The key difference between simazine and atrazine is that simazine is weakly soluble and more sediment-bound, whereas atrazine is a moderate to highly water-soluble pesticide that is more readily transported via surface runoff.
Simazine and atrazine are types of herbicides in the class of triazine compounds. Simazine is useful in controlling broad-leaved weeds and annual grasses, while atrazine is useful in preventing pre-emerging broadleaf weeds in crops.
CONTENTS
1. Overview and Key Difference
2. What is Simazine
3. What is Atrazine
4. Simazine vs Atrazine in Tabular Form
5. Summary – Simazine vs Atrazine
What is Simazine?
Simazine is a type of herbicide in the class of triazine compounds. We can use this substance to control broad-leaved weeds and annual grasses. The chemical formula of this compound is C7H12ClN5. Its molar mass is 201.66 g/mol. It appears as a white crystalline powder. Simazine has poor water solubility, but it is soluble in methanol, chloroform, and diethyl ether.
Figure 01: The Chemical Structure of Simazine
We can prepare simazine using cyanuric chloride and a concentrated solution of ethyl amine in water. This chemical reaction is highly exothermic, and therefore, it is usually carried out in an ice bath. Also, it is essential to carry out this synthesis under a fume hood. This is because cyanuric chloride typically decomposes at high temperatures, forming hydrogen chloride and hydrogen cyanide. Both these products are highly toxic to inhale.
Generally, simazine appears as an off-white crystalline compound, and it is a member of the triazine-derivative herbicides group. It was widely useful as a residual non-selective herbicide; however, now it is banned in Europe. This substance can act by inhibiting photosynthesis, which remains active in the soil for 2 – 7 months or longer.
What is Atrazine?
Atrazine is a type of herbicide in the triazine class that is useful in preventing pre-emerging broadleaf weeds in crops. These crops mainly include maize and sugarcane. The chemical formula of atrazine is C8H14ClN5. Its molar mass is about 215.69 g/mol. It appears as a colorless solid which decomposes at higher temperatures than 200 degrees Celsius. Moreover, it is poorly soluble in water.
Figure 02: The Chemical Structure of Atrazine
Atrazine was identified as the most commonly detected pesticide that contaminates drinking water in the USA. According to some research studies, it is an endocrine disruptor. Therefore, it is an agent that can alter that natural hormonal system.
We can prepare atrazine from cyanuric chloride. It is treated sequentially with ethylamine and isopropylamine. Similar to most other triazine herbicides, atrazine can function by binding to the plastoquinone-binding protein. Moreover, plant death comes from starvation and oxidative damage caused by the breakdown in the electron transport process.
What is the Difference Between Simazine and Atrazine?
Simazine and atrazine are important herbicide compounds. The key difference between simazine and atrazine is that simazine is weakly soluble and more sediment-bound, whereas atrazine is a moderate to highly water-soluble pesticide that is more readily transported via surface runoff. Moreover, simazine is useful in controlling broad-leaved weeds and annual grasses, while atrazine is useful in preventing pre-emerging broadleaf weeds in crops.
The below infographic presents the differences between simazine and atrazine in tabular form for side-by-side comparison.
Summary – Simazine vs Atrazine
The key difference between simazine and atrazine is that simazine is weakly soluble and more sediment-bound, whereas atrazine is a moderate to highly water-soluble pesticide that is more readily transported via surface runoff. Simazine is useful in controlling broad-leaved weeds and annual grasses, while atrazine is useful in preventing pre-emerging broadleaf weeds in crops.
Reference:
1. “Atrazine.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine.
Image Courtesy:
1. “Simazine” By Fvasconcellos 15:39, 18 April 2007 (UTC) – Own work (Public Domain) via Commons Wikimedia
2. “Atrazine Vector” By J3D3 – Own work (CC BY-SA 4.0) via Commons Wikimedia