Isolation and molecular structures of novel organotellurium(IV) halides, oxyhalide and mixed halide.

The formation of chiral (R)-[2-(4-ethyl-2-oxazolinyl)phenyl]tellurium(IV) trihalides (trichloride (5), tribromide (6) and triiodide (7)) and (R)-[2-(4-ethyl-2-oxazolinyl)phenyl]tellurium(II) bromide (8) is described. The molecular structure of the first chiral organotellurium(IV) triiodide (7) is discussed. The most interesting feature of the structure of 5 is the observation of the shortest intramolecular TeN distance for any organotellurium(IV) trichloride. Compounds 5 and 6 do not undergo electrophilic addition reaction with olefins. Attempted addition reaction of 6 with olefin in methanol leads to the isolation of the rare partially hydrolysed tellurium(IV) halide, methyl-2-(dibromooxotellurium)benzoate (9). Novel stable mixed halide 12 was isolated from the bromination of 11. DFT calculations indicate that both the isomers 12a and 12b have similar stability.