Spin–orbit effects on the aromaticity of the Re 3Cl 9 and Re 3Br 9 clusters

Abstract

Here, we report density functional calculations of the electronic structure and nuclear independent chemical shift (NICS) values of the Re 3Cl 9 and Re 3Br 9 clusters including scalar and spin–orbit relativistic effects (ADF + ZORA + SO). Our calculations have shown that both the clusters exhibit aromaticity and that spin–orbit effects decreases aromaticity due to the fact that the 5d 3/2 spinors are mostly occupied and are more contracted than the scalar 5d orbitals.