Rotational and hyperfine structure in the A6Σ+–X6Σ+ electronic transition of MnO

1980 ◽  
Vol 58 (5) ◽  
pp. 642-656 ◽  
Author(s):  
R. M. Gordon ◽  
A. J. Merer
Keyword(s):  
Hyperfine Structure ◽  
Electron Spin ◽  
Ground State ◽  
Electronic Transition ◽  
High Dispersion ◽  
High Electron ◽  
Parallel Polarization ◽  
Avoided Crossing ◽  
New Type ◽  
Great Complexity

The (0,0), (0,1), and (1,0) bands of the A6Σ+–X6Σ+ transition of MnO near 5500 Å have been photographed at high dispersion, and partial rotational analyses carried out. The spectrum is unusually complicated because of the high electron multiplicity, the manganese hyperfine structure, and extensive rotational perturbations. It is found that hyperfine perturbations frequently accompany the rotational perturbations. These are a new type of perturbation, resulting from a mixing of the F3 and F4 electron spin components in the upper state through hyperfine matrix elements of the type ΔN = 0, ΔJ ± 1, ΔF = 0 as a result of rotational perturbations. Extra lines, obeying the selection rules ΔJ = 0, ± 2, are induced: these give the energy separations of the F3 and F4 electron spin components of the ground state. As a result it has been possible to determine the electron spin fine structure parameters for the two states despite the parallel polarization of the electronic transition. The reason for the great complexity of the A6Σ+ ν = 0 level is the occurrence of a large avoided crossing near N = 26 with a level which is possibly a highly excited vibrational level of the ground state. The ground state Mn—O bond length is r0 = 1.6477 Å, and ΔG1/2(X6Σ+) = 832.41 cm−1.

Resolved hyperfine structure in the C–X electronic transition of VO. An internal hyperfine perturbation in the C4Σ− state

1981 ◽  
Vol 59 (2) ◽  
pp. 266-270 ◽  
Author(s):  
W. H. Hocking ◽  
A. J. Merer ◽  
D. J. Milton
Keyword(s):  
Hyperfine Structure ◽  
Electron Spin ◽  
Ground State ◽  
Electronic Transition ◽  
Laser Excitation ◽  
Magnetic Hyperfine ◽  
Excitation Spectra ◽  
Contact Parameter ◽  
Fermi Contact

New grating and laser excitation spectra of VO show resolved nuclear hyperfine structure in the lines of the F1 and F4 electron spin components in the C4Σ−–X4Σ−electronic transition. It is shown that the C4Σ− state has a sizeable hyperfine structure, with the Fermi contact parameter bF (the coefficient of I∙S in the magnetic hyperfine Hamiltonian) equal to −0.00773 cm−1. Another internal hyperfine perturbation, of the type described by Richards and Barrow for the ground state, occurs in the C4Σ−state near N = 5; the line doublings are consistent with the Fermi contact parameter derived from the F1 and F4 lines.

ROTATIONAL ANALYSIS OF THE γ SYSTEM OF THE PO MOLECULE

1958 ◽  
Vol 36 (11) ◽  
pp. 1526-1535 ◽  
Author(s):  
K. Suryanarayana Rao
Keyword(s):  
Ground State ◽  
Electronic Transition ◽  
Lower State ◽  
High Dispersion ◽  
Rotational Analysis ◽  
Small Perturbations ◽  
Rotational Constants ◽  
The One

The bands of the γ system of the PO molecule have been photographed under high dispersion (0.35 Å/mm). A rotational analysis of the 0–0, 0–1, and 1–0 bands is given, which differs from the one previously given by Sen Gupta. In addition, four more bands, namely, the 1–2, 2–1, 2–3, and 2–4 bands, have been analyzed. The bands are attributed to the electronic transition, A3Σ–X2Πreg, the lower state being the ground state of the molecule. The new rotational constants for the ground state are the following:[Formula: see text]The spin doubling in the upper state is small. Perturbations in the v = 0 level of the upper state, which were not reported previously, are observed and discussed. They supply a welcome confirmation of the correctness of the analysis here presented.

Ground-State Hyperfine Structure ofDy165

1968 ◽  
Vol 165 (4) ◽  
pp. 1360-1362 ◽  
Author(s):  
Alan T. Ramsey ◽  
Sanford Stein
Keyword(s):  
Hyperfine Structure ◽  
Ground State

A meta-analysis and review examining a possible role for oxidative stress and singlet oxygen in diverse diseases

2017 ◽  
Vol 474 (16) ◽  
pp. 2713-2731 ◽  
Author(s):  
Athinoula L. Petrou ◽  
Athina Terzidaki
Keyword(s):  
Oxidative Stress ◽  
Excited State ◽  
Singlet Oxygen ◽  
Ground State ◽  
Meta Analysis ◽  
Common Mechanism ◽  
High Electron ◽  
A Value ◽  
First Excited State

From kinetic data (k, T) we calculated the thermodynamic parameters for various processes (nucleation, elongation, fibrillization, etc.) of proteinaceous diseases that are related to the β-amyloid protein (Alzheimer's), to tau protein (Alzheimer's, Pick's), to α-synuclein (Parkinson's), prion, amylin (type II diabetes), and to α-crystallin (cataract). Our calculations led to ΔG≠ values that vary in the range 92.8–127 kJ mol−1 at 310 K. A value of ∼10–30 kJ mol−1 is the activation energy for the diffusion of reactants, depending on the reaction and the medium. The energy needed for the excitation of O2 from the ground to the first excited state (1Δg, singlet oxygen) is equal to 92 kJ mol−1. So, the ΔG≠ is equal to the energy needed for the excitation of ground state oxygen to the singlet oxygen (1Δg first excited) state. The similarity of the ΔG≠ values is an indication that a common mechanism in the above disorders may be taking place. We attribute this common mechanism to the (same) role of the oxidative stress and specifically of singlet oxygen, (1Δg), to the above-mentioned processes: excitation of ground state oxygen to the singlet oxygen, 1Δg, state (92 kJ mol−1), and reaction of the empty π* orbital with high electron density regions of biomolecules (∼10–30 kJ mol−1 for their diffusion). The ΔG≠ for cases of heat-induced cell killing (cancer) lie also in the above range at 310 K. The present paper is a review and meta-analysis of literature data referring to neurodegenerative and other disorders.

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