AbstractThe13C and1H spectra of a series of aromatic ketones, ethers and keto‐ethers were studied using the lanthanide shift reagent (LSR) Yb(fod)3and the data analyzed using the lanthanide induced shift (LIS) ratio method. Studies were carried out on phenalenone, 6‐methoxyphenalenone, 1‐ and 2‐methoxynaphthalene, 1‐indanone, 5‐ and 6‐methoxy‐1‐indanone and flavone and the data obtained subjected to LSR‐substrate geometry analysis as a means of making13C assignments. The utility and limitations of the LSR method for making13C assignments is discussed and the LIS ratio method for LSR‐substrate geometry analysis i