Difference Between Quaternary Ammonium and Ammonia

Thekey differencebetween quaternary ammonium and ammonia is thatquaternary ammonia molecule has a central氮atom绑定到四alkyl groupswhereas ammonia molecule contains one nitrogen centre bound to threehydrogen atoms.

季铵阳离子that is derived from a normal ammonia molecule. Here, the three hydrogen atoms of the ammonia molecule are substituted with similar or different alkyl groups, and there is an extra alkyl group bound to the nitrogen atom via its lone electron pair.

CONTENTS

1.Overview and Key Difference
2.什么是第四纪铵
3.What is Ammonia
4.Side by Side Comparison – Quaternary Ammonium vs Ammonia in Tabular Form
5.概括

什么是第四纪铵?

季铵阳离子derived from ammonia molecule, and it has a central nitrogen atom with four alkyl groups substituted to it. Therefore, the chemical formula of this molecule can be written as [N-R₁R₂R₃R₄]⁺. The chemical structure of this cation is as follows:

These cations are abbreviated as quats. They are positively charged polyatomic ions. There are several ions formed by ammonia molecule including primary, secondary and tertiary ammonia. These are named according to the number of alkyl groups bound to the nitrogen atom.

The most common compounds of quaternary ammonium are quaternary ammonium salts. These compounds can be prepared by alkylation of tertiary amines in the presence of halocarbons. Generally, quaternary ammonium cations are unreactive towards even strong oxidants, strong acids, and electrophiles. However, these cations undergo degradation in the presence of exceptionally strong bases.

What is Ammonia?

Ammonia is an inorganic compound having the chemical formula NH₃. It is a gaseous substance, and it is the simplest pnictogen hydride. Ammonia occurs as a colourless gas having a pungent, irritating odour. The IUPAC name of Ammonia is azane.

化学公式为NH3。因此，摩尔质量为17.03 g/mol。氨的熔点为-77.73°C，沸点为-33.34°C。

When considering the occurrence of ammonia gas, it naturally occurs in the environment but in trace amounts as a product of nitrogenous animal and vegetable matter. Sometimes, we can find ammonia in rainwater as well. Inside our body, kidneys secrete ammonia to neutralize excess acid.

In the chemical structure of the ammonia molecule, it has a nitrogen atom bound to three hydrogen atoms. Since there are five electrons in the outermost electron shell of nitrogen, there is a lone electron pair on the nitrogen atom of the ammonia molecule. Hence, the geometry of the ammonia molecule is trigonal pyramidal. Furthermore, we can liquefy this compound easily. This is because it is capable of forminghydrogen bondsbetween ammonia molecules since there are N-H bonds and lone electron pairs as well.

What is the Difference Between Quaternary Ammonium and Ammonia?

季铵阳离子derived from an ammonia molecule. The key difference between quaternary ammonium and ammonia is that quaternary ammonia molecule has a central nitrogen atom bound with four alkyl groups whereas ammonia molecule contains one nitrogen centre bound to three hydrogen atoms.

The following table summarizes the difference between quaternary ammonium and ammonia.

概括– Quaternary Ammonium vs Ammonia

季铵阳离子derived from an ammonia molecule. The key difference between quaternary ammonium and ammonia is that quaternary ammonia molecule has a central nitrogen atom bound with four alkyl groups whereas ammonia molecule contains one nitrogen centre bound to three hydrogen atoms.

Reference:

1.“第四纪铵化合物。”Quaternary Ammonium Compounds – an Overview | ScienceDirect Topics,Available here.

Image Courtesy:

1. “Ammonia-2D” By Radio89 – Own work(CC BY-SA 3.0)viaCommons Wikimedia
2. “Quaternary ammonium cation” By Fvasconcellos – Own work (Public Domain) viaCommons Wikimedia