Spectrophotometric Study of the Interaction of Iodine Monochloride with Aza-15-crown-5 in Chloroform Solution

摘要

The complex formation between iodine monochloride and aza-15-crown-5 (A15C5) has been studied spectrophotometrically in chloroform solution at 25°C.The results prove the formation of 2:3 and 3:4 stoichiometries between A15C5:ICl.In the case of 2:3 reaction,the simultaneous formation of ICl_2~- and I2 through two chemical equilibria is confirmed.The 3:4 reaction proceeds via consumption of I2 and formation of I_3~-.Several equations are suggested for the observations.The stability constants of 2:3 and 3:4 ad-ducts were calculated by computer fitting of the absorbance-mole ratio data.The experiments were repeated at 40°C and results compared with those obtained at 25 deg C.The results indicate that the complexes are weaker at the higher temperature.The conductivity measurements are indicative of ion pairing in all cases.Finally,the solid 3:4 adduct was isolated and its IR spectrum compared with that of A15C5.