Polymeric Sulfur, Selenium and Tellurium

All three heavy chalcogens form polymers with an infinite helical chain structure however, the conditions under which they are produced differ 

Homogeneous crystalline alloys of selenium and tellurium, Se Tei-x, of various compositions (x = 0.1-0.9) are prepared by the co-reduction of solutions of Se(IV) and Te(IV) compounds, e.g. dialkylselenites and tetraalk-oxytelluranes (or glycol solutions of Se02 and Te02), with hydrazine.  

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