From Polytelluride Species

Tetratelluride anions were generated by cathodic reduction of tellurium at — 1.4 V in a cell consisting of a tellurium cathode and a platinum-net anode. AIM solution of dry sodium perchlorate in dimethylformamide served as the catholyte. The tetratelluride ions were then reacted with alkyl halides to yield the corresponding dialkyl ditellurium . 

Bis[dimethylpropyIsilylmethyl] Ditellurium An H-shaped electrolytic cell with a catholyte volume of 100 ml is fitted with a tellurium cathode (99.99% purity, 15-20 cm surface area) and a platinum-net anode. To the cathode compartment, separated from the anode by a ceramic diaphragm of 1.6 /rm pore size, are added 100 m/of a 1 molar solution of dry sodium perchlorate in dimethylformamide and the catholyte is deaerated with argon. At a cathode potential of 1.4 V with respect to an aqueous saturated calomel electrode, 2500 

Irgolic Organic Tellurium Compounds with one Te,C Bond 

When a,tu-dihaloalkanes were reacted with tetratelluride anions, 1,2-ditelluracycloalkanes were isolated.  

Cyclohexyl methyl ditellurium, an unsymmetrical ditellurium derivative, was claimed as the product (60% yield), when cyclohexyl bromide and methyl iodide were added in sequence to the tetratelluride solution.  

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The chemistry of polyselenides, polytellurides, and their metal complexes is very well established. Typical structures of polyselenide dianions are shown in Fig. 16.8.5. In these species, the Se-Se bond distances vary from 227 to 236 pm, and the bond angles from 103° to 110°. The tethered monocyclic structure of Se - in the complex Sr(15-C5)2(Se9) has a three-connected Se atom forming two long and one normal Se-Se bonds at 295, 247, and 231 pm (anticlockwise in Fig. 16.8.5, with the longest bond represented by a broken line). The other Se-Se bonds are in the range 227-39 pm. 

Some typical structures of polytelluride dianions, Te2-, are shown in Fig. 16.8.6. In these species, the Te-Te bond distances vary from 265 to 284 pm. In the bicyclic polytellurides Te2- and Teg-, the central Te atom each has four long bonds with bond lengths from 292 to 311 pm. 

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