Superconductors | Nature Chemistry

News & Views | 23 June 2017

Synthesis successes

Disentangling the chemistry and physics behind reported unconventional superconductivity and exotic magnetism in alkali-intercalated PAHs has remained problematic due to the lack of phase-pure samples. Two synthetic pathways have now remedied this issue, facilitating studies of cooperative electronic properties based on carbon π-electrons.

Roser Valentí
& Stephen M. Winter

Article | 24 April 2017

Redox-controlled potassium intercalation into two polyaromatic hydrocarbon solids

Reports of superconductivity in K_xPicene spurred interest in alkali-intercalated polyaromatic hydrocarbon (PAH) compounds, but their compositions and structures have remained unclear. Now crystalline K₂Pentacene and K₂Picene — neither of which are superconducting — have been prepared by mild synthesis. Structural analysis shows that the cation sites arise within the molecular layers from reorientation of the PAHs within a herringbone packing.

F. Denis Romero
, M. J. Pitcher
& M. J. Rosseinsky

Article | 24 April 2017

π-electron S = ½ quantum spin-liquid state in an ionic polyaromatic hydrocarbon

Cooperative electronic properties that arise purely from carbon π-electrons can lead to unconventional superconductivity and quantum magnetism. New packing architectures have now been established in two caesium-intercalated polyaromatic hydrocarbons, CsPhenanthrene and Cs₂Phenanthrene, both strongly correlated multi-orbital Mott insulators. The frustrated magnetic topology in CsPhenanthrene also renders it a spin-½ quantum spin liquid candidate.