Π–X3Σ− transitions attributed to the molecule AsF, have been found in the regions 1900–2300 Å and 7000–7400 Å. The vibrational analysis for the observed systems and the rotational analysis of the singlet–triplet transitions are complete. The analysis shows that the ground state X3Σ− belongs to Hund's case c with a spin coupling constant λ of about 70 cm−1. The analysis of the observed transitions and a discussion of the relative position and molecular configurations of the observed states are presented.

An estimate of the spin–spin coupling constant, 1J(1H,13C), in gaseous benzene

1996 ◽  
Vol 74 (8) ◽  
pp. 1524-1525 ◽  
Author(s):  
Ted Schaefer ◽  
Guy M. Bernard ◽  
Frank E. Hruska
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Dielectric Constant ◽  
Magnetic Resonance ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling ◽  
Gaseous Benzene

An excellent linear correlation (r = 0.9999) exists between the spin–spin coupling constants 1J(1H,13C), in benzene dissolved in four solvents (R. Laatikainen et al. J. Am. Chem. Soc. 117, 11006 (1995)) and Ando's solvation dielectric function, ε/(ε – 1). The solvents are cyclohexane, carbon disulfide, pyridine, and acetone. 1J(1H,13C)for gaseous benzene is predicted to be 156.99(2) Hz at 300 K. Key words: spin–spin coupling constants, 1J(1H,13C) for benzene in the vapor phase; spin–spin coupling constants, solvent dielectric constant dependence of 1J(1H,13C) in benzene; benzene, estimate of 1J(1H,13C) in the vapor; nuclear magnetic resonance, estimate of 1J(1H,13C) in gaseous benzene.

Rotational Analysis of the lΠ–XlΣ+ System of C80Se

1974 ◽  
Vol 52 (9) ◽  
pp. 813-820 ◽  
Author(s):  
René Stringat ◽  
Jean-Paul Bacci ◽  
Marie-Hélène Pischedda
Keyword(s):  
Emission Spectrum ◽  
Ground State ◽  
High Frequency ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
High Frequency Discharge ◽  
Perturbed State ◽  
Simple Evaluation ◽  
Π State

The strongly perturbed 1Π–X1Σ+ system of C80Se has been observed in the emission spectrum of a high frequency discharge through selenium and carbon traces in a neon atmosphere. The analysis of five bands yields, for the molecular constants of the ground state, the values Be″ = 0.5750 cm−1, [Formula: see text], αe″ = 0.00379 cm−1, re″ = 1.676 Å, ΔG″(1/2) = 1025.64 cm−1, and ΔG″(3/2) = 1015.92 cm−1. The numerous perturbations in the 1Π state prohibit the simple evaluation of the constants of the perturbed state and of the perturbing ones.

Form of the dihedral angle dependence of the spin-spin coupling constant JHNNH

1989 ◽  
Vol 25 (3) ◽  
pp. 338-341
Author(s):  
L. M. Kapkan ◽  
A. Yu. Chervinskii ◽  
T. M. Pekhtereva ◽  
Yu. I. Smirnov ◽  
A. F. Dmitruk
Keyword(s):  
Dihedral Angle ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Angle Dependence ◽  
Spin Spin Coupling

Temperature dependence of the carbon-13 proton spin-spin coupling constant in gaseous methane

1987 ◽  
Vol 61 (6) ◽  
pp. 1423-1430 ◽  
Author(s):  
B. Bennett ◽  
W.T. Raynes
Keyword(s):  
Temperature Dependence ◽  
Proton Spin ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Spin Spin Coupling

The proximate spin–spin coupling, 5J(F,CH3), as a quantitative conformational indicator in alkylfluorobenzenes and related compounds

1986 ◽  
Vol 64 (8) ◽  
pp. 1602-1606 ◽  
Author(s):  
Ted Schaefer ◽  
Rudy Sebastian ◽  
Glenn H. Penner ◽  
S. R. Salman
Keyword(s):  
Nuclear Spin ◽  
Spin Coupling ◽  
Torsional Angle ◽  
Rotational Behaviour ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Spin Spin Coupling ◽  
Torsional Potentials ◽  
Derivatives Of ◽  
Related Compounds

The through-space or proximate nuclear spin–spin coupling constant, 5J(F,CH3) = 5J, between methyl protons and ring fluorine nuclei in alkylfluorobenzenes is postulated as [Formula: see text] θ being the torsional angle for the [Formula: see text] bond. A and B are obtained from the known internal rotational behaviour in 2,6-difluoroethylbenzene and the corresponding cumene derivative. The parameterization is tested on the observed 5J in derivatives of 2,4,6-tri-tert-butyl- and 2,4,6-tri-isopropyl-fluorobenzene, in 2-chloro-6-fluoroisopropylbenzene, 2,6-difluoro-α-methylstyrene, and N-methyl-8-fluoroquinolinium halides. A prediction is made for 5J in 2,6-difluoro-tert-butylbenzene. It appears that the present parameterization allows the derivation of approximate torsional potentials from proximate couplings, for example in α,α-dimethyl-2,6-difluorobenzyl alcohol.

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