“Synthetic metals” based on nickel(II) 2,9,16,23-tetrahalo-substituted phthalocyanine derivatives

Symmetrically nickel(II) 2,9,16,23-tetrahalo-substituted phthalocyanine complexes, NiPTX (where X=–F, –Cl, –Br, and –I) are prepared in pure state. Elemental, electronic, IR, magnetic susceptibility measurements, X-ray diffraction and TGA studies are carried out on the above complexes both before and after iodine doping. Electrical conductivity of the nickel phthalocyanine derivatives depends on the nature of the substituent and found to show ∼103 times improved conductivity in comparison to parent nickel phthalocyanine complex. It is interesting to note that substitution and iodine doping showed remarkably high ∼109 times increased electrical conductivity in comparison to nickel phthalocyanine. This may be due to the decrease in the metal–metal bond distance, increase in the approach of the ideal eclipsed system or due to the combined effects of the above factors.