The reaction of phenoxatellurine with single-electron oxidizers revisited

The reaction of phenoxatellurine (PT) with the known single-electron oxidizers AlCl₃/CH₂Cl₂, [NO][SbF₆] and [NO][BF₄] provided the diamagnetic products [(PT)CH₂Cl][AlCl₄] (1), [PT₂][SbF₆]₂ (2) and [PT₃][BF₄]₂ (3), respectively, which were fully characterized by X-ray crystallography. The dications [PT₂]²⁺ and [PT₃]²⁺ present in 2 and 3 can be regarded as dimers of the elusive radical cation [PT]˙⁺ or as adduct between this dimer and neutral PT, respectively. The stacking between the aromatic layers of [PT₂]²⁺ and [PT₃]²⁺ can be best described using the pancake bonding (PB) model. The computational analysis uncovers the essential role of London dispersion effects for the stacking process and reveals the Te–Te interactions to be dominated by non-covalent bonding. The results are compared with those of the related thianthrene (TA) system.