Detecting weak interactions between Au- and gas molecules: a photoelectron spectroscopic and ab initio study.

We show that anion photoelectron spectroscopy can be a very sensitive probe for weak intermolecular interactions between gold anion and a noble-gas atom or other nonreactive molecule. High-level ab initio calculations support the measured trend of relatively weak intermolecular interactions among various gold anion-atom complexes. The interaction between Au(-) and H(2)O is much stronger, comparable to a strong hydrogen bond. The interaction between Au(-) and O(2) is weaker than that between Au(-) and a noble-gas atom (Ar, Kr, or Xe).