Electron Spin Delocalization in Feast-Type (Durham Route) Polyacetylene: Pulsed ENDOR Investigations

1987 ◽  
Vol 4 (8) ◽  
pp. 947-951 ◽  
Author(s):  
H Käss ◽  
P Höfer ◽  
A Grupp ◽  
P. K Kahol ◽  
R Weizenhöfer ◽  
...  
1986 ◽  
Vol 64 (4) ◽  
pp. 769-772 ◽  
Author(s):  
Donald R. Arnold ◽  
A. Martin de P. Nicholas ◽  
Kent M. Young

The linear relationship between the electron spin resonance hyperfine coupling constants (hfc) of the α- and β-hydrogens of para-substituted α-phenethyl radicals provides experimental evidence that the magnitude of both the α- and β -hfc is determined largely by the extent of spin delocalization in these benzylic systems. The [Formula: see text] scale, developed using substituted benzyl radicals, is shown to apply to phenethyl radicals as well.


1974 ◽  
Vol 27 (1) ◽  
pp. 213 ◽  
Author(s):  
Yau Yan. Lim

The interaction between bis(ethylxanthato)nickel(11) and pyridine and 4-picoline in nitrobenzene was studied by N.M.R. spectroscopy at 34�C. The 1 : 2 equilibrium constants and proton n.m.r, isotropic contact shifts were obtained. The electron spin delocalization mechanism in the 1 : 2 adduct was discussed.


1986 ◽  
Vol 64 (2) ◽  
pp. 270-276 ◽  
Author(s):  
A. Martin de P. Nicholas ◽  
Donald R. Arnold

Electron spin resonance (esr) hfc values of π-radicals are found to be linearly related to the stabilization energy due to spin delocalization. Application of this relationship to benzyl radicals permits the representation of σ•α values on an energy scale. Mulliken charges in the α- and β-spin systems are found to provide valuable information about factors governing the effects of substituents on spin delocalization in benzyl radicals. These effects can be rationalized by considering four types of spin–spin interactions involving σ- and π-electrons in the α- and β-spin systems. The Mulliken analysis shows that all substituents are stronger π α-acceptors (or weaker π α-donors) at the para position relative to the meta position. Similarly, in the 3 system the meta derivatives are the better acceptors. This may be understood in terms of the excess of π α-spin at the para-carbon and the excess of π β-spin at the meta-carbon. Similar effects are observed in the a framework.


1972 ◽  
Vol 11 (1) ◽  
pp. 134-137 ◽  
Author(s):  
R. A. Zelonka ◽  
M. C. Baird

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