Hydrogen-Bonding Studies of Pyridine and o-Phenylphenol with Coal Asphaltenes by Multi-nuclei Magnetic Resonance

Abstract

Proton, carbon, and nitrogen-14 nuclear magnetic resonance studies are reported of hydrogen bonding between the OH proton of o-phenylphenol (OPP) and the nitrogen electron donor of pyridine (Py). Data are also reported on the hydrogen bonding of the acid and base components of coal-derived asphaltenes with the model system. Determination was made of the equilibrium constant of the 1:1 complex between OPP and Py from the proton NMR studies. Qualitative results are reported from the 13C and 14N studies of the model system (OPP-Py) with the individual asphaltene fractions. Because of the recent renewed interest in coal liquefaction this investigation may provide a starting point for future research.