Difference between benzylamine and aniline

In the chemical industry, the nuances of professional terminology often determine the performance and application of the product. Today, we will delve into the differences between two similar aromatic amines, benzylamine and aniline, to provide valuable information for chemical workers.

1. Benzoamine and Aniline

Benzoamine has the structural formula C6H5CH2NH2, where the phenyl ring is linked to a methyl group followed by an amino group. The structural formula of aniline is C6H5NH2, and the benzene ring is directly connected to the amino group. This subtle structural difference makes them significantly different in physical and chemical properties.

Figure 1: Schematic diagram of the structure of benzylamine and aniline

from the molecular structure, the presence of methyl groups makes the molecular weight of benzylamine slightly higher than that of aniline. Specifically, the molecular weight of benzylamine is 108.14, while the molecular weight of aniline is 65.12. Although this difference may seem small, it has an important impact on chemical reactivity and physical properties.

2. Benzylamine and Aniline Properties Comparison

1. Chemical nature difference

The chemical stability of benzylamine and aniline is different, which is mainly related to the substituents in their structures. The presence of the methyl group imparts better stability and lipophilicity to the benzylamine, making it less susceptible to decomposition under high temperature conditions. Aniline, on the other hand, has strong electrophilicity due to the absence of methyl groups and is prone to react with strong oxidants or strong reducing agents.

2. physical property difference

There are also significant differences in density, melting point and boiling point for benzylamine and aniline. Benzylamine has a density of 1.093g/cm³, a melting point of -77.7°C, and a boiling point of 194°C, while aniline has a density of 0.951g/cm³, a melting point of -33.5°C, and a boiling point of 160.7°C. These differences in physical properties indicate that the two require different conditions during storage and transportation.

Figure 2: melting points and boiling points of benzylamine and aniline

3. Application field differences

Benzylamine is mainly used in the manufacture of intermediates in organic synthesis, such as spices, dyes and pesticides. Its stable chemical properties make it widely used in these fields. Aniline is widely used as additives for dyes, plastics and textiles. Its hydrophilicity allows it to exhibit unique properties in these fields.

3. Benzylamine and Aniline Identification Method

1. physical identification method

In the absence of professional instruments, benzylamine and aniline can be initially identified by observing the density, color and state of the liquid. In general, the density of benzylamine is slightly higher than that of aniline, and there is no obvious difference in color.

2. Solubility test

The two substances were added to water separately and their dissolution was observed. Benzoyl amine can be fully dissolved with water, while aniline has low solubility and is partially soluble in water.

3. chemical identification method

Through the reaction with NaOH solution, benzylamine and aniline can be identified more accurately. After the benzylamine was mixed with NaOH solution, the solution was alkaline, while aniline had no obvious reaction.

4. instrumental analysis method

With the help of an infrared spectrum analyzer, the characteristic peaks of the two substances can be detected separately. A characteristic absorption peak of the NH2 group is shown in the infrared spectrum of benzylamine, whereas the position of the absorption peak differs for aniline.

4. summary

From the structure, properties, applications and identification methods, benzylamine and aniline, although the name is only one word apart, but there are significant differences in practical applications and chemical properties. When selecting and using these two substances, chemical workers must be based on specific chemical reaction conditions and application requirements to avoid product quality problems caused by confusion.

Through the detailed analysis of this paper, we hope that chemical workers can better understand and apply these two aromatic amines, and bring higher quality products for chemical production.