REDOX DISSOCIATION OF MELTED TETRAPHOSPHORUS DECASULFIDE

Abstract

P₄S₁₀ suffers a fast oxido-reductive dissociation when melted, losing one of its four terminal S atoms to yield P₄S₉, which is characterized by nmr, irand Raman spectroscopy. This dissociated state is largely retained in the cooled melts, which appear to be made up of unaltered P₄S₁₀ crystals embedded in an amorphous matrix containing the dissociation products; such melts give rise easily to supersaturated solutions in CS₂, from which crystals of pure P₄S₉—form I separate on standing.

The same holds true for commercial “P₂S₅,” for which a definite positive correlation was found between the P and P₄S₉ contents.

Examples of redox dissociation of other P/S compounds are quoted for the sake of comparison.