Ab Initio and 17O NMR Study of Aromatic Compounds with Dicoordinate Oxygen Atoms. 1. Methoxy- and (Methylenedioxy)benzene Derivatives

Article abstract of DOI:10.1021/j100382a020

17O NMR data at natural abundance in toluene-d8 at 74 deg C were obtained for aromatic compounds containing methoxy and methylenedioxy groups as side-chains substituents. 17O chemical shifts of this series of compounds are significantly influenced by both electronic and steric effects.Ortho electronic and steric subtituent chemical shift effects for methoxy and methylenedioxy groups were estimated.Ab inito calculations at the 4-31G level were used to determine geometries of the compounds to gain insight into the structural aspects of these compounds.A correlation between the calculated bond orders, P(C_Ar-O), and the 17O chemical shift was found.