From tellurium

Tellurium and tetra-r-butyidiphosphane or tetraisopropyldiphosphane reacted to give bis[dialkylphosphano tellurium derivatives. 

Bis di-t-butylphosphano] Tellurium A solution of 18.2 g (62.8 mmol) of tetra-t-butyldiphosphane in 20 ml of toluene and 9.6 g (75.4 mmol) of tellurium are refluxed in an argon atmosphere for 3 days. The red solution is filtered to remove unreacted tellurium. The filtrate is mixed with pentane. On cooling pale yellow needles are formed yield 92% m.p. 77°. 

In a similar reaction with tetraisopropyldiphosphane some of the starting material invariably contaminates the diphosphano tellurium. Recrystallization from pentane produced the desired tellurium compound in low yield.  

---

Complete separation of selenium from tellurium caimot be achieved owing to classical Raoult s law considerations and what appears to be the... 

Tellurium nitride was first obtained by the reaction of TeBt4 with liquid ammonia more than 100 years ago. The empirical formula TeN was assigned to this yellow, highly insoluble and explosive substance. However, subsequent analytical data indicated the composition is Tc3N4 which, in contrast to 5.6a and 5.6b, would involve tetravalent tellurium. This conclusion is supported by the recent preparation and structural determination of Te6N8(TeCl4)4 from tellurium tetrachloride and tris(trimethylsilyl)amine (Eq. 5.5). The TceNs molecule (5.12), which is a dimer of Tc3N4, forms a rhombic dodecahedron in which the... 

The only structurally characterized derivative of a trisimido organophos-phonate anion is the spirocyclic tellurium(IV) complex (19), which is obtained from the interesting redox reaction between PhPCl2 and [Li2Te(N Bu)3 ] 2 [27]. The phosphorus(V)-centered ligands are generated by imide transfer from tellurium to the phosphorus(III) atoms with concomitant reduction of one-half of the tellurium in the Te(IV) reagent to elemental tellurium [27]. 

Organyltellurium trichlorides from tellurium tetrachloride and organic substrates... 

From tellurium tetrachloride and ketones and carboxylic anhydrides... 

The aryl derivatives, which are not easily accessible from tellurium tetrabromide and tetraiodide, are therefore prepared by this route. 

Cleavage of allyl carboxylates (general procedure) f To a solution of NaHTe (prepared in situ from tellurium powder (1.30 g, 1.0 mmol) and NaBH4 (0.90 g, 2.4 mmol) in EtOH (20 mL) buffered with deoxygenated HOAc (1.2 mL in 5 mL EtOH)) is added the allyl carboxylate (0.005 mol). The mixture is refluxed under N2 for 2 h, then filtered, the filtrate... 

Method B (general procedure)7 To an NaHTe solution, prepared from tellurium powder (1.27 g, 10 mmol) and NaBH4 (0.9 g, 24 mmol) in absolute EtOH (25 mL), is added the 2-haloethyl ester (10 mmol) in EtOH (5 mL). (The reaction takes place instantaneously for 2-bromoethyl esters at room temperature.) The mixture is stirred for 1 h, then acidified with dilute HCl, extracted with ether and the organic phase dried and evaporated. The residue is recrystalUzed from appropriate solvents to give pure carboxylic acids. 

A solution of o-bromophenyl ethynyl ketone (10 mmol) in DMF (20 mL) was slowly added to a stirred solulion of NaHTe (12 mmol), which was prepared from tellurium... 

Ditelluraspiro[3,4]octane F. To a cooled solution of KTeCN in DMSO (30 ml.) under nitrogen, which was generated from tellurium (1.30 g, 0.01 mol) and KCN (0.69 g, 0.011 mol), was added a solution of l,l-bis[(tosyloxy)methyl]cyclobutane E (1.50 g, 0.0035 mol). The mixture was heated overnight at 90-100°C under nitrogen and then stirred at room temperature for 1 day. The dark suspension was poured into dilute aqueous NaOH solution (100 mL, 1.5%). The precipitate was filtered, washed, dried and extracted into CH2CI2 using a Soxhlet extractor, until no more blue colour was extracted. Concentration... 

---