On the Role of Aurophilic Interactions in Determining Geometries in [Pn(AuL)₄]⁺ Complexes (Pn = N, P, as)

The nature of Au···Au interactions in poly‐gold complexes has been a fervent field of research since the term “aurophilicity” was coined by H. Schmidbaur in the late 1980s. Herein, the importance of such interactions is addressed in defining the solid‐state geometries of discreet gold–pnictonium clusters [Pn(Au·PMe 3 ) 4 ] + (Pn = N–As), using in‐depth computational methods such as energy decomposition analysis and electron localization functions. It is found that predicted geometries of simplified congeners of known tetrahedral N and square‐planar As derivatives align with those reported structures, while the as‐yet unknown square‐pyramidal geometry is predicted for P. The tetrahedral to square‐pyramidal switch arises from shorter Au···Au contacts in the latter geometry, which allows for increased metal–metal dispersion interactions, i.e., aurophilic interactions, which overcome the high electrostatic interactions predicted for the same species in the tetrahedral conformation.