The IUPAC name of terephthalic acid is Benzene-1,4-dicarboxylic acid.
Understanding Terephthalic Acid
Terephthalic acid is a crucial organic chemical compound widely used in various industrial applications, primarily as a precursor to polyester fibers and plastic bottles (PET). Its systematic naming is essential for clear communication in chemistry. You can find more information about its properties and uses on its Wikipedia page.
The Significance of IUPAC Nomenclature
The International Union of Pure and Applied Chemistry (IUPAC) provides a standardized system for naming chemical compounds. This global standard ensures that chemists, researchers, and industries worldwide can precisely identify a unique chemical structure regardless of language or region, preventing ambiguity and fostering clear scientific discourse.
Dissecting the IUPAC Name: Benzene-1,4-dicarboxylic acid
The IUPAC name Benzene-1,4-dicarboxylic acid precisely describes the molecular structure of terephthalic acid:
- Benzene: This indicates that the core of the molecule is a benzene ring, a cyclic aromatic hydrocarbon.
- 1,4-dicarboxylic acid: This specifies that there are two carboxylic acid functional groups (–COOH) attached to the benzene ring. The numbers "1,4" denote their positions on the benzene ring.
- In organic chemistry, positions on a benzene ring are numbered sequentially. "1,4" signifies that the two carboxylic acid groups are located directly opposite each other on the ring (a para-substitution pattern).
This systematic name unambiguously identifies terephthalic acid and distinguishes it from isomers like phthalic acid (benzene-1,2-dicarboxylic acid) or isophthalic acid (benzene-1,3-dicarboxylic acid), which have different arrangements of the carboxylic acid groups.
Other Common Names and Identifiers
While Benzene-1,4-dicarboxylic acid is the preferred IUPAC name, terephthalic acid is often known by several other common names and abbreviations in industry and everyday language. These alternative names are often shorter and more convenient for frequent use.
Here's a summary of its various names and identifiers:
| Category | Name/Identifier | Description |
|---|---|---|
| Preferred IUPAC | Benzene-1,4-dicarboxylic acid | The systematic name according to IUPAC rules. |
| Common Name | Terephthalic acid | The widely recognized trivial name. |
| Other Names | para-Phthalic acid | Highlights the para-substitution pattern. |
| Abbreviations | TPA | Common abbreviation in industry. |
| PTA | Another frequent abbreviation. | |
| BDC | Short for Benzene Dicarboxylic acid (less common in direct reference to terephthalic acid specifically). | |
| CAS Number | 100-21-0 | Chemical Abstracts Service registry number, a unique numerical identifier. |
