A new heterocycle containing tellurium and sulfur atoms, 5H, 7H-dibenzo [b, g][1, 5] tellurathiocin (1), has been synthesized. The transannular bond formation between tellurium and sulfur atoms was found in the reaction of 1 with coned H 2 SO 4 by 1 H, 13 C, and 125 Te NMR spectroscopy. Two-electron oxidation of 1 with 2 equiv. of NOPF 6 gave the tellurathia dication salt 3 (> Te+–S+< 2PF 6−) which acts as an oxidizing agent.