New "molecular metals" based on symmetrically tetrasubstituted copper phthalocyanine complexes

Pure copper(II) tetrasubstituted phthalocyanine complexes, CuPTX (where X = -NO2, -NH2, -SO3H, and -OH) were synthesized. The electrical conductivity properties of these complexes were investigated both before and after iodine doping for the first time. Elemental, electronic, IR, magnetic susceptibility measurements, ESR, X-ray diffraction, and TGA analytical techniques were used to characterize and study the effect of substituents as well as iodine doping. Variation in the electrical conductivity of the copper phthalocyanine derivatives depends on the nature of the substituents and were found to show similar to 10(5) times improved electrical conductivity in comparison to parent unsubstituted copper phthalocyanine. Interestingly, these substituted complexes after iodine doping showed remarkably increased electrical conductivity nearly 10(12) times that of unsubstituted copper phthalocyanine. This may be accounted for by 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.