Sonochemical synthesis, characterization, thermal and semiconducting behavior of nano-sized azidopentaamminecobalt(III) complexes containing anion, CrO 4 2- or Cr 2 O 7 2

New nano-sized cobalt(III) coordination complexes, [Co(NH ) N ]CrO (1N) and [Co(NH ) N ]Cr O (2N) were synthesized using an innovative sonochemical methodology based on reaction between [Co(NH ) N ]Cl and potassium salt of CrO or Cr O in aqueous medium. These complexes were also compared with their respective bulks which were synthesized under identical conditions in the absence of sonicaion. All the complexes were characterized by elemental analysis and spectroscopic techniques (UV-visible and IR). Morphology and particle size of nano-sized complexes was determined by SEM and Zeta-sizer respectively. TGA was used for comparative thermal stability and XRD to identify the phase difference between nano structures and bulk complexes. Furthermore, the electrical property was investigated and all complexes were found to be electrical semiconducting materials and 2N shows better result than others. The single crystals X-ray structure study of new [Co(NH ) N ]Cr O revealed the presence of discrete ions, [Co(NH ) N ] and Cr O , crystallizes in monoclinic, space group P , with R=0.0636 in the solid state.