What Is Phenylacetylene?
Phenylacetylene is an organic compound with the molecular formula C8H6.
Phenylacetylene consists of a phenyl group bonded to an alkyne. It is also known as ethynylbenzene, phenylacetylide, phenylethyne, 1-phenylethyne, etc. Its CAS number is 536-74-3. CAS registration number is 536-74-3.
It has a molecular weight of 102.133, a melting point of -44.8°C, and a boiling point of 143°C. At room temperature, it is a colorless or pale yellow, clear, highly viscous liquid. It is extremely soluble in ethanol, acetone, and diethyl ether, but almost insoluble in water. Its density is 0.93 g/cm3.
Uses of Phenylacetylene
Phenylacetylene is mainly used as a raw material for organic synthesis. A typical example of a reaction is the formation of polyphenylacetylene through a polymerization reaction. This reaction proceeds using Rh and Pt complexes and tungsten as catalysts.
It is also used in the conversion of nitrones to alkynylhydroxylamines in the presence of trimethylaluminum. It is also often used in research as an analog of acetylene.
This is because liquid phenylacetylene is easier to handle than gaseous acetylene. Examples of organic reaction chemistry studies include the reported oxidative carbonylation of phenylacetylene in the presence of palladium catalysts.
Properties of Phenylacetylene
1. Synthesis of Phenylacetylene
Phenylacetylene can be synthesized by the reaction of β-bromostyrene with molten potassium hydroxide to remove hydrogen bromide or with sodium amide in ammonia as a base to remove hydrogen bromide from styrene dibromide.
2. Chemical Reaction of Phenylacetylene
Phenylacetylene can be partially hydrogenated using a Lindler catalyst (palladium catalyst supported on calcium carbonate). This reaction yields styrene. Phenylacetylene can also be cyclotrimerized with cobalt (II) bromide to yield 1,2,4-triphenylbenzene (97%) and 1,3,5-triphenylbenzene.
Like acetylene, phenylacetylene reacts with ammoniacal copper and silver salt solutions to form explosive metal salts.
3. Safety Control Information for Phenylacetylene
Phenylacetylene may be altered by light. It has a low flash point of 31°C. It should be stored away from high temperatures, direct sunlight, heat, sparks, and static electricity. Miscibility with strong oxidizers is considered dangerous, and carbon monoxide and carbon dioxide are listed as hazardous decomposition products.
Types of Phenylacetylene
Phenylacetylene is sold mainly as a reagent product for development and research.
The products are available in different volumes such as 25g , 25mL, 100mL, and 500mL, and are offered in volumes that are easy to handle in the laboratory. These reagent products require refrigerated storage. Phenylacetylene has a low flash point of 31°C and is designated as a hazardous material.