with a planar P 6 E 6 (E = S, Se) framework in which dichalcogenido (-E-E-) groups are linked by perpendicular 20 P V 2 N 2 rings. 5 The synthesis of these polychalcogen macrocycles involves the two-electron oxidation of the dianions 1a and 1b with I 2. We now report a detailed investigation of the oxidation of the tellurium analogue 1c that provides important insights into the initial oxidation process, as well as a notable difference in the 25 final outcome of the oxidation compared to that observed for 1a and 1b. Specifically, we have identified and structurally characterised (a) the dianionic ditelluride [Te(, with an unusual planar conformation, as the product of one-electron oxidation of 1c and (b) the cyclicas the result of further oxidation. DFT calculations were carried out in order to determine the reason(s) for the unusual planarity of the PTeTeP unit in the ditelluride 2.The oxidation of the dianion 1c (as its dilithium derivative)with a one-half molar equivalent of I 2 led to the isolation of extremely sensitive black crystals, which were identified by Xray crystallography as [Li(tmeda)] 2 2 (Eq. 1). 7 As depicted in Fig. 1 heteroatom-tellurium interactions and (TpsiTe) 2 for which the antiperiplanar conformation is imposed by the bulky substituents. 10 The Te1···Te2' distance in [Li(tmeda)] 2 2 (3.884 Å) is shorter than the sum of van der Waals radii for Te (4.12 Å).13 Moreover, the closely related neutral ditelluride 60 [( t BuNH)P(μ-N t Bu) 2 P(N t Bu)Te] 2 (4), which has a similar steric environment for the Te-Te linkage, exhibits a dihedral angle of −123.8° and a Te-Te bond length of 2.7204(9) Å (Fig. S1).14 In view of these observations, DFT calculations were carried out to probe whether the conformation of [Li(tmeda)] 2 2 is stabilized by 65 intramolecular Te1···Te2' secondary bonding interactions (3.884 Å). Satisfactory structures were obtained from geometry optimizations (PBE-D3, TZP, ZORA) for planar and synclinal models of [Li(tmeda)] 2 2 and 4 simplified using Me groups in lieu of t Bu. In both instances the planar conformations were higher in 70 energy, by 8 and 37 kJ mol -1 for the models of [Li(tmeda)] 2 2 and 4, respectively. Preferred P-Te-Te-P torsion angles are 98° for the former and 90° for the latter. The small difference of energy suggests that the conformation observed in the crystal structure of [Li(tmeda)] 2 2 is imposed by packing forces. Further analysis on 75 the electronic structures of the [Li(tmeda)] 2 2 models failed to identify a particular orbital interaction or contribution from dispersion that would help stabilize the antiperiplanar geometry.