Difluoro [2.2] paracyclophanes Characterization by 1H, 13C and 19F NMR

Abstract The four isomers of difluoro[2.2]paracyclophane are uniquely identified on the basis of their 1 H, 13 C and 19 F NMR spectra. 13 C/ 12 effects on the 19 F chemical shifts were measured and a small transannular effect was detected.