Abstract

The results of this Letter reveals that the [Re 3(μ-Cl) 3Cl 9] 3-, [Re 3(μ-Br) 3Br 9] 3-, [Re 3(μ-I) 3I 9] 3- clusters exhibit aromaticity and that spin-orbit effect decreases the aromaticity due to the fact that the 5d 3/2 spinors are more contracted than the scalar 5d orbitals. The [Re 3(μ-I) 3I 9] 3- and [Re 3(μ-Br) 3Br 9] 3- clusters are the most aromatic clusters. This can be explained by the np 1/2 and np 3/2 spinors radial expectation (〈r〉) values which follows the Cl < Br < I sequence. Thus, the most extended spinors correspond to I and Br ligands, as indicated in the ELF plots. Furthermore we carried out TDDFT calculations which agrees with the fact that [Re 3(μ-I) 3I 9] 3- should show the highest value of aromaticity. © 2012 Elsevier B.V. All rights reserved.