Tellurium tetrachloride complexes

When solutions of aniline, JV-methylanilines, or amino(methyl)benzenes are mixed with solutions of tellurium tetrachloride, complexes are formed. These complexes react in refluxing methanol to yield aryl tellurium trihalides1,2 The trihalotelluro group is claimed to occupy the position para to the amino substituent2. 

Tellurium dioxide complexes with thiourea, 305 Tellurium dithiocyanate complexes, 303 Tellurium hexafluoride complexes, 303 with amines, 304 Tellurium sulfate complexes, 303 Tellurium tetrabromide complexes, 302 Tellurium tetrachloride complexes with acetamide, 304 with amines, 304 with pyridine N-oxide, 304 Tellurium tetrafluoride complexes with amines, 304 with dioxane, 304 Tellurotungstates, 1042 Tempera ture-jump studies molybdenum(VI) complexes, 1259 Terbium complexes p diketones, 1081... 

Tellurium tetrachloride, TeC. Colourless solid, m.p. 225 C, b.p. 390, obtained Te plus excess Clj. Hydrolysed by water, forms complexes including [TeClftP ions. 

The same method was employed for the synthesis of benzo[<2]phenotellurazine 42 and proven to be more efficient. The heterocycle 42 was obtained in 55% yield (89H1007). A possible explanation for the higher yield of 42 is that the transmetallation reaction in this particular case dominates the side formation of nonreactive complex of the amine with tellurium tetrachloride. There is no need for an additional step of the isomerization of the formed aryltellurim trichloride. 

A number of hexahalogenotellurates(IV) have been investigated. A few rather unstable hexafluoro complexes are known, for example the nitrosonium compounds of composition (NO)2XF6 have been obtained40 from the reaction of nitrosulfuryl fluoride, NOS02F, with selenium or tellurium tetrachloride. The selenium compound loses nitrosyl fluoride at room temperature to leave the pentafluoroselenate(lV), whereas the tellurium analogue remains... 

Although tellurium tetrachloride has been reported55 to form a 1 2 complex with acetamide, there appears to be little other information available on the complex. Similarly, the reported tributyl phosphate complex of polonium tetrachloride56 has received little attention. The formation of a polonium(IV) perchlorate complex with tributyl phosphate has been suggested57 in the solvent extraction of polonium from perchloric acid. 

Chlorophenyl Tellurium Trichloride1 A 100 ml one-necked flask is fitted with a reflux condenser carrying a calcium chloride drying tube and charged with 2.7 g (10 mmol) of tellurium tetrachloride, 3.5 g (10 mmol) of 4-chlorophenyl mercury chloride, and 30 ml of dry dioxane. The mixture is heated under reflux for 4 h, cooled to 20 , the mercury dichloride/dioxane complex is filtered off, and the filtrate is distilled under vacuum. The residue is recryslallized from glacial acetic acid yield 3.3 g (96%) m.p. 225°... 

No phenotellurazine was obtained when the reaction was carried out with dioxane as the solvent. The complex of tellurium tetrachloride with diphenylamine was not converted to phenotellurazine when refluxed in dioxane in the presence of catalytic amounts of mercury(II) acetate1. 

Tellurium tetrachloride forms yellow complexes in aqueous solution when HCl is added. Baker and Taylor [95] identified the species [TeCy and [TeCl4(OH)] in these yellow solutions. The second complex is probably monohydrated, retaining the central ion (Te" " ) its octahedral coordination. The main Raman bands of these species are located at 310 cm (polarized) in [TeCy and 289 cm [TeCWOH)] . 

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