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.

Absorption spectrum of the Mg2 molecule

1970 ◽  
Vol 48 (7) ◽  
pp. 901-914 ◽  
Author(s):  
W. J. Balfour ◽  
A. E. Douglas
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
High Resolution ◽  
Potential Energy ◽  
Dissociation Energy ◽  
Ground State ◽  
Potential Energy Curve ◽  
Energy Curve ◽  
Vibrational Constants

The absorption spectrum of the Mg2 molecule, which occurs in a furnace containing Mg vapor, has been photographed with a high resolution spectrograph. The rotational structures of the bands have been analyzed and the rotational and vibrational constants of the two states determined. The bands are found to arise from a 1Σ–1Σ transition between a very lightly bonded ground state and a more stable excited state. The R.K.R. potential energy curve of the ground state, which has a dissociation energy of 399 cm−1, has been determined. The more important constants of the ground state are ωe = 51.12 cm−1, ωexe = 1.64 cm−1, re = 3.890 Å and those of the upper state are ωe = 190.61 cm−1, ωexe = 1.14 cm−1, re = 3.082 Å.

The Ground State and A2Π Excited State of Magnesium Deuteride

1975 ◽  
Vol 53 (15) ◽  
pp. 1477-1482 ◽  
Author(s):  
Walter J. Balfour ◽  
Hugh M. Cartwright
Keyword(s):  
Excited State ◽  
High Resolution ◽  
Emission Spectrum ◽  
Isotope Effect ◽  
Ground State ◽  
Visible Emission ◽  
Molecular Constants ◽  
Dissociation Energies ◽  
First Time ◽  
Π State

The visible emission spectrum of MgD has been reexamined at high resolution. Published analyses of the A2Π → X2Σ+ system have been extended and the data have been combined with observations in the B′2Σ+ → X2Σ+ system to provide information on the ground state levels ν = 3, 4, 5, and 6 for the first time. The following molecular constants (in cm−1) have been determined—for the A2Π state: ωc = 1154.75, ωcxc = 16.675, Bc = 3.2190, Dc = 9.64 × 10−5 and for the X2Σ+ state: ωc = 1077.71, ωcxc = 15.92, Bc = 3.0306, and Dc = 9.39 × 10−5. The dissociation energies in the A2Π and X2Σ+ states have been estimated to be ~ 15 500 cm−1 and ~ 11 500 cm−1 respectively. The MgH/MgD isotope effect and the Λ doubling in the A2Π state are discussed.

The electronic spectrum of the AlAu molecule

1963 ◽  
Vol 273 (1352) ◽  
pp. 133-144 ◽  
Keyword(s):  
High Resolution ◽  
Electronic Spectrum ◽  
Dissociation Energy ◽  
Internuclear Distance ◽  
Ground State ◽  
Single Bond ◽  
Kcal Mole

The spectrum of AlAu has been photographed both in emission and in absorption with high resolution in the region 3800 to 6500 A. Rotational analyses have been carried out for six bands of the A -X system and for two bands of the C-X system. The internuclear distance r e in the ground state is found to be 2·338 Å, considerably shorter than predicted from tables of single-bond covalent radii. The dissociation energy in the ground state, D ¨ 0 , is estimated to be 64 kcal/mole.

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.

Vibrational Analysis of the 2800 Å Band System of para-Dibromobenzene

1972 ◽  
Vol 50 (12) ◽  
pp. 1402-1408 ◽  
Author(s):  
S. M. Japar
Keyword(s):  
Excited State ◽  
High Resolution ◽  
Ground State ◽  
Band System ◽  
Vibrational Analysis ◽  
Type A ◽  
Strong Type ◽  
Type B ◽  
Sequence Structure ◽  
Extensive Sequence

The 2800 Å band system of p-dibromobenzene has been photographed under high resolution and an extended vibrational analysis has been carried out. The analysis is not inconsistent with the assignment of the system to a 1B2u ← 1Ag transition, by analogy with other p-dihalogenated benzenes. The observed spectrum can be explained in terms of a number of strong type-B vibronic bands and a considerably smaller number of type-A vibronic bands. The extensive sequence structure is adequately accounted for, and can be related to observations on other halogenated benzene molecules. Thirteen ground state and nine excited state fundamental vibrational frequencies have been assigned.

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.

scholarly journals Calculating Franck Condon Factor and Potential Curves for X2Σ+-A2Π System of BeBr Molecule

2015 ◽  
Vol 52 ◽  
pp. 5-10
Author(s):  
Adil Nameh Ayaash
Keyword(s):  
Excited State ◽  
Potential Function ◽  
Dissociation Energy ◽  
Ground State ◽  
Spectroscopic Properties ◽  
Spectroscopic Constants ◽  
Condon Factor ◽  
Condon Factors ◽  
Franck Condon ◽  
Potential Curves

The present work concerns by study of spectroscopic properties for Beryllium monobromide BeBr. Franck Condon Factor of BeBr molecule had been calculated theoretically for ground state X2Σ+ and excited state A2Π by special integrals by depending on spectroscopic constants for this molecule. The Dissociation energy and potential curves of this molecule is studied in this work by using Hua potential function, the results of potential curves and Franck Condon Factors converge with other researchers results.

scholarly journals On the Ionization Potential of Molecular Oxygen

1975 ◽  
Vol 53 (19) ◽  
pp. 1948-1952 ◽  
Author(s):  
James A. R. Samson ◽  
J. L. Gardner
Keyword(s):  
High Resolution ◽  
Ionization Potential ◽  
Molecular Oxygen ◽  
Dissociation Energy ◽  
Electron Spectroscopy ◽  
Rotational Structure ◽  
Appearance Potential ◽  
A Value ◽  
Vibrational Bands

The ionization potential of O2 has been measured by the technique of high resolution photo-electron spectroscopy taking into account the influence of rotational structure on the shape of the vibrational bands. A value of 12.071 ± 0.001 eV (1027.1 ± 0.1 Å) was found for the ionization potential. This value leads to a dissociation energy of D0(O2+X2Πg) = 6.661 ± 0.001 eV. A lowering of the ionization potential caused by a branch head when ΔN = −2 gave an appearance potential for ionization of 12.068 ± 0.001 eV (1027.4 ± 0.1 Å).

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