Spin coupling of two identical complex ions. II. Comparison with the experimental data: fine structure and g values

1976 ◽  
Vol 65 (4) ◽  
pp. 1511-1515 ◽  
Author(s):  
G. Amoretti ◽  
V. Varacca
Keyword(s):  
Experimental Data ◽  
Fine Structure ◽  
Spin Coupling ◽  
Complex Ions

scholarly journals Spin-Spin Coupling Constants 1J(15N,11B) in Boron-Nitrogen Compounds. Experimental Data and DFT Calculations

2007 ◽  
Vol 62 (2) ◽  
pp. 220-224 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Oleg L. Tok
Keyword(s):  
Experimental Data ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Positive Sign ◽  
Nitrogen Compounds ◽  
Dft Methods ◽  
Spin Coupling Constants ◽  
Fermi Contact ◽  
Spin Spin Coupling ◽  
Boron Nitrogen

Boron-nitrogen compounds were studied with respect to indirect nuclear 15N-11B spin-spin coupling (1J(15N,11B)). Some new experimental data were determined for aminoboranes and tetra-Npyrrolylborate, and a variety of compounds with B-N single, double and triple bonds were examined using DFT methods for the calculation of 1J(15N,11B) at the B3LYP/6-311+G(d,p) level of theory. The calculations predict magnitude and sign of 1J(15N,11B) reasonably well, and the Fermi contact term was found to be dominant. A positive sign of 1J(15N,11B) was calculated in the case of 1-azacloso- dodecaborane(12), in contrast to all other compounds studied.

Hyperconjugation In Trialkylboranes Shown By Indirect Nuclear Spin-Spin Coupling Constants. Experimental Data And Density Functional Theory (Dft) Calculations

2005 ◽  
Vol 60 (3) ◽  
pp. 259-264 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Oleg L. Tok
Keyword(s):  
Experimental Data ◽  
Dft Calculations ◽  
Density Functional ◽  
Calculated Data ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Functional Theory ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling ◽  
C Nmr

Trimethylborane (1), triethylborane (2), 1,3-dimethyl-1-boracyclopentane (3), 1-methyl-1- boracyclohexane (4), 9-methyl- and 9-ethyl-9-borabicyclo[3.1.1]nonane [5(Me) and 5(Et)], and 1- boraadamantane (6) were studied by 11B and 13C NMR spectroscopy with respect to coupling constants 1J(13C,11B) and 1J(13C,13C). Results of DFT calculations at the B3LYP/6-311+g(d,p) level of theory show satisfactory agreement with the experimental data. Hyperconjugation arising from C-C σ bonds adjacent to the tricoordinate boron atom is indicated, in particular for 1-boraadamantane (6), by the optimised calculated structures, and by the experimental and calculated data 1J(13C,13C). The calculated magnitude of 1J(13C,1H) for carbon atoms adjacent to boron becomes significantly smaller if the optimised structures suggest hyperconjugative effects arising from these C-H bonds

A generalized empirical formula for half-lives of alpha-decay fine structure

2019 ◽  
Vol 28 (08) ◽  
pp. 1950067
Author(s):  
I. Sreeja ◽  
M. Balasubramaniam
Keyword(s):  
Experimental Data ◽  
Fine Structure ◽  
Ground State ◽  
Empirical Formula ◽  
Daughter Nucleus ◽  
Alpha Decay ◽  
Parent Nucleus ◽  
State Formula ◽  
Model Independent ◽  
Proton Radioactivity

A model-independent and [Formula: see text]-dependent four parameter formula has been recently proposed for the studies of one proton and two proton radioactivity. The same form of the formula with different parameter sets worked well for 1p and 2p emission indicating the fact that the similar phenomenological law is able to successfully reproduce both 1p as well as 2p emission half-lives suggesting the identical descriptions of these phenomena. Retaining the same form of the formula, its applicability is studied in this work for calculating the ground state as well as excited state [Formula: see text] emission. For this study, we consider 22 odd–odd nuclei, 31 odd–even nuclei, 52 even–odd nuclei, 88 even–even nuclei with the parent nucleus charge numbers in the range of [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text], respectively. For each of these subsets the emission of [Formula: see text] with different angular momentum values are considered. The general formula with four different parameter sets is proposed and the obtained results are compared with the experimental data. The study reveals that the general form of the proposed empirical formula is suitable for calculating the half-lives of 1p, 2p and [Formula: see text]-emission with different [Formula: see text]-values. With very minimal input like [Formula: see text]-values, and charge number of the daughter nucleus, this formula can be used as a handy tool for a systematic study as well as to plan new experiments.

