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.

The crystal structure of the title compound, C9H12ClNTe, contains isolated mol­ecules with no close Te⋯Cl inter­molecular contacts and has the same composition as a previously published structure [Engman et al. (2004 ▶). Phospho­rus Sulfur Silicon Relat. Elem. 179, 285–292]. However, in this case, the compound has crystallized in a centrosymmetric space group, unlike the previously published structure which contained enanti­omerically pure chiral mol­ecules. In all other aspects, the metrical parameters are similar. The mol­ecules with a T-shaped coordination environment about the Te atom are linked into dimers by C—H⋯Cl inter­actions.

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The synthesis and the first X-ray structural characterization of a selenenyl selenocyanate, [o-(2,6-diisopropylphenyliminomethinyl)phenyl]selenenyl selenocyanate (), with a stable Se-Se bond are described. The isolation of stable , both in the solid state and in solution, is facilitated by strong intramolecular SeN interaction. The compound , an example of unsymmetrical diselenide, did not exhibit any glutathione peroxidase-like activity. The reaction of with thiophenol afforded (3H-benzo[c][1,2]diselenol-3-yl)(phenyl)sulfane.

The title compound, C9H13Br2ClNTe, was synthesized by reacting [2-(dimethyl­amino­meth­yl)phen­yl]tellurium(II) chlor­ide with Br2. As a consequence, the Cl and Br atoms are not well ordered but distributed over the three possible positions such that the overall stiochiometry is two Br atoms and one Cl atom. The scrambling of the Br and Cl atoms indicates a small energy barrier for the exchange process between the apical and equatorial positions. Overall, the Te atom geometry is slightly distorted square pyramidal (τ = 0.052 for the major component). However, there is a weak secondary inter­action between the Te atoms and the disordered Br/Cl atoms of a nearby mol­ecule. The Te—Br and Te—Cl distances in both disorder components fall into two groups; a longer distance for the Br/Cl involved in this secondary inter­action [2.6945 (17) Å for Br and 2.601 (9)Å for Cl] and shorter bond distances to the remaining halogen atoms, indicating that this inter­action has slightly weakened the Te—X bond, as is the case in the previously reported tribromido structure [Singh et al. (1990). J. Chem. Soc. Dalton Trans. pp. 907–913]. Otherwise, the metrical parameters in the two structures are not significantly different. An intermolecular C—H⋯Br interaction occurs.