Write the systematic name of each organic molecule: structure name is a crucial skill for organic chemistry students and professionals alike. Understanding how to systematically name organic molecules based on their structure is essential for clear communication and accurate record-keeping in the field. This article will provide a comprehensive guide on how to systematically name organic molecules, focusing on the structure name component.
In organic chemistry, systematic naming follows a set of rules established by the International Union of Pure and Applied Chemistry (IUPAC). The systematic name of an organic molecule is composed of several parts, including the parent chain name, the locant (number indicating the position of substituents), the substituent names, and the functional group name. In this article, we will focus on the structure name, which is the parent chain name and the locant.
The first step in naming an organic molecule is to identify the parent chain. The parent chain is the longest continuous carbon chain in the molecule. To determine the parent chain, follow these guidelines:
1. Identify the longest carbon chain in the molecule.
2. If there are multiple chains of equal length, choose the chain with the most substituents.
3. If there are still multiple chains of equal length, choose the chain with the most multiple bonds.
Once the parent chain is identified, assign a locant to each substituent on the chain. The locant is a number that indicates the position of the substituent on the parent chain. The lowest possible locant is used for each substituent, and the locants are listed in alphabetical order.
Next, name the substituents. Substituents are atoms or groups of atoms attached to the parent chain. The following rules are used to name substituents:
1. Identify the substituent by its parent chain.
2. If the substituent is a halogen, name it as “halo-” followed by the name of the halogen (e.g., chloro, bromo, iodo).
3. If the substituent is a hydrocarbon, name it using the prefixes “alkyl,” “aryl,” “alkenyl,” or “alkynyl,” followed by the name of the parent chain (e.g., methyl, phenyl, propenyl, but-2-ynyl).
4. If the substituent is a functional group, name it using the appropriate prefix (e.g., hydroxyl, carboxyl, amine).
Finally, combine the parent chain name, locants, and substituent names to form the systematic name of the organic molecule. For example, consider the following molecule:
CH3-CH2-CH(Cl)-CH2-CH3
1. Identify the parent chain: The longest carbon chain is five carbons long, so the parent chain is pentane.
2. Assign locants: The chlorine atom is attached to the second carbon, so the locant is 2.
3. Name the substituent: The substituent is a chlorine atom, so the name is chloro.
4. Combine the names: The systematic name of the molecule is 2-chloropentane.
In conclusion, writing the systematic name of each organic molecule: structure name is a fundamental skill in organic chemistry. By following the rules outlined in this article, students and professionals can accurately and systematically name organic molecules based on their structure. This skill is essential for clear communication and accurate record-keeping in the field.
