Degree of Unsaturation (Index of Hydrogen Deficiency) (DU = (2C + 2 + N − H − X) / 2)
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DU = (2C + 2 + N − H − X) / 2
What each symbol means
| Symbol | What it stands for |
|---|---|
| C | Number of carbon atoms |
| H | Number of hydrogen atoms |
| N | Number of nitrogen atoms |
| X | Number of halogen atoms (count like H for saturation) |
When to use this
Neutral molecules; each ring or π bond adds 1 DU. O and S omitted from numerator. Adjust for charges if given.