Properties and Uses of Mesitylene-
Chemical and Physical Properties
Mesitylene, also known as 1,3,5-trimethylbenzene, is an organic compound with the molecular formula C9H12. It is a colorless liquid that is weakly aromatic with a characteristic odor. Mesitylene is insoluble in water but soluble in organic solvents like acetone, benzene, and chloroform. It has a boiling point of 165°C and melting point of -49°C. Chemically, mesitylene contains three methyl substituents bonded at the 1,3,5-positions of a benzene ring. This molecular structure gives it increased stability compared to toluene or xylene due to increased methylation. However, it is still classified as an aromatic hydrocarbon due to the presence of the benzene ring which allows for continuous conjugation of π-electrons.
Production and Applications
Industrially, mesitylene is produced during the catalytic reforming of petroleum naphthas or by distilling crude oil at elevated temperatures. It naturally occurs in coal tar and is also found in the essential oils of some plants. Commercially, one of the major uses of mesitylene is in the manufacture of specialty chemicals and performance materials. Due to its increased solubility in non-polar solvents compared to benzene, mesitylene serves as a replacement feedstock. It is employed in the production of fragrances, plastics, polyester resins, pesticides, and specialty solvents. Mesitylene is also a starting material in the synthesis of various pharmaceutical intermediates and fine chemicals. Some specific derivatives include isopropylbenzene, mesitol, and 1,3,5-trimethylbenzene.
Toxicological Profile
Like other alkylbenzenes, mesitylene is considered to have moderate acute toxicity if inhaled, swallowed, or absorbed through the skin. The median lethal dose (LD50) in rats is around 3 grams per kilogram of body weight for oral exposure. Symptoms of mesitylene poisoning may include irritation of mucous membranes, dizziness, nausea, vomiting, and breathing difficulties. Prolonged or high level exposures could potentially damage the liver, kidneys, and central nervous system in humans. Mesitylene is classified as a volatile organic compound (VOC) and may have negative environmental impacts if released untreated. The National Institute for Occupational Safety and Health (NIOSH) recommends an exposure limit of 125 ppm over an 8-hour workday for occupational settings. Due to its hazardous properties, mesitylene must be handled carefully with protective equipment and stored in properly ventilated areas away from heat and ignition sources.
Analytical Methods
Various analytical techniques can be employed to qualitatively and quantitatively analyze mesitylene in industrial samples and environmental matrices. Gas chromatography coupled with mass spectrometry (GC-MS) or flame ionization detection (FID) provides an accurate and sensitive means of identification and quantification down to part-per-million levels. Nuclear magnetic resonance (NMR) spectroscopy using proton or carbon-13 isotopes can be used to unambiguously characterize the unique structural properties of mesitylene. Distillation followed by infrared spectroscopy of the isolated fractions is another qualitative identification method based on infrared fingerprinting of functional groups. For workplace and ambient air monitoring, diffusive sampling tubes coupled with GC analysis are commonly utilized. These fit-for-purpose analytical protocols allow for comprehensive environmental and safety monitoring programs involving mesitylene.
The physical and chemical characteristics of mesitylene are highly valuable for its roles in industrial organic synthesis and specialty material formulation. However, sufficient precautions must still be followed due to potential acute and chronic health hazards upon exposure. Standard operating procedures, personal protective equipment, and confinement/ventilation engineering controls can help minimize risks to workers and the surrounding environment. Proper identification, handling, storage, transport, and disposal practices in compliance with applicable regulations further promote the safe production and use of this important alkylbenzene derivative. Overall understanding of its unique properties, synthesis routes, applications, toxicity profile, and analytical methods provides important context for its roles both industrially and scientifically.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
