Spectrophotometric and Electrochemical Study of the Complexation of Iodine with 1,10-Diaza-18-Crown-6 in Acetonitrile Solution

The complexation reaction between iodine and 1,10-Diaza-18-Crown-6 (DA18C6) has been studied in acetonitrile by spectrophotometric, biamperometric and conductometric techniques. The results are indicative of the formation of [(CH3CH)nI+.I¯3] from iodine and acetonitrile, and the formation of DA18C6 I+. I¯ from DA18C6 and [(CH3CH)nI+.I¯3]. The formation constant of the latter reaction has been calculated from the absorbance-mole ratio data, using the nonlinear least square program "KINFIT". The IR spectra of acetonitrile-acetonitrile iodine complex and DA18C6-DA18C6 iodine complex arecompared and the effect of complexation on absorption bands are discussed.