Perylene complexes room temperature conductivity

Recently, higher conductivities have been reported for several dithiolene complexes (5, 427, 505, 506). For example, (perylene)2[Ni(S2C2(CN)2)2] has a room temperature conductivity of 50i2 cm i with an energy of activation of 0.1 eV. These conductivites have been attributed to conduction through the organic cation and not through the dithiolene anion (5). 

The room temperature conductivity of polycrystalline samples of the naphthalene cation radical salts lies between 0.1 and 1 (Q cm) . Single crystals measured along the stack direction show a conductivity of several 100 (Q cm) depending on the quality of the crystals and to some extent on the nature of the counterions, solvent inclusion etc. The naphthalin cation radical salts can be stored for sometime at room temperature, if moisture is excluded. The corresponding radical ion complexes of perylene, pyrene, fluoranthene, and other arenes of higher number of fused rings exhibit a much greater stability and can be handled under normal laboratory conditions. 

The complex obtained by electrochemical oxidation of perylene in the presence of Ni(tcdt)2 has a 1 1 stoichiometry, PerNi(tcdt)2, and it is a semiconductor with a room temperature conductivity of 4 2 S/cm [111]. This difTerent stoichiometry is not unexpected in view of the smaller electron accepting ability of the complex in which the oxidation potential of Ni(tcdt)J (0.73 V versus SCE) is lower than that of perylene (0.91 V versus SCE) under the same conditions. This... 

The complex [perylene]2[Ni(mnt)2] showed the largest electrical conductivity among the nickel dithiolate complexes (a = 50 Q-1 cm-1 at room temperature on single crystals) but it has not yet been structurally characterized.2218,3219... 

The first report of a perylene-iodine complex with metallic conductivity was Per(l2)4 by Kao et al. [10], with values as high as 51.9 S/cm at 300 K. A broad maximum of conductivity exists at ca. 235 K (Figure 2.3). In a few samples that did not crack at lower temperatures, a gap of 0.1 eV was measured. The EPR linewidth at room temperature is 10.9 G, clearly distinguishable from the Per2(l2)3 complex. The authors indicate that spin density from EPR exhibits an activated behaviour with = 0.02 eV in the range 100-300 K, consistent with a model of a narrow band-gap semiconductor. The determination of the crystalline structure was not accomplished, but from X-ray oscillation photographs, an incommensurate structure was proposed. 

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