Tellurium dithiocyanate

Tellurium dithiocyanate is known only in the form of its yellow complexes with thioureas. These complexes were prepared from bis[thiourea]tellurium dihalides and potassium or ammonium thiocyanate in aqueous or methanolic media. 

Bis[ethylenethiourea]telIuriuin Dithiocyanate 2.0 g (4.1 mmol) of bis[ethylenethiourea]tellurium dibromide are added to a solution of 7.0 g (90 mmol) of anunonium thiocyanate in 20 ml of ethanol and the mixture is heated until the tellurium compound has dissolved. The red solution is cooled to allow the product to crystallize yield 0.7 g (39%) m.p. 144° (dec.). 

Bif trimethylenethiourea tellurium dithiocyanate [m.p. 214° (dec.)] was similarly prepared in 89% yield  

Bis[thiourea]tellurium Dithiocyanate 5.0 g (11.4 mmol) of bis[thiourea]tellurium dibromide are added to a stirred solution of 165 g (2.1 mol) of ammonium thiocyanate in 150 ml of water at 60-70° and the mixture is stirred at 70° until a homogeneous, red solution has formed. This mixture is filtered to remove a small quantity of precipitated tellurium, the filtrate is placed in a refrigerator overnight, and the cold mixture is filtered. The collected crystals are washed with ethanol containing a little concentrated hydrochloric acid and then with diethyl ether yield 2.7 g (60%). 

Tetrakis[thiourea]telluriiiin Dithiocyanate 3.0 g (7.6 mmol) of bis[thiourea]tellurium dithiocyanatc arc dissolved in 75 m/ of 10% aqueous thiourea solution at 40°. The solution is filtered, the filtrate is kept at 20° overnight, and the deposited crystals are collected yield 3.4 g (72%). 

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The group VIB cyanides, thiocyanates and selenocyanates and their complexes with species such as thiourea have been described.1,45 For example, the tellurium dithiocyanate complex has been prepared45 by treatment of tellurium dichloride or tellurium dibromide with ammonium thiocyanate. It seems that little information exists on the preparation of tellurocyanates and there is a sparsity of data on polonium derivatives. Indeed, the only known cyanide of polonium is probably a salt of the quadrivalent element.1... 

A single-crystal X-ray structural analysis of bis[ethylenethiourea]tellurium dithiocyanate showed the tellurium atom to be coordinated to four sulfur atoms with planar trans-arrangement of the ligands1. 

Thiocyanogen oxidizes diorgano telluriums to diorgano tellurium dithiocyanates. ... 

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 pseudohaUdes, such as the dicyanide [14453-24-8] Te(CN)2, the dithiocyanate [83543-04-8] Te(SCN)2, and thiourea complexes with Te(SCN)2, have been prepared. These are similar to the haUdes in properties. 

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