Steadman, Vivian Louise (1967) Some factors which affect the spin densitites of protons, with particular emphasis on the β-protons of cyclobutenyl. Master's thesis, California Institute of Technology. http://resolver.caltech.edu/CaltechTHESIS:05072010-160004325
Both first-order and variational valence bond calculations were made to estimate the ESR hyperfine splittings of the β-protons of cyclobutenyl. The ESR spectrum of the radical has not been obtained; but on the basis of these calculations, it is anticipated that the β-proton splittings will be large and in the range 42g to 101g. The first-order results indicate considerably larger splittings than the variational calculation; this situation was shown to be in marked contrast with another valence bond calculation on a free radical containing β-protons. Possible inequality in the β-proton splittings of cyclobutenyl at low temperatures was also discussed. The dependence of the spin densities of β-protons on π-electron excitation energies (in appropriate free radicals) was discovered and was shown to reduce the size of the β-proton hyperfine splittings. The agreement with experiment was satisfactory. The transformation between the vector-coupling states for an eight electron system and its canonical states was obtained. The canonical states were found to be especially amenable to computer computations, involving the non-overlap, empirical valence bond theory. The reasons for the suitability of the use of vector-coupling functions in configuration interaction in the valence bond theory were discussed. A case was presented in which it appeared desirable to distribute the antisymmetrical spatial components of the ground-state wave function somewhat differently in space than that of the symmetrical spatial components. An anomaly in the ESR spectra of irradiated benzene was deduced from theoretical considerations.
|Item Type:||Thesis (Master's thesis)|
|Degree Grantor:||California Institute of Technology|
|Division:||Chemistry and Chemical Engineering|
|Thesis Availability:||Public (worldwide access)|
|Defense Date:||14 December 1966|
|Default Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||18 Aug 2010 18:41|
|Last Modified:||26 Dec 2012 03:25|
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