Hydrogen-Bonding Interactions in a Single-Component Molecular Conductor: a Hydroxyethyl-Substituted Radical Gold Dithiolene Complex

The
anionic hydroxyethyl-substituted gold dithiolene complex [NEt4]­[Au­(EtOH-thiazdt)2] is synthesized and further
oxidized to the neutral radical species [Au­(EtOH-thiazdt)2]• through electrocrystallization. Single-crystal
X-ray diffraction studies highlight the existence of the two cis and
trans isomers for the monoanionic complex, with involvement of the
hydroxy group in intermolecular O–H···S hydrogen-bonding
interactions. The neutral radical complex, [Au­(EtOH-thiazdt)2]•, is isostructural with its known ethyl analogue,
namely, [Au­(Et-thiazdt)2]•. It exhibits
a semiconducting behavior (σRT = 0.05–0.07
S cm–1) at room temperature and ambient pressure
with an activation energy of 0.14 eV. Comparison of the crystal structures
and transport and magnetic properties with those of the prototypical
[Au­(Et-thiazdt)2]• single-component conductor
shows that the replacement of ethyl by a slightly bulkier hydroxyethyl
substituent affects only weakly the overlap interactions, complemented
here by added O–H···S hydrogen-bonding interactions.