2/1 COMPLEXES OF ANILINES WITH TELLURIUM TETRACHLORIDE - SYNTHESIS OF AMINO-SUBSTITUTED DIPHENYL TELLURIDES

Complexes (2:1) Prepared from anilines and tellurium tetrachloride were studied by H-1, C-13, Te-125, and N-15 NMR spectroscopy and submitted to chemical degradation. It was found that N- and ortho-substituted anilines generally formed 2:1 complexes where a tellurium substituent was introduced para to the amine substituent (type I complexes). On reduction, these materials afforded mixtures of 4-amino-substituted diphenyl tellurides and diphenyl ditellurides which were readily converted to 4-amino-substituted diphenyl tellurides by Cu- or Pd-induced detelluration of the ditelluride component. Other anilines formed 2:1 complexes of the coordination type (type II complexes). In these materials, the anilines served as ligands to the electron-deficient tellurium atom. On reduction, the type II complexes afforded elemental tellurium and the corresponding anilines. When dissolved in dimethyl sulfoxide, both types of complexes were chemically modified. According to spectroscopic data, the anilines of the type II complexes were readily displaced by solvent molecules to form the corresponding DMSO complex. Type I complexes seemed to produce a mixture of compounds in rapid equilibrium with each other via proton and/or ligand exchange.