Gold Nanowired: A Linear (Au₂₅)_<i>n</i> Polymer from Au₂₅ Molecular Clusters

Au₂₅(SR)₁₈ has provided fundamental insights into the properties of clusters protected by monolayers of thiolated ligands (SR). Because of its ultrasmall core, 1 nm, Au₂₅(SR)₁₈ displays molecular behavior. We prepared a Au₂₅ cluster capped by <i>n</i>-butanethiolates (SBu), obtained its structure by single-crystal X-ray crystallography, and studied its properties both experimentally and theoretically. Whereas in solution Au₂₅(SBu)₁₈⁰ is a paramagnetic molecule, in the crystal it becomes a linear polymer of Au₂₅ clusters connected <i>via</i> single Au–Au bonds and stabilized by proper orientation of clusters and interdigitation of ligands. At low temperature, [Au₂₅(SBu)₁₈⁰]_<i>n</i> has a nonmagnetic ground state and can be described as a one-dimensional antiferromagnetic system. These findings provide a breakthrough into the properties and possible solid-state applications of molecular gold nanowires