Organic Semiconductors with High Conductivity. I. Complexes between Polycyclic Aromatic Hydrocarbons and Halogens

Abstract

It was found that most polycyclic aromatic hydrocarbons form molecular complexes with bromine or iodine. Those complexes which are black behave as typical semiconductors with energy gaps for conductivity of 0.1–0.2 eV., as well as with low electrical resistivity ranging from 10° to 103 ohm-cm. The complexes are unstable and a substitution reaction of halogen takes place; when this is not the case, e. g. the violanthrene-iodine complex, and the complex itself is quite stable, so also is the electrical property. It is concluded that the origin of the high conductivity is due to the interaction between hydrocarbon molecules and halogen molecules, and this is presumably due to the overlapping of molecular orbitals stretching throughout the crystal.

Conductivity and Thermoelectric Potential Measurements on Perylene:Metal Halide Complexes

“…The unexpectedly high electrical conductivity shown by the complexes formed by the reaction of polycyclic hydrocarbons with halogens was first reported in 1956 by Akamatu (1). The properties of one of the most interesting members of this group, perylene:iodine, were reported by Labes (2), Kommandeur (3), and Uchida and Akamatu (4) who found that the electrical conductivity of the molecular complex was at least 10-12 orders of magnitude higher than the constituent compounds.…”

Organic Semiconductor : A Drastic change in Electronics

“…This finding helps to show that an OC could carry current. Akamatu et al, [15] discovered that an aromatic hydrocarbon become conductive, when blended it with molecular iodine due to the formation of a charge transfer complex compound. It helps to show that the crucial parameter for controlling the conductivity is the work function of the electrode.…”

Comparison Between the Electric Conductivity of Polyhydroxamic Acids of Different Origin

“…After acidi®cation of the mixture to pH 1±3 with 3 N HCl, the polymer was separated by ®ltration. Two fractions of the Compound Activation energy a PHA from PAA Fe(COO) 2 , Cu 2 Cl 2 , and Co(CH 3 COO) 2 (1) 21.3 kcal PHA from PMAA 0.5 mmol FeCl 3 (2) 21.5 kcal PHA from PMAA 1 mmol FeCl 3 (3) 7.14 kcal PHA from a copolymer of AA and MMA (4) 113 kcal PHA from a copolymer of AA and MMA 1 mmol FeCl 3 (5) 10 Preparation of a copolymer of acrylamide and methylmethacrylate 45 g of acrylamide and 5 g of methylmethacrylate were mixed in a round-bottomed¯ask. The contents of the¯asks were dissolved in 100±200 ml of water, and 3 g of potassium persulfate were added.…”

“…Eley and Par®tt [1,2] have shown that some chelated compounds like phthalocyanin and copper-phthalocyanin have semiconducting properties. Organic compounds with paramagnetic properties are found among simple organic molecules [3,4], proteins [5] dyes [6] and chelated compounds as well as polymers [7]. Wang, et al [8] have prepared blends of conducting polymers (polythiophene and polypyrrole in insulating host polymers like polystyrene and polycarbonate resins).…”