Solid-state 13C NMR, X-ray, and quantum mechanical studies of the carbon chemical shift tensors of p-tolyl ether
This paper presents a detailed study of the principal components of the 13C chemical shift tensors in p-tolyl ether. The tensor components of a relative large number of carbon atoms are measured by using the two-dimensional magic angle turning (MAT) technique which allows for the determination of the principal components of the chemical shift tensors in powders. Theoretical calculations of the 13C chemical shieldings, using the X-ray molecular geometry, are used to assign the NMR resonances to individual carbon nuclei. The principal values of the chemical shift tensors permit assignments that would be unreliable if only the isotropic shift information is used. The chemical shift tensors of the carbons directly attached to the oxygen atom are very sensitive to the structural and electronic properties of the ether linkage. The combination of the 13C MAT experiment and theoretical chemical shieldings proves to be important in the study of electronic properties and molecular structure. © 1994 American Chemical Society.
