Turkish Journal of Chemistry, Vol.22, No.1, 13-22, 1998
Intrinsic semiconducting materials on phthalocyanine basis
Stacked transition metal macrocycles [MacM(L)](n) with M e.g. Fe, Ru, Os, Co, Rh and Mac = phthalocyanine (Pc) 1,2- or 2,3-naphthalocyanine (1,2-, 2,3-Nc) were synthesized. The bridging ligands (L) may be e.g. pyrazine (pyz) or s-tetrazine (tz). In general, these complexes [MacM(L)](n) are insoluble in organic solvents; however, soluble oligomers [R-4 PcM(L)](n) can be prepared using metallomacrocycles RnPcM, R = t-bu, et, OR, M = Fe, Ru, which are substituted in the peripheric positions. A systematic investigation of the influence of the bridging ligands on the semiconducting properties in [MacM(L)](n) reveals that changing L, e.g., from dabco over pyz to tz leads to a steady increase of the semiconducting properties without external oxidative doping. Powder conductivities in the order of 0.1 S/cm can be reached by using s-tetrazine, 3,6-dimethyl-s-tetrazine (me(2)tz) and others, e.g. fumarodinitrile, as the bridging ligands. The intrinsic conductivities are a result of the low oxidation potential of tz and me(2)tz and due to the low lying LUMO in the corresponding bridged systems [MacM(tz)](n).
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