Nomenclatura IUPAC
La IUPAC (Unión Internacional de Química Pura y Aplicada) creó reglas para que cada compuesto orgánico tenga un nombre único basado en su estructura. Esta página resume las reglas principales y permite comprobar moléculas en el simulador.
Estructura general de un nombre IUPAC
Un nombre sistemático sigue este patrón:
Por ejemplo, en 2-methylbutan-2-ol: "2-methyl" is the substituent prefix, "but" indicates a 4-carbon chain, "an" indicates only single bonds, and "2-ol" is the alcohol suffix at position 2.
1. Encontrar la cadena principal
La cadena principal is the longest one containing the highest-priority functional group (see the full order in functional groups). In case of a tie in length, the chain with more branches is chosen.
2. Prefijos numéricos (número de carbonos)
| Carbonos | Prefijo | Carbonos | Prefijo |
|---|---|---|---|
| 1 | meth | 6 | hex |
| 2 | eth | 7 | hept |
| 3 | prop | 8 | oct |
| 4 | but | 9 | non |
| 5 | pent | 10 | dec |
3. Numerar la cadena (localizadores)
Numbering starts from the end that gives the lowest locant to the main group. In case of a tie, the lowest set of locants goes to unsaturations (double/triple bonds), then to substituents, with alphabetical order breaking further ties.
4. Sufijos por función (resumen)
| Función | Sufijo | Ejemplo |
|---|---|---|
| Alcohol | -ol | ethanol |
| Aldehyde | -al | methanal |
| Ketone | -one | propanone |
| Carboxylic acid | -oic acid | ethanoic acid |
| Amine | -amine | methanamine |
| Nitrile | -nitrile | ethanenitrile |
See each functional group page for specific rules (esters and ethers, for example, don't follow this simple single-suffix pattern).
5. Prefijos de sustituyentes y multiplicadores
Branches and secondary groups (that aren't the main group) become prefixes, in alphabetical order: chloro-, methyl-, hydroxy-, etc. When the same substituent repeats, di-, tri-, tetra- are used (which don't count for alphabetical ordering).
Test these rules in the simulator →