The eléctron donor/acceptor interactions of thiomorpholine (TM) with DDQ, CHL and TCNQ in chloroform as solvent have been produced stable complexes with general formula{ (TM)(acceptor)} with molar ratio 1:1 acceptor: donor. The elemental analysis (CHN), electronic spectra, photometric titration, infrared spectra as well as thermogravimetric analysis (TGA/DTG) were used to give known idea about the charge-transfer interaction between donating and accepting sites. Benesi-Hildebrand and its modification methods were applied to determination of association constant (K), molar absorbtivity (ɛ).