Stable Metallic State of a Neutral-Radical Single-Component Conductor at Ambient Pressure

Molecular
metals have been essentially obtained with tetrathiafulvalene
(TTF)-based precursors, either with multicomponent ionic materials
or, in a few instances, with single-component systems. In that respect,
gold bis­(dithiolene) complexes, in their neutral radical state, provide
a prototype platform toward such single-component conductors. Herein
we report the first single-component molecular metal under ambient
pressure derived from such Au complexes without any TTF backbone.
This complex exhibits a conductivity of 750 S·cm–1 at 300 K up to 3800 S·cm–1 at 4 K. First-principles
electronic structure calculations show that the striking stability
of the metallic state finds its origin in sizable internal electron
transfer from the SOMO-1 to the SOMO of the complex as well as in
substantial interstack and interlayer interactions.