Abstract: The interactions of iodonium salt with amines in ground state and excited state have been investigated. The formation of ground state and excited charge transfer complexes between iodonium salt as electron acceptor and amines as electron donors was observed. In the case of diphenyliodonium chloride (DPIOC)/triethylamine (TEA) system, the complex formed was determined to be 1:1 molar ratio and its association constant and molar extinction coefficient were equal to 2.2×10 (mol/l)^-1 and 2.8×10³ mol^-1·1·cm^-1 respectively. The experimental results also showed that with increasing of electron-donating ability of amines, the absorption maximum of charge transfer complex occurs a red-shift, however, with increasing of steric volume of amines, the molar extinction coefficient decreases due to the unfavorable steric hindrance.

Key words: iodonium salt, amines, charge transfer complexes