What Is Silene?
Silene is a clear, colorless to pale yellow liquid with a ketonic odor at room temperature. Its chemical formula is C6H8O3, molecular weight is 128.13, and its CAS number is 53716-82-8. Other names for silene include (1R)-7,8-dioxabicyclo[3.2.1]octan-2-one (IUPAC name) and dihydrolevoglucosenone
They are bio-based bipolar solvents, safe for final disposal, and decompose to CO2 and H2O. It is a non-protic solvent that can be used as an alternative to conventional solvents, which are feared for their environmental impact.
Uses of Silene
Silene is used as a renewable building block for the production of valuable chemicals such as pharmaceuticals, fragrances, and specialty polymers. It can also be used in chiral pool synthesis because it is produced as a single mirror-image isomer. For example, oxidation with a peroxyacetic acid such as peroxyacetic acid yields the optically pure 5-hydroxymethyldihydrofuranone from which the HIV drug zalcitabine is available.
Silene is considered a green alternative to dimethylformamide (DMF), one of the most common organic solvents. Several standard reactions in synthetic organic chemistry, such as the production of urea, have been shown to be possible in silene solvents.
It is also useful for dispersing graphene solutions, as it has optimum polarity and high viscosity, yielding larger, less defective graphene flakes.
Characteristics of Silene
Silene has a melting point of -18°C, a boiling point of 227°C, a density of 1.25 g/cm3, and is miscible with water and many organic solvents. The kinematic viscosity of silene is 14.5 cP, which is higher than the 0.92 cP of dimethylformamide and the 1.67 cP of N-methyl-2-pyrrolidone. Silene is stable at temperatures up to 195°C and to weak acids and bases.
Other Information on Silene
1. Silene Manufacturing Process
Silene can be synthesized by heterogeneous palladium-catalyzed hydrogenation of the unsaturated ketone levoglucosenone (LGO) under mild conditions. Levoglucosenone is a building block obtained by acid-catalyzed pyrolysis of lignocellulosic biomass such as sawdust and is known as one of the sustainable materials that can be produced from renewable resources.
(C6H10O5)n → nC6H10O5 (Levoglucosan)
C6H10O5 → C6H6O3 (LGO) + 2H2O
2. Handling and Storage Precautions
Precautions for handling and storage are as follows
- Keep container tightly closed and store in a cool, dark place out of direct sunlight.
- Keep away from flames and high temperatures, as the product may react with air at high heat to form explosive mixtures or catch fire.
- Take special care to avoid contact with the eyes because of strong eye irritation.
- Avoid breathing fumes and vapors.
- Strong oxidizers, strong reducing agents, and strong acids are hazardous incompatible materials.
- Use only outdoors or in well-ventilated areas.
- Wear protective gloves, protective glasses, protective clothing, and protective masks when using.
- Wash hands thoroughly after handling.
- In case of skin contact, wash with soap and water.
- In case of eye contact, rinse cautiously with water for several minutes.