Tellurium Dithiolates

Attempts to transesterify diorgano tellurium dialkoxides with 1,2-ethanedithiol or 1,3-propanedithiol caused formation of disulfides and reduction of the diorgano tellurium dialkoxides to the corresponding diorgano tellurium compounds.  

The reaction of diaryl tellurium oxides with 2-(4 -benzoyl-3 -hydroxy-T-phenyloxy)-eth-oxycarbonylmethanethiol in refluxing toluene with azeotropic removal of water produced diaryl tellurium dithiolates as viscous, brown oils.  

Diorgano tellurium bis[dithiocarbamates] are formed in metathetical reactions between diorganyl tellurium dihalides and sodium or ammonium dithiocarbamates.  

1- Bis[morpholino-thiocarbonyl-thio]-l-teUuracyclopentane 3.6 g (20 mmol) of ammonium morpholine-Af-carbodithioate are suspended in 10 m/ of acetone and a solution of 4.5 g (10 mmol) of 1-telluracyclopentane 

1- diiodide in 20 ml of acetone is slowly added with stirring at 20 . The mixture is stirred for 2 h at 20°, filtered, and the solvent is evaporated from the filtrate to give the yellow, crystalline product yield 3.9 g (76%) m.p. 109°. 

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The first representative of the 1,2-ditelluroles, 3,4,5,6,7,8-hexachloro-naphtho[l,8-ct/] 1,2-ditellurole 37, was obtained in low yield by heating octachloronaphthalene with elemental tellurium at 350°C (73USP3769276) by analogy with the method developed for the synthesis of congeneric 1,2-dithiole and 1,2-diselenole derivatives (72T963). 

There are single examples of sulfur and selenium xanthates with the remaining structures to be described in this section featuring tellurium as the central element. There are a significant number of binary xanthates and, in common with these, their organotellurium xanthates feature extensive supra-molecular association, usually, but not exclusively, via Te- S secondary bond interactions. A rare example of mixed-ligand 1,1-dithiolate structure is available where the odd dithiolate ligand is a dithiocarbamate. 

The 1,3-ditelluretane 88 is obtained as a minor product along with the 1,3-ditellurafulvene 89 by the reaction of phenylacetylide with tellurium followed by acidification with trifluoroacetic acid (Scheme 27) <2003TL2397>. In the reaction of trimethylsilylethynyl tellurolate, use of tifluoroacetic acid in /-butyl alcohol at — 20°C leads to the formation of the 1,3-ditelluretane 90, presumably via the telluraketene 91. Vilsmeier-Haack reaction on the crude ditelluretane 90 furnishes dialdehydes 27 and 92 in 10% yield. 1,3-Ditelluretanes 27 and 92 can be transformed into other derivatives, as shown in Scheme 28. An /. // mixture of 27 and 92 condenses smoothly with phosphorane to give diester product 93. The reaction with diesterdithiole phosphonate or dithiole phosphonate affords 1,3-ditelluretane derivative 94 or 95, respectively. 

Sodium tellurapentathionate reacted with two molar equivalents of potassium dithiolates in aqueous methanol to produce anionic tellurium compounds with two dithiolate groups in the molecule. The compounds were isolated as the tetraphenylarsonium salts3,4. 

Tellurium dichloride and ferrocene-l,l -dithiol condensed in benzene in the presence of triethylamine to form (1 J -ferrocenediyldilhio) tellurium1,. 

Under similar conditions, organothio tellurium compounds prepared from dithiols initially form cyclic disulfanes that may subsequently polymerize1. 

Tellurium tetrathiolates were claimed to be formed from tellurium tetrachloride and stoichiometric amounts of thiols and dithiols at low temperature with ethanol as the reaction medium1. A reinvestigation of these reactions2 showed that tellurium tetrathiolates could not be isolated under these conditions. The products were mixtures of bis[organothio] tellurium and diorgano disulfides (see p. 38). 

Diorgano tellurium diethoxides and dithiols produced diorgano telluriums and disulfides1. OC2H5... 

A number of metal 1,2-dithiolenes, mainly corresponding to 1,3-dithioles of Class 0 (Table l),and selenium-, tellurium-, etc- anaIogs,have been described in refs [10]-[12] and refs therein. Recent work has been described in refs [48], [52], [54]. In this section we describe methods of preparation and properties of cation-rich salts of some metal 1,2-dithiolenes and selenium analogs, having ligands with additional heteroatoms (S,Se,N) to an additional ring or chain. These are compounds of the following formulas, ( QII)-(XXII),... 

Ditellurimn analogs of phosphor-1,1-dithiolates and arseno-l,l-dithiolates are almost unknown. The only ditellurophosphinates reported are the hthium salts Li[R2PTe2] with R = Ph, cyclohexyl, obtained from R2PH with RLi followed by treatment with elemental tellurium in but telluroiminophosphinates,... 

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