Gerald W. Buchanan

A Carbon-13 Nuclear Magnetic Resonance Investigation of Some Substituted Methyl Phenyl Sulfides, Sulfoxides, and Sulfones

Carbon-13 chemical shifts for 33 methyl phenyl sulfides, sulfoxides, and sulfones are reported. Observed trends are discussed in terms of the steric and electronic influences of the substituent groups. Additivity correlations for para-disubstituted materials are noted. In general, the shieldings of methyl carbons bonded to sulfur are rather insensitive to the nature of the aromatic substituents. By contrast to the proton shieldings, the CH3SO and CH3SO2 carbons exhibit nearly identical chemical shifts.

Tricyclic Hydrocarbons. II. Carbon-13 Nuclear Magnetic Resonance Spectroscopy as a Method for Unambiguous Structure Determination

Carbon-13 n.m.r. spectroscopy is demonstrated to be unique as an unambiguous and general method for determining structure in a series of isomeric tricyclic benzenoid hydrocarbons. Observed carbon shieldings for the tricyclic materials are discussed and compared with those for related bicyclic and monocyclic compounds.