Synthetic conducting materials II. Partial oxidation of bis(difluoroborondimethylglyoximato)nickel(II) with iodine

Bis(difluoroborondimethylglyoximato) nickel(II), Ni(DMGB)2, has been synthesized by reaction of Ni(DMG)2 with BF3, this complex was further oxidized by iodine to form partially oxidized crystal with metallic luster. This charge-transfer salt was then characterized by elemental analysis, infrared, electronic, Raman and mass spectrometry. The composition of complex is Ni(DMGB)2I2.92. The resonance Raman spectra show two fundamental transition peaks at 178cm−1 and 180cm−1 indicate that the polyiodide exist at I2I3−1 species. This result was further evidenced by thermal analysis which show successive loss of I2 and I with negligible heat transfer. The physical state and properties of unpaired electrons in charge-transfer salts were investigated by magnetic susceptibility and electron paramagnetic resonance spectra in variable temperature condition from room temperature to 77K. The magnetic susceptibility data indicate that there is 0.2 unpaired electron per molecule. The variable temperature electrical conductivity measurement show that the conductivity of this salt is 1.57×10−3Scm−1 at room temperature with activation energy of 0.50 eV.