The halogen analogs of thiolated gold nanoclusters.

Is it possible to replace all the thiolates in a thiolated gold nanocluster with halogens while still maintaining the geometry and the electronic structure? In this work, we show from density functional theory that such halogen analogs of thiolated gold nanoclusters are highly likely. Using Au(25)X(18)(-) as an example, where X = F, Cl, Br, or I replaces -SR, we find that Au(25)Cl(18)(-) demonstrates a high similarity to Au(25)(SR)(18)(-) by showing Au-Cl distances, Cl-Au-Cl angles, band gap, and frontier orbitals similar to those in Au(25)(SR)(18)(-). DFT-based global minimization also indicates the energetic preference of staple formation for the Au(25)Cl(18)(-) cluster. The similarity between Au(m)(SR)(n) and Au(m)X(n) could be exploited to make viable Au(m)X(n) clusters and to predict structures for Au(m)(SR)(n).