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I. Preliminary studies of the chain-transfer constant of methylferrocene. II. Protonation of metallocenes. III. An Analysis of the N.M.R. spectra of substituted ferrocenes. IV. Experimental and theoretical studies of the charge distribution on the ferrocenyl carbinyl carbonium ion

Citation

Levenberg, Milton Irwin (1965) I. Preliminary studies of the chain-transfer constant of methylferrocene. II. Protonation of metallocenes. III. An Analysis of the N.M.R. spectra of substituted ferrocenes. IV. Experimental and theoretical studies of the charge distribution on the ferrocenyl carbinyl carbonium ion. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-09272002-144907

Abstract

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PART I:

Styrene monomer containing various concentrations of methylferrocene was allowed to polymerize at 70?C. The average molecular weight of the resulting polystyrene was determined, and the chain transfer constant of methylferrocene then calculated. The constant was found to be 0.7 x 10[superscript -4], indicating some contribution to the stability of the methyl free radical by the ferrocenyl group.

The reactivity of methylferrocene to free radical attack is discussed, and the copolymerization of methylferrocene with styrene is considered.

PART II:

The n. m. r. spectra of ferrocene, ruthenocene, and osmocene in boron trifluoride monohydrate have been studied. Accurate measurements of relative peak areas and positions are reported. The species responsible for the n.m.r. spectra are discussed.

PART III:

A detailed analysis of the n. m. r. spectra of a series of alkylacetylferrocenes in a variety of solvents has been carried out. This has allowed a determination of the coupling constants between the various protons in these substances. For protons attached to the same ring, the following values are generally observed: J[subscript 23] ~ 2.5 cps and J[subscript 24] ~ 1.3 cps. The magnetic anisotropy of the carbonyl group in 2-acetyl-1, 1'-trimethylene ferrocene is also discussed.

PART IV:

The existence of the stable ferrocenylcarbinyl carbonium ion has been demonstrated by freezing point depression measurements in concentrated sulfuric acid. The n. m. r. spectrum of the carbonium ion has been observed and the chemical shifts of its protons relative to those of methylferrocene have been measured. The factors influencing the proton chemical shifts are discussed.

Techniques of molecular orbital calculations applicable to ferrocenyl systems are discussed and the results of a series of molecular orbital calculations on the ferrocenylcarbinyl carbonium ion are presented. The chemical shifts of the protons on the carbonium ion are predicted from the molecular orbital calculations, and the predictions are compared with the experimentally measured chemical shifts. The agreement is not as good as could be desired.

Item Type:Thesis (Dissertation (Ph.D.))
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Richards, John H.
Thesis Committee:
  • Unknown, Unknown
Defense Date:25 March 1965
Record Number:CaltechETD:etd-09272002-144907
Persistent URL:http://resolver.caltech.edu/CaltechETD:etd-09272002-144907
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:3794
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:27 Sep 2002
Last Modified:26 Dec 2012 03:03

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