Electron Spin Resonance Studies of Petroleum Asphaltics
A considerable body of information about the electron spin resonance (ESR) properties of petroleum asphaltenes has developed during the past few years.(1–3) Among the basic parameters obtained by ESR measurements are N g, the number of unpaired spins per gram of material; |A|, the electron-nuclear spin coupling constant; and g, the effective Landé g-factor for the unpaired electron spins. A review of what is already known, and the addition of new data, may both clarify the present state of understanding of asphaltene ESR and stimulate further research in this area. The ESR studies briefly considered here may be divided into two parts: (1) measurements of the free-radical absorption, and (2) measurements of the ESR absorptions due to naturally occurring vanadium and synthetic vanadium chelate model systems.
KeywordsElectron Spin Resonance Electron Spin Resonance Study Vanadium Complex Vanadyl Complex Anisotropic Spectrum
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- 2.T. F. Yen, J. G. Erdman, and A. J. Saraceno, Bitumen, Terre, Asphalte, Peche 15, 141 (1964).Google Scholar
- 3.J. Q. Adams, K. H. Altgelt, R. L. LeTourneau, and L. P. Lindemen, Preprints, Am. Chem. Soc., Div. Petroleum Chem., 11 (2), B140 (1966).Google Scholar
- 4.T. F. Yen and J. P. Dickie, J. Inst. Petroleum 54, 1 (1968).Google Scholar
- 7.J. G. Erdman and J. P. Dickie, Preprints, Am. Chem. Soc., Div. Petroleum Chem., 9 (2), B69 (1964).Google Scholar
- 8.T. F. Yen and J. G. Erdman, in: “Encyclopedia of X-Rays and Gamma Rays” ( G. L. Clark, ed.), Reinhold Publishing Company, New York (1963), pp. 65–68.Google Scholar
- 15.C. L. Wolfe, E. C. Tynan, and T. F. Yen, Pittsburgh Conf. on Analytical Chemistry and Applied Spectroscopy, Paper No. 54, March 1967.Google Scholar
- 16.E. C. Tynan and T. F. Yen, Preprints, Am. Chem. Soc., Div. Petroleum Chem., 12 (2), A89 (1967).Google Scholar
- 21.G. B. Vaughan, E. C. Tynan, and T. F. Yen, 155th Natl. Mtg., Am. Chem. Soc., Div. Organic Chem., Paper No. 209, San Francisco, April 1968.Google Scholar