The key difference between carbamates and organophosphates is that carbamates do not contain phosphate, whereas organophosphates essentially contain phosphate.
We can find the terms carbamates and organophosphates in the field of agriculture under the subcategory of insecticides. Both of these are organic compounds. They differ from each other according to the chemical structure and properties.
CONTENTS
1. Overview and Key Difference
2. What are Carbamates
3. What are Organophosphates
4. Side by Side Comparison – Carbamates vs. Organophosphates in Tabular Form
5. Summary
What are Carbamates?
Carbamates are organic compounds derived from carbamic acid. These compounds are ionic species that form through the replacement of one or more hydrogen atoms from the carbamic acid by other functional groups. Usually, most carbamic acid forms are unstable, but carbamate is a stable ionic species. Some carbamates are covalent compounds, while others are ionic compounds.
In water, we can observe the carbamate ion slowly gets into equilibrium with carbonate and bicarbonate anions. For example, calcium carbamate is water-soluble due to this equilibrium state, but calcium carbonate is insoluble in water.
The general formula of carbamate anion is H2NCOO−. There are two oxygen atoms in carbamate anion. Either both of the oxygen atoms or one of them can be replaced by sulfur atoms. The products from these replacements are called the analogues of carbamate. When oxygen atoms are replaced by sulfur atoms, the product is called thiocarbamates. If both oxygen atoms are replaced by sulfur atoms, then the product is dithiocarbamate.
Figure 01: General Formula of Carbamate
Ammonium carbamate is very important as a fertilizer in agriculture. It is a salt of ammonia, and we can produce it via the treatment of ammonia with carbon dioxide. However, we can find naturally occurring carbamates as well. For instance, N-terminal amino groups of valine residues in hemoglobin exits as carbamates.
What are Organophosphates?
Organophosphates are a group of organic compounds which have the general structure O=P(OR)3. These are esters of phosphoric acid. We can observe organophosphates occur in a diverse range of forms, such as DNA, RNA, insecticides, herbicides, etc. When considering the properties of organophosphates, these compounds are acidic due to the presence of –OH groups which are acidic (they can donate protons). They can get partially deprotonated in an aqueous solution.
There are many different routes for the synthesis of organophosphates. For example, esterification of phosphoric acid, oxidation of phosphite esters, alcoholysis of phosphorus oxychloride, etc. However, we can find a naturally occurring organophosphate that is produced by cyanobacteria, anatoxin.
Figure 02: General Structure of Organophosphates
The major application of organophosphates in the field of agriculture is as insecticides. These compounds can act on the enzyme acetylcholinesterase present in insects. Moreover, these compounds can inhibit the action of neuromuscular enzymes. These enzymes are known to be broadly required for the proper function of the insects.
What is the Difference Between Carbamates and Organophosphates?
We can find the terms carbamates and organophosphates in the field of agriculture under the subcategory of insecticides. The key difference between carbamates and organophosphates is that carbamates do not contain phosphate, whereas organophosphates essentially contain phosphate. The general formula of carbamates is H2NCOO− while the general formula of organophosphates is O=P(OR)3. We can produce carbamates via treating ammonia with carbon dioxide. However, we can prepare organophosphates via different methods including, esterification of phosphoric acid, oxidation of phosphite esters, alcoholysis of phosphorus oxychloride, etc.
Below infographic summarizes the difference between carbamates and organophosphates.
Summary – Carbamates vs. Organophosphates
We can find the terms carbamates and organophosphates in the field of agriculture under the subcategory of insecticides. The key difference between carbamates and organophosphates is that carbamates do not contain phosphate, whereas organophosphates essentially contain phosphate.
Reference:
1. Tiwari, Balkrishna, et al. “Pesticides and Rice Agriculture.” Cyanobacteria, 2019, pp. 303–325., doi:10.1016/b978-0-12-814667-5.00015-5.
Image Courtesy:
1. “Carbamate-group-2D” By Ben Mills – Own work (Public Domain) via Commons Wikimedia
2. “Phosphate formula” By Snubcube (talk) – Own work (Public Domain) via Commons Wikimedia