Exploring Nitriles and Isonitriles: Connections between Theory and Practice

Objectives

1. Understand what nitriles and isonitriles are.

2. Differentiate nitriles from isonitriles.

3. Identify properties and characteristics of nitriles and isonitriles, including the toxicity of some nitriles.

Contextualization

The organic functions nitriles and isonitriles play important roles in organic chemistry, being found in a variety of compounds used in the chemical and pharmaceutical industries. For example, acrylonitrile is a key component in the production of plastics such as ABS, while some isonitriles have antibacterial properties and are being investigated as potential therapeutic agents. Studying these substances is crucial for students aiming to pursue scientific and technological careers, as knowledge of these compounds can be applied in various fields such as drug manufacturing and synthetic materials.

Relevance of the Theme

Understanding nitriles and isonitriles is essential in the current context, as these substances are widely used in industrial and pharmaceutical processes. Mastery of this knowledge allows for the creation of new materials and medications, contributing to technological advancement and improvements in quality of life. Furthermore, awareness of the toxicity and risks associated with these substances is fundamental to ensure safety in handling and responsible disposal, positively impacting public health and the environment.

Nitriles

Nitriles are organic compounds that contain the functional group -C≡N, where a carbon atom is triple-bonded to a nitrogen atom. They are derived from carboxylic acids and can be found in a variety of industrial and pharmaceutical compounds.

• Structure: Nitriles have the functional group -C≡N.

• Origin: Derived from carboxylic acids.

• Applications: Used in the production of plastics, synthetic fibers, and as intermediates in drug synthesis.

• Properties: Can be toxic and have a characteristic odor.

• Example: Acrylonitrile, used in the production of plastics such as ABS.

Isonitriles

Isonitriles, also known as isocyanides, are organic compounds that contain the functional group -N≡C, where a nitrogen atom is triple-bonded to a carbon atom. They are known for their unpleasant odor and distinct chemical properties.

• Structure: Isonitriles have the functional group -N≡C.

• Origin: Can be synthesized from primary amines.

• Applications: Investigated for their antibacterial properties and as potential therapeutic agents.

• Properties: Highly reactive and generally toxic.

• Example: Phenylisocyanide, investigated for its biological properties.

Physical and Chemical Properties

The physical and chemical properties of nitriles and isonitriles are fundamental to understanding their behavior and applications. This includes aspects such as boiling point, solubility, reactivity, and toxicity.

• Boiling Point: Nitriles typically have higher boiling points than isonitriles.

• Solubility: Nitriles are soluble in organic solvents, while isonitriles have varied solubility.

• Reactivity: Both are reactive, but isonitriles are more prone to addition reactions due to the -N≡C functional group.

• Toxicity: Some nitriles are toxic and require careful handling, just like many isonitriles.

• Identification: Specific chemical tests can be used to identify nitriles and isonitriles.

Practical Applications

• Production of Acrylonitrile: Used in the manufacture of plastics such as ABS, which is widely used in products like toys and automotive parts.
• Synthesis of Medications: Nitriles serve as intermediates in the synthesis of several medications, including analgesics and anti-inflammatories.
• Study of Antibacterial Properties: Isonitriles are investigated for their antibacterial properties, with potential application in the development of new therapeutic agents.

Key Terms

• Nitriles: Organic compounds with the functional group -C≡N.

• Isonitriles: Organic compounds with the functional group -N≡C.

• Acrylonitrile: An important nitrile in plastic production.

• Phenylisocyanide: An example of an isonitrile with biological properties.

• Toxicity: A property of some nitriles and isonitriles that requires caution in handling.

Questions

• How can the presence of compounds like nitriles and isonitriles impact our daily lives?

• What are the challenges and solutions for dealing with the toxicity of these substances in industry?

• In what ways can knowledge about the chemical and physical properties of these organic functions be applied in creating new materials and medications?

Conclusion

To Reflect

Throughout this lesson, we explored the organic functions nitriles and isonitriles, comprehending their structures, properties, and practical applications. We reflected on the importance of these compounds in the chemical and pharmaceutical industries and how this knowledge can be applied to solve real-world problems. Through practical activities and discussions, we deepened our understanding of the toxicity and risks associated with these substances, and how to mitigate these risks in a safe and responsible manner. Mastery of this knowledge is essential for the development of new materials and medications, contributing to technological advancements and improvements in the quality of life.

Mini Challenge - Synthesis of Benzonitrile and Analysis of Properties

Consolidate your understanding of nitriles by performing the synthesis of benzonitrile and analyzing its physical and chemical properties.

• Divide into groups of 3 to 4 people.
• Add benzoic acid to a beaker and gently heat until it melts.
• Add ammonia dropwise to the beaker and continue heating until the reaction is complete, producing benzonitrile.
• Observe and record the physical properties of the synthesized benzonitrile, such as color, odor, and viscosity.
• Perform simple tests to identify chemical properties, such as solubility in water and reactivity with acids and bases.
• Discuss the observations in the group and present your conclusions to the class.