Studies on the Proton Magnetic Resonance Spectra in Aromatic Systems. XIV. On the meta <SUP>1</SUP>H and <SUP>13</SUP>C Chemical Shift of Monosubstituted Benzene and Pyridine Series

Abstract

Meta 1H and 13C chemical shifts of monosubstituted benzene and pyridine derivatives have been correlated with respect to the substituent constants σi and σπ, and following results are presented. a) The π-electronic contributions observed among both 1H and 13C shifts are positive. b) Above conclusions are also reliable in substituted pyridines.