Spin-Coupling in Heavily Nitrogen-Doped 4H-SiC

2009 ◽  
Vol 615-617 ◽  
pp. 343-346 ◽  
Author(s):  
D.V. Savchenko ◽  
Andreas Pöppl ◽  
Ekaterina N. Kalabukhova ◽  
Siegmund Greulich-Weber ◽  
Eva Rauls ◽  
...  
Keyword(s):  
Fine Structure ◽  
Theoretical Calculation ◽  
Line Width ◽  
Spin Coupling ◽  
Hopping Conductivity ◽  
Nitrogen Doped ◽  
Low Intensity ◽  
Fine Structure Splitting ◽  
Tentative Model ◽  
Structure Splitting

EPR and ESE in nitrogen doped 4H- and 6H-SiC show besides the well known triplet lines of 14N on quasi-cubic (Nc,k) and hexagonal (Nc,h) sites additional lines (Nx) of comparatively low intensity providing half the hf splitting of Nc,k. Frequently re-interpreted as spin-forbid¬den lines, arising from Nc,k pairs and triads or resulting from hopping conductivity, only re¬cent¬ly the theoretical calculation of the corresponding g-tensors lead to a tentative model of distant NC donor pairs on inequivalent lattice sites which are coupled to S = 1 assuming a fine-struc¬ture splitting too small to be observed in the EPR and ESE experiments. In this work, we pre¬sent ESE nutation measurements confirming S = 1 for the Nx center. Analysing the nutation frequencies in comparison with that of the Nc,k (S = 1/2) spectrum as well as the line width of ESE and EPR spectra we obtain a rough estimate between 5104 cm-1 and 50104 cm-1 for the fine-structure splitting demonstrating efficient spin-coupling between nitrogen donors in 4H-SiC.

Study on the Absorption Spectra of Ga2Se3:Co2+ Single Crystals

2009 ◽  
Vol 64 (12) ◽  
pp. 834-836
Author(s):  
Chao Ni ◽  
Yi Huang ◽  
Maolu Du
Keyword(s):  
Experimental Data ◽  
Fine Structure ◽  
Bond Length ◽  
Single Crystals ◽  
Crystal Field ◽  
Energy Levels ◽  
Crystal Field Parameter ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Cubic Crystal

Introducing the average covalent factor N and considering the interaction of the cubic crystal field, the spin-orbit coupling and Tree’s correction effects, the crystal field parameter Dq was calculated. Also the varying tendency of Dq with the bond length R was investigated. Using the complete diagonalizing method the energy levels of the fine structure of Ga2Se3:Co2+ single crystal were calculated and assigned. The calculated and assigned results are consistent with the experimental data

Theoretical views on Szilard Chalmers reactions in solid systems. II. Parent reformation by billiard-ball collisions

1968 ◽  
Vol 46 (20) ◽  
pp. 3201-3209 ◽  
Author(s):  
W. H. Wong ◽  
D. R. Wiles
Keyword(s):  
Experimental Data ◽  
Thermal Decomposition ◽  
Initial Energy ◽  
Projectile Energy ◽  
Metal Carbonyls ◽  
Present Stage ◽  
Complex Ions ◽  
Billiard Ball ◽  
Lower Limits ◽  
Mathematical Operations

The problem of billiard-ball replacement reactions of atoms centrally located in the molecule has been approached, using the approximation of simple two-body collisions. The reentry process has been separated into steps which can be handled by straightforward mathematical operations. Collision diameters for given energy transfer were calculated using an exponentially screened potential.Species treated include dicyclopentadienyl metals, arene metal carbonyls, and hexacoordinated complex ions, although the method is applicable to many other types of compound. An important result is that the probability of successful billiard-ball replacement is not sensitive to the initial energy, as long as this is not too low. It is concluded that this method is, at its present stage, most useful in calculating lower limits for billiard-ball reformation by following the projectile energy down to ca. 100 eV. Below this energy it is considered that thermal decomposition of the reformed molecule is likely. Results of the calculation are compared with experimental data, and further experiments are suggested by which the contribution of billiard-ball collisions may be directly assessed.

Spin coupling of two identical complex ions. I. Theory

1974 ◽  
Vol 61 (9) ◽  
pp. 3651-3657 ◽  
Author(s):  
G. Amoretti ◽  
V. Varacca
Keyword(s):  
Spin Coupling ◽  
Complex Ions
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