Collect. Czech. Chem. Commun. 1990, 55, 2131-2137

Chemical shifts of charge-transfer complexes and Buckingham equation

Mahboob Mohammad, Ather Yaseen Khan, Tariq Mahmood, Ismat Fatima, Riffat Shaheen and Rashid Iqbal

Electrochemistry Group, Chemistry Department, Quaid-i-Azam University, Islamabad, Pakistan


The 1H NMR spectra of the charge-transfer complex of 1-ethyl-4-methoxycarbonylpyridinium iodide have been recorded in various dipolar aprotic solvents. An attempt is made to interpret the chemical shifts in terms of Buckingham's reaction field equation for spherical cavities. A linear dependence has been found between the δ(2,6) values and the square of dielectric function for a spherical cavity, which confirms the validity of the Buckingham equation for this class of compounds.