1Chemistry Department, College of Sciences, Bushehr University, Bushehr, I.R. Iran
2Chemistry Department, College of Sciences, Shiraz University, Shiraz 71454, I.R. Iran
The charge transfer (CT) complex formation of benzonitrile as acceptor with the aromatic donors o-, m-, p-xylene and ethylbenzene in CCl4 solutions is investigated by chemical shift measurements relative to an external reference. The equilibrium parameters, Q and DAD of their weak molecular complexes, as found numerically modified Cresswel- Allred (C-A) method, is compared with graphically Scatchard-Foster-Fyfe (Sc-F-F) method.