Evaluation of New Substituent Parameters to Explain 13C Chemical Shift for para-Substituents in Benzene Ring

Department of Chemistry, Sambalpur University. Jyoti Vihar, Burla- 768 017

The ¹³C chemical shift data of 1,4-distributed benzenes have been used to evaluate para-substituent constants (\(\alpha\)\(_x^4\) and \(\beta\)\(_x^4\)) and their applicability has been examined in 39 different sets of data. These parameters have been found highly suitable to correlate the ¹³C chemical shifts of aromatic, aliphatic and heterocyclic systems.