Muon studies in organic conductors

Abstract

This paper contains a brief review of muon studies of organic conductors with emphasis on polymers. The species created by implanted muons in both semiconducting polymers and polymers doped to metallic values of conductivity are described. Both diamagnetic centres and paramagnetic radicals are formed in the semiconducting materials. The mechanisms of interaction of the muon with the polymers and the longitudinal relaxation of the muon species are discussed. In highly conducting polymers the muons are primarily present in diamagnetic states. Implanted muons have also been used to study both organic chargetransfer salts and Rb 3 C 60 in the superconducting state.

Muon-Spin Rotation Studies of Electronic Properties of Molecular Conductors and Superconductors

“…Conducting polymers have attracted interest from a fundamental point of view because of the different types of mobile defects that can be found in them, including solitons and polarons. , The reaction between muonium and trans -polyacetylene − produces a diamagnetic, neutral muon defect and a highly mobile unpaired spin (a soliton, see Figure ). Because the unpaired spin is mobile, the hyperfine coupling between it and the muon defect is intermittent .…”

Synthese von gestapelten `Push-Pull'-Acetylenen

“…Von den nach Schema 3 synthetisierten Push-Pull-Acetylenen erwiesen sich die Pyrrolidin-Derivate 1a, 1b und 1c als wenig geeignet für Röntgenstruktur-Untersuchungen: Einmal lagen die Schmelzpunkte mit 308 (1a), 258 (1b) und 698 (1c) sehr tief, zudem färbten sich die Verbindungen bei Raumtemperatur rasch dunkel 10 ), und schliesslich bilden sich bei der Umkristallisation bei À 308 anstelle schöner Einkristalle Kristallkuchen. Andererseits zeichnen sich die Push-Pull-Acetylene 1e, 1f und 1g durch wesentlich höhere Schmelzpunkte aus 11 ), was Röntgenstruktur-Untersuchungen bei Raumtemperatur möglich macht, während der Morpholino-ester 1d 11 ) bei 110 K untersucht wurde.…”