Synthesis, spectroscopic, ac conductivity and thermal studies on Co(III) acetylacetonate-iodine complex

A spectrophotometric study of 1:1 donor-acceptor complex, cobalt (III) acetylacetonate (donor) and iodine (sigma-acceptor) has been preformed. The equilibrium constants, (K) and the absorpitivity (epsilon) for the formation of the iodine complex have been calculated. The predicted structure of the solid triiodide charge-transfer complex reported in this study is further supported by thermal, far and mid infrared spectroscopic measurements. Electron transfer from Co (acac = 2 4-pentanedionate)(3) to iodine leads to the formation of an organic semiconductor with the formula of {[}Co(acac)(3)](2)I+.I-3(-). The kinetic parameters (nonisothermal method) for their decomposition have been evaluated by graphical methods using the equations of Freeman-Carroll (FC), Horowitz-Metzger (HM) and Coats-Redfern (CR). The ac conductivity and dielectric properties of {[}Co(acac)(3)](2)I+.I-3(-) have been measured over the frequency 50-10(6) Hz at temperature 298 K.