Die Erorterung der elektrischen Leitfahigkeit einer breiten Palette von organischen Stoffen fust auf einem Vergleich zwischen den Stoffen, die Ladung wirkungsvoll transportieren, und denen, die dies nicht tun. Der Vergleich zeigt, das die besten Leiter Molekule enthalten, die a) bei der Abgabe oder Aufnahme eines Elektrons Radikalionen mit einem neuen aromatischen Sextett bilden, das b) aufgrund „gemischter” Wertigkeiten (mixed valence interaction) wandern kann. Die elektrischen Daten werden im Lichte der Chemie dieser Stoffe und der Bedeutung chemischer Bindungswechselwirkungen fur den Elektronentransport vorgestellt. Zahlreiche neue Beispiele werden diskutiert und Entwicklungsmoglichkeiten ausgelotet.

„Organische Metalle” – Die intermolekulare Wanderung der Aromatizität

Polymers are not usually considered in the context of electronic materials One objective of this article is to highlight the fact that collectively this class of materials exhibits a broad range of fascinating electronic properties A review is given of the present understanding of these phenomena in a field that is attracting increased experimental and theoretical attention

Polymers as electronic materials

Influence of chemical structure on the monolayer properties of polycyclic aromatic molecules

Cation-Radical Salts of Tetrathiotetracene and Tetraselenotetracene: Synthetic Aspects and Physical Properties

The latest advances in the synthesis and research into organic metals based on various heterocyclic systems are examined. The influence of the structure of the organic donor and of the size and geometry of the anions on the electrophysical properties of compounds of this series and the conditions governing the appearance of their superconductivity are discussed in relation to compounds of the class of tetrathiofulvalenes. The bibliography includes 150 references.

https://iopscience.iop.org/article/10.1070/RC1983v052n08ABEH002879/pdf

Organic Metals and Superconductors Based on Tetrathiofulvalene Derivatives

There is a large class of organic compounds which form stable radical ions at room temperature, that is they have a single electron in the highest occupied molecular orbital and carry a negative (e.g., tetracyanoquinodimethane) or a positive charge (e.g., tetracene tetrasulphide). They undergo simple one electron oxidation and reduction reactions and in the solid state these different oxidation states have high resistivities, generally > 1010 ohm cm. However, we have shown that the presence of small amounts (<1%) of other oxidation states as an impurity in an otherwise pure sample can increase the electrical conductivity by 5 or 6 orders of magnitude. The accompanying changes in the Seebeck Coefficient and activation energy for conduction arc of the order of 1 mv/°C and 0.5 ev respectively. These results are explained by assuming a hopping model of conduction and by postulating the existence of a redox equilibrium in the solid state.

G. R. Davies

Papers

Doping and Conduction in Organic Radical Ion Systems