12-Membered Macrocycles Containing Ditelluroxane and Selenotelluroxane Units

The reaction of benzeneseleninic acid with bis(p-methoxyphenyl) tellurium dihalide [halide = Cl (1), Br (2)] afforded colorless crystals in moderate yield. Single-crystal X-ray diffraction revealed the formation of 12-membered macrocycles [(p-MeO-C6H4)(2)Te(mu-O)(mu-PhSeO2)(mu(4)-X)](2) [X = Cl (1), Br (2)] where the halogen atoms, which are stabilized by Te-X interactions, cap the macrocycle on both sides. The reaction of NaI with 1 afforded the iodo-capped macrocycle [(p-MeO-C6H4) Te-2(mu-O)(mu-PhSeO2)(mu(4)-I)](2) (3) in good yield. In the solid-state structures of 1-3, the alignment of the phenyl group on Se changes with respect to the macrocycle. Macrocycle 3 shows rare Se-pi interactions, which lead to the formation of a supramolecular polymeric network. Further reaction of methaneseleninic acid with bis(p-methoxyphenyl) tellurium dichloride in methanol in the presence of triethylamine afforded a 12-membered macrocycle [(p-MeO-C6H4)(2)Te(mu-O)(mu-MeSeO2)(mu(4)-Cl)](2) (4), which is structurally similar to 1-3.