Observation of Te···p and X···X Bonding in para-Substituted Diphenyltellurium Dihalides, (p-Me2NC6H4)(p-YC6H4)TeX2 (X = Cl, Br, I; Y = H, EtO, Me2N)*

The supramolecular association of the previously described para-dimethylaminophenyl-substituted diorganotellurium dihalides (p-Me2NC6H4)2TeX2 (X = Cl (1), Br (2), I (3)) and (p-Me2NC6H4)RTeCl2 (R = Ph (4), p-EtOC6H4 (5)), was investigated by X-ray crystallography. Unlike almost all other structurally characterized diorganotellurium dihalides, (p-Me2NC6H4)2TeX2 (X = Cl (1), Br (2), I (3)) reveal no secondary Te···X interactions, but X···X interactions. The structure of (p-Me2NC6H4)PhTeCl2 (4) resembles that of Ph2TeCl2 and shows one secondary Te···Cl contact, whereas (p-Me2NC6H4)(p-EtOC6H4)TeCl2 (5) exhibits neither secondary Te···Cl nor Cl···Cl interactions. The unusual structural characteristics of 1–5 are attributed to the occurrence of intermolecular Te···p and p···p contacts associated with quinoid p-electron delocalization across the para-dimethylaminophenyl (1–5) and para-ethoxyphenyl (5) groups.