Yellow phosphorus sources

Yellow phosphorus is a highly toxic element that is still used as a rodenticide. Poultry and wild birds can be intoxicated by consumption of bait intended for rodents. Firework fragments also are a common source of poisoning in free-ranging birds. Affected birds are depressed and anorectic, have increased water consumption, and manifest diarrhea, ataxia, paralysis, coma, and death. 

Sources. Because of its reactivity and the hazards associated with its handling, yellow phosphorus is rarely used as a rodenticide. When it is used, it is concealed in butter or some other type of oil-based bait. 

Phosphorus has many allotropes. The most common of these is white phosphorus, which exists in two modifications, a-P4 (cubic) and p-P4 (hexagonal). Condensation of phosphorus from the gas or liquid phases (both of which contain tetrahedral P4 molecules) gives primarily the a form, which slowly converts to the P form at temperatures above —76.9°C. During slow air oxidation, a-P4 emits a yellow-green light, an example of phosphorescence that has been known since antiquity (and is the source of the name of this element) to slow such oxidation, white phosphorus is commonly stored under water. White phosphorus was once used in matches however, its extremely high toxicity has led to its replacement by other materials, especially P4S3 and red phosphorus, which are much less toxic. 

Phenyldichlorophosphine (2) is prepared by gradually heating a mixture of benzene, phosphorus trichloride, and aluminum chloride until a yellow solution of the complex (1) results (2 hrs.) and then refluxing for 1 hr. The heat source is... 

White elemental phosphorus consists of tetrahedral P4 molecules and is an important source of phosphorus for synthesis. In contrast, tetrahedral AS4 (yellow arsenic) is unstable, and decomposes to a grey As allotrope with a sheet structure. However, ASP3, previously only observed at high temperature in the gas phase, has been isolated at ambient temperature as a white solid, where an As atom replaces one vertex of the tetrahedron. 

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