Characterization and Thermal Decomposition of Sub-allotrope Violet Phosphorus-21

Phosphorus, one of many elements that fall under the umbrella of inorganic chemistry, is currently experiencing a renaissance due to advancements in synthetic methodology. Currently, there are 4 primary allotropes of phosphorus. While red, white, and black phosphorus have been well-studied, it is only recently that a reliable synthesis of crystalline violet phosphorus has been established. Violet phosphorus, originally known as Hittorf’s phosphorus, can be further divided into sub allotropes: violet phosphorus-21 (VP₂₁) and violet phosphorus-11 (VP₁₁). To experimentally differentiate these sub-allotropes, we have developed a systematic method of characterization. We have also studied the electronic properties of VP₂₁ through a series of in situ heating experiments. Further, we have critically evaluated the effect of varying synthetic conditions on the production of crystalline VP₂₁